diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-28 12:14:19 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-28 12:14:19 -0700 |
| commit | 54a728dc5e4feb0a9278ad62b19f34ad21ed0ee4 (patch) | |
| tree | 2737c23d4dbc6426d6d9467626a7634cbbb40fcd | |
| parent | 28a27cbd86076c1a6be311c751b421c4c17a7dd9 (diff) | |
| parent | adf3c31e18b765ea24eba7b0c1efc076b8ee3d55 (diff) | |
| download | linux-54a728dc5e4feb0a9278ad62b19f34ad21ed0ee4.tar.bz2 | |
Merge tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler udpates from Ingo Molnar:
- Changes to core scheduling facilities:
- Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables
coordinated scheduling across SMT siblings. This is a much
requested feature for cloud computing platforms, to allow the
flexible utilization of SMT siblings, without exposing untrusted
domains to information leaks & side channels, plus to ensure more
deterministic computing performance on SMT systems used by
heterogenous workloads.
There are new prctls to set core scheduling groups, which allows
more flexible management of workloads that can share siblings.
- Fix task->state access anti-patterns that may result in missed
wakeups and rename it to ->__state in the process to catch new
abuses.
- Load-balancing changes:
- Tweak newidle_balance for fair-sched, to improve 'memcache'-like
workloads.
- "Age" (decay) average idle time, to better track & improve
workloads such as 'tbench'.
- Fix & improve energy-aware (EAS) balancing logic & metrics.
- Fix & improve the uclamp metrics.
- Fix task migration (taskset) corner case on !CONFIG_CPUSET.
- Fix RT and deadline utilization tracking across policy changes
- Introduce a "burstable" CFS controller via cgroups, which allows
bursty CPU-bound workloads to borrow a bit against their future
quota to improve overall latencies & batching. Can be tweaked via
/sys/fs/cgroup/cpu/<X>/cpu.cfs_burst_us.
- Rework assymetric topology/capacity detection & handling.
- Scheduler statistics & tooling:
- Disable delayacct by default, but add a sysctl to enable it at
runtime if tooling needs it. Use static keys and other
optimizations to make it more palatable.
- Use sched_clock() in delayacct, instead of ktime_get_ns().
- Misc cleanups and fixes.
* tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
sched/doc: Update the CPU capacity asymmetry bits
sched/topology: Rework CPU capacity asymmetry detection
sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag
psi: Fix race between psi_trigger_create/destroy
sched/fair: Introduce the burstable CFS controller
sched/uclamp: Fix uclamp_tg_restrict()
sched/rt: Fix Deadline utilization tracking during policy change
sched/rt: Fix RT utilization tracking during policy change
sched: Change task_struct::state
sched,arch: Remove unused TASK_STATE offsets
sched,timer: Use __set_current_state()
sched: Add get_current_state()
sched,perf,kvm: Fix preemption condition
sched: Introduce task_is_running()
sched: Unbreak wakeups
sched/fair: Age the average idle time
sched/cpufreq: Consider reduced CPU capacity in energy calculation
sched/fair: Take thermal pressure into account while estimating energy
thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure
sched/fair: Return early from update_tg_cfs_load() if delta == 0
...
139 files changed, 3122 insertions, 781 deletions
diff --git a/Documentation/accounting/delay-accounting.rst b/Documentation/accounting/delay-accounting.rst index 7cc7f5852da0..1b8b46deeb29 100644 --- a/Documentation/accounting/delay-accounting.rst +++ b/Documentation/accounting/delay-accounting.rst @@ -69,13 +69,15 @@ Compile the kernel with:: CONFIG_TASK_DELAY_ACCT=y CONFIG_TASKSTATS=y -Delay accounting is enabled by default at boot up. -To disable, add:: +Delay accounting is disabled by default at boot up. +To enable, add:: - nodelayacct + delayacct -to the kernel boot options. The rest of the instructions -below assume this has not been done. +to the kernel boot options. The rest of the instructions below assume this has +been done. Alternatively, use sysctl kernel.task_delayacct to switch the state +at runtime. Note however that only tasks started after enabling it will have +delayacct information. After the system has booted up, use a utility similar to getdelays.c to access the delays diff --git a/Documentation/admin-guide/hw-vuln/core-scheduling.rst b/Documentation/admin-guide/hw-vuln/core-scheduling.rst new file mode 100644 index 000000000000..7b410aef9c5c --- /dev/null +++ b/Documentation/admin-guide/hw-vuln/core-scheduling.rst @@ -0,0 +1,223 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=============== +Core Scheduling +=============== +Core scheduling support allows userspace to define groups of tasks that can +share a core. These groups can be specified either for security usecases (one +group of tasks don't trust another), or for performance usecases (some +workloads may benefit from running on the same core as they don't need the same +hardware resources of the shared core, or may prefer different cores if they +do share hardware resource needs). This document only describes the security +usecase. + +Security usecase +---------------- +A cross-HT attack involves the attacker and victim running on different Hyper +Threads of the same core. MDS and L1TF are examples of such attacks. The only +full mitigation of cross-HT attacks is to disable Hyper Threading (HT). Core +scheduling is a scheduler feature that can mitigate some (not all) cross-HT +attacks. It allows HT to be turned on safely by ensuring that only tasks in a +user-designated trusted group can share a core. This increase in core sharing +can also improve performance, however it is not guaranteed that performance +will always improve, though that is seen to be the case with a number of real +world workloads. In theory, core scheduling aims to perform at least as good as +when Hyper Threading is disabled. In practice, this is mostly the case though +not always: as synchronizing scheduling decisions across 2 or more CPUs in a +core involves additional overhead - especially when the system is lightly +loaded. When ``total_threads <= N_CPUS/2``, the extra overhead may cause core +scheduling to perform more poorly compared to SMT-disabled, where N_CPUS is the +total number of CPUs. Please measure the performance of your workloads always. + +Usage +----- +Core scheduling support is enabled via the ``CONFIG_SCHED_CORE`` config option. +Using this feature, userspace defines groups of tasks that can be co-scheduled +on the same core. The core scheduler uses this information to make sure that +tasks that are not in the same group never run simultaneously on a core, while +doing its best to satisfy the system's scheduling requirements. + +Core scheduling can be enabled via the ``PR_SCHED_CORE`` prctl interface. +This interface provides support for the creation of core scheduling groups, as +well as admission and removal of tasks from created groups:: + + #include <sys/prctl.h> + + int prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5); + +option: + ``PR_SCHED_CORE`` + +arg2: + Command for operation, must be one off: + + - ``PR_SCHED_CORE_GET`` -- get core_sched cookie of ``pid``. + - ``PR_SCHED_CORE_CREATE`` -- create a new unique cookie for ``pid``. + - ``PR_SCHED_CORE_SHARE_TO`` -- push core_sched cookie to ``pid``. + - ``PR_SCHED_CORE_SHARE_FROM`` -- pull core_sched cookie from ``pid``. + +arg3: + ``pid`` of the task for which the operation applies. + +arg4: + ``pid_type`` for which the operation applies. It is of type ``enum pid_type``. + For example, if arg4 is ``PIDTYPE_TGID``, then the operation of this command + will be performed for all tasks in the task group of ``pid``. + +arg5: + userspace pointer to an unsigned long for storing the cookie returned by + ``PR_SCHED_CORE_GET`` command. Should be 0 for all other commands. + +In order for a process to push a cookie to, or pull a cookie from a process, it +is required to have the ptrace access mode: `PTRACE_MODE_READ_REALCREDS` to the +process. + +Building hierarchies of tasks +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The simplest way to build hierarchies of threads/processes which share a +cookie and thus a core is to rely on the fact that the core-sched cookie is +inherited across forks/clones and execs, thus setting a cookie for the +'initial' script/executable/daemon will place every spawned child in the +same core-sched group. + +Cookie Transferral +~~~~~~~~~~~~~~~~~~ +Transferring a cookie between the current and other tasks is possible using +PR_SCHED_CORE_SHARE_FROM and PR_SCHED_CORE_SHARE_TO to inherit a cookie from a +specified task or a share a cookie with a task. In combination this allows a +simple helper program to pull a cookie from a task in an existing core +scheduling group and share it with already running tasks. + +Design/Implementation +--------------------- +Each task that is tagged is assigned a cookie internally in the kernel. As +mentioned in `Usage`_, tasks with the same cookie value are assumed to trust +each other and share a core. + +The basic idea is that, every schedule event tries to select tasks for all the +siblings of a core such that all the selected tasks running on a core are +trusted (same cookie) at any point in time. Kernel threads are assumed trusted. +The idle task is considered special, as it trusts everything and everything +trusts it. + +During a schedule() event on any sibling of a core, the highest priority task on +the sibling's core is picked and assigned to the sibling calling schedule(), if +the sibling has the task enqueued. For rest of the siblings in the core, +highest priority task with the same cookie is selected if there is one runnable +in their individual run queues. If a task with same cookie is not available, +the idle task is selected. Idle task is globally trusted. + +Once a task has been selected for all the siblings in the core, an IPI is sent to +siblings for whom a new task was selected. Siblings on receiving the IPI will +switch to the new task immediately. If an idle task is selected for a sibling, +then the sibling is considered to be in a `forced idle` state. I.e., it may +have tasks on its on runqueue to run, however it will still have to run idle. +More on this in the next section. + +Forced-idling of hyperthreads +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The scheduler tries its best to find tasks that trust each other such that all +tasks selected to be scheduled are of the highest priority in a core. However, +it is possible that some runqueues had tasks that were incompatible with the +highest priority ones in the core. Favoring security over fairness, one or more +siblings could be forced to select a lower priority task if the highest +priority task is not trusted with respect to the core wide highest priority +task. If a sibling does not have a trusted task to run, it will be forced idle +by the scheduler (idle thread is scheduled to run). + +When the highest priority task is selected to run, a reschedule-IPI is sent to +the sibling to force it into idle. This results in 4 cases which need to be +considered depending on whether a VM or a regular usermode process was running +on either HT:: + + HT1 (attack) HT2 (victim) + A idle -> user space user space -> idle + B idle -> user space guest -> idle + C idle -> guest user space -> idle + D idle -> guest guest -> idle + +Note that for better performance, we do not wait for the destination CPU +(victim) to enter idle mode. This is because the sending of the IPI would bring +the destination CPU immediately into kernel mode from user space, or VMEXIT +in the case of guests. At best, this would only leak some scheduler metadata +which may not be worth protecting. It is also possible that the IPI is received +too late on some architectures, but this has not been observed in the case of +x86. + +Trust model +~~~~~~~~~~~ +Core scheduling maintains trust relationships amongst groups of tasks by +assigning them a tag that is the same cookie value. +When a system with core scheduling boots, all tasks are considered to trust +each other. This is because the core scheduler does not have information about +trust relationships until userspace uses the above mentioned interfaces, to +communicate them. In other words, all tasks have a default cookie value of 0. +and are considered system-wide trusted. The forced-idling of siblings running +cookie-0 tasks is also avoided. + +Once userspace uses the above mentioned interfaces to group sets of tasks, tasks +within such groups are considered to trust each other, but do not trust those +outside. Tasks outside the group also don't trust tasks within. + +Limitations of core-scheduling +------------------------------ +Core scheduling tries to guarantee that only trusted tasks run concurrently on a +core. But there could be small window of time during which untrusted tasks run +concurrently or kernel could be running concurrently with a task not trusted by +kernel. + +IPI processing delays +~~~~~~~~~~~~~~~~~~~~~ +Core scheduling selects only trusted tasks to run together. IPI is used to notify +the siblings to switch to the new task. But there could be hardware delays in +receiving of the IPI on some arch (on x86, this has not been observed). This may +cause an attacker task to start running on a CPU before its siblings receive the +IPI. Even though cache is flushed on entry to user mode, victim tasks on siblings +may populate data in the cache and micro architectural buffers after the attacker +starts to run and this is a possibility for data leak. + +Open cross-HT issues that core scheduling does not solve +-------------------------------------------------------- +1. For MDS +~~~~~~~~~~ +Core scheduling cannot protect against MDS attacks between an HT running in +user mode and another running in kernel mode. Even though both HTs run tasks +which trust each other, kernel memory is still considered untrusted. Such +attacks are possible for any combination of sibling CPU modes (host or guest mode). + +2. For L1TF +~~~~~~~~~~~ +Core scheduling cannot protect against an L1TF guest attacker exploiting a +guest or host victim. This is because the guest attacker can craft invalid +PTEs which are not inverted due to a vulnerable guest kernel. The only +solution is to disable EPT (Extended Page Tables). + +For both MDS and L1TF, if the guest vCPU is configured to not trust each +other (by tagging separately), then the guest to guest attacks would go away. +Or it could be a system admin policy which considers guest to guest attacks as +a guest problem. + +Another approach to resolve these would be to make every untrusted task on the +system to not trust every other untrusted task. While this could reduce +parallelism of the untrusted tasks, it would still solve the above issues while +allowing system processes (trusted tasks) to share a core. + +3. Protecting the kernel (IRQ, syscall, VMEXIT) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Unfortunately, core scheduling does not protect kernel contexts running on +sibling hyperthreads from one another. Prototypes of mitigations have been posted +to LKML to solve this, but it is debatable whether such windows are practically +exploitable, and whether the performance overhead of the prototypes are worth +it (not to mention, the added code complexity). + +Other Use cases +--------------- +The main use case for Core scheduling is mitigating the cross-HT vulnerabilities +with SMT enabled. There are other use cases where this feature could be used: + +- Isolating tasks that needs a whole core: Examples include realtime tasks, tasks + that uses SIMD instructions etc. +- Gang scheduling: Requirements for a group of tasks that needs to be scheduled + together could also be realized using core scheduling. One example is vCPUs of + a VM. diff --git a/Documentation/admin-guide/hw-vuln/index.rst b/Documentation/admin-guide/hw-vuln/index.rst index ca4dbdd9016d..f12cda55538b 100644 --- a/Documentation/admin-guide/hw-vuln/index.rst +++ b/Documentation/admin-guide/hw-vuln/index.rst @@ -15,3 +15,4 @@ are configurable at compile, boot or run time. tsx_async_abort multihit.rst special-register-buffer-data-sampling.rst + core-scheduling.rst diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbdedc46..ef5048c127a3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3244,7 +3244,7 @@ noclflush [BUGS=X86] Don't use the CLFLUSH instruction - nodelayacct [KNL] Disable per-task delay accounting + delayacct [KNL] Enable per-task delay accounting nodsp [SH] Disable hardware DSP at boot time. diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 68b21395a743..0ef05750dadc 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -1088,6 +1088,13 @@ Model available). If your platform happens to meet the requirements for EAS but you do not want to use it, change this value to 0. +task_delayacct +=============== + +Enables/disables task delay accounting (see +:doc:`accounting/delay-accounting.rst`). Enabling this feature incurs +a small amount of overhead in the scheduler but is useful for debugging +and performance tuning. It is required by some tools such as iotop. sched_schedstats ================ diff --git a/Documentation/scheduler/sched-capacity.rst b/Documentation/scheduler/sched-capacity.rst index 9b7cbe43b2d1..805f85f330b5 100644 --- a/Documentation/scheduler/sched-capacity.rst +++ b/Documentation/scheduler/sched-capacity.rst @@ -284,8 +284,10 @@ whether the system exhibits asymmetric CPU capacities. Should that be the case: - The sched_asym_cpucapacity static key will be enabled. -- The SD_ASYM_CPUCAPACITY flag will be set at the lowest sched_domain level that - spans all unique CPU capacity values. +- The SD_ASYM_CPUCAPACITY_FULL flag will be set at the lowest sched_domain + level that spans all unique CPU capacity values. +- The SD_ASYM_CPUCAPACITY flag will be set for any sched_domain that spans + CPUs with any range of asymmetry. The sched_asym_cpucapacity static key is intended to guard sections of code that cater to asymmetric CPU capacity systems. Do note however that said key is diff --git a/Documentation/scheduler/sched-energy.rst b/Documentation/scheduler/sched-energy.rst index afe02d394402..8fbce5e767d9 100644 --- a/Documentation/scheduler/sched-energy.rst +++ b/Documentation/scheduler/sched-energy.rst @@ -328,7 +328,7 @@ section lists these dependencies and provides hints as to how they can be met. As mentioned in the introduction, EAS is only supported on platforms with asymmetric CPU topologies for now. This requirement is checked at run-time by -looking for the presence of the SD_ASYM_CPUCAPACITY flag when the scheduling +looking for the presence of the SD_ASYM_CPUCAPACITY_FULL flag when the scheduling domains are built. See Documentation/scheduler/sched-capacity.rst for requirements to be met for this diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index 5112ab996394..ef0c08ed0481 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -380,7 +380,7 @@ get_wchan(struct task_struct *p) { unsigned long schedule_frame; unsigned long pc; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; /* * This one depends on the frame size of schedule(). Do a diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index f4dd9f3f3001..4b2575f936d4 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -166,7 +166,6 @@ smp_callin(void) DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n", cpuid, current, current->active_mm)); - preempt_disable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c index 52906d314537..db0e104d6835 100644 --- a/arch/arc/kernel/smp.c +++ b/arch/arc/kernel/smp.c @@ -189,7 +189,6 @@ void start_kernel_secondary(void) pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu); local_irq_enable(); - preempt_disable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c index f73da203b170..1b9576d21e24 100644 --- a/arch/arc/kernel/stacktrace.c +++ b/arch/arc/kernel/stacktrace.c @@ -83,7 +83,7 @@ seed_unwind_frame_info(struct task_struct *tsk, struct pt_regs *regs, * is safe-kept and BLINK at a well known location in there */ - if (tsk->state == TASK_RUNNING) + if (task_is_running(tsk)) return -1; frame_info->task = tsk; diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 6324f4db9b02..fc9e8b37eaa8 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -288,7 +288,7 @@ unsigned long get_wchan(struct task_struct *p) struct stackframe frame; unsigned long stack_page; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; frame.fp = thread_saved_fp(p); diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 74679240a9d8..c7bb168b0d97 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -432,7 +432,6 @@ asmlinkage void secondary_start_kernel(void) #endif pr_debug("CPU%u: Booted secondary processor\n", cpu); - preempt_disable(); trace_hardirqs_off(); /* diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h index 80e946b2abee..e83f0982b99c 100644 --- a/arch/arm64/include/asm/preempt.h +++ b/arch/arm64/include/asm/preempt.h @@ -23,7 +23,7 @@ static inline void preempt_count_set(u64 pc) } while (0) #define init_idle_preempt_count(p, cpu) do { \ - task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ } while (0) static inline void set_preempt_need_resched(void) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index b4bb67f17a2c..14f3c19c6ad2 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -598,7 +598,7 @@ unsigned long get_wchan(struct task_struct *p) struct stackframe frame; unsigned long stack_page, ret = 0; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; stack_page = (unsigned long)try_get_task_stack(p); diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index dcd7041b2b07..6671000a8b7d 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -224,7 +224,6 @@ asmlinkage notrace void secondary_start_kernel(void) init_gic_priority_masking(); rcu_cpu_starting(cpu); - preempt_disable(); trace_hardirqs_off(); /* diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 3964acf5451e..a4eba0908bfa 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -20,8 +20,6 @@ if VIRTUALIZATION menuconfig KVM bool "Kernel-based Virtual Machine (KVM) support" depends on OF - # for TASKSTATS/TASK_DELAY_ACCT: - depends on NET && MULTIUSER select MMU_NOTIFIER select PREEMPT_NOTIFIERS select HAVE_KVM_CPU_RELAX_INTERCEPT @@ -38,8 +36,7 @@ menuconfig KVM select IRQ_BYPASS_MANAGER select HAVE_KVM_IRQ_BYPASS select HAVE_KVM_VCPU_RUN_PID_CHANGE - select TASKSTATS - select TASK_DELAY_ACCT + select SCHED_INFO help Support hosting virtualized guest machines. diff --git a/arch/csky/kernel/asm-offsets.c b/arch/csky/kernel/asm-offsets.c index 17479860d43d..1cbcba4b0dd1 100644 --- a/arch/csky/kernel/asm-offsets.c +++ b/arch/csky/kernel/asm-offsets.c @@ -9,7 +9,6 @@ int main(void) { /* offsets into the task struct */ - DEFINE(TASK_STATE, offsetof(struct task_struct, state)); DEFINE(TASK_THREAD_INFO, offsetof(struct task_struct, stack)); DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags)); DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace)); diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c index 0f9f5eef9338..e2993539af8e 100644 --- a/arch/csky/kernel/smp.c +++ b/arch/csky/kernel/smp.c @@ -281,7 +281,6 @@ void csky_start_secondary(void) pr_info("CPU%u Online: %s...\n", cpu, __func__); local_irq_enable(); - preempt_disable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/csky/kernel/stacktrace.c b/arch/csky/kernel/stacktrace.c index 16ae20a0af34..1b280ef08004 100644 --- a/arch/csky/kernel/stacktrace.c +++ b/arch/csky/kernel/stacktrace.c @@ -115,7 +115,7 @@ unsigned long get_wchan(struct task_struct *task) { unsigned long pc = 0; - if (likely(task && task != current && task->state != TASK_RUNNING)) + if (likely(task && task != current && !task_is_running(task))) walk_stackframe(task, NULL, save_wchan, &pc); return pc; } diff --git a/arch/h8300/kernel/asm-offsets.c b/arch/h8300/kernel/asm-offsets.c index d4b53af657c8..65571ee15132 100644 --- a/arch/h8300/kernel/asm-offsets.c +++ b/arch/h8300/kernel/asm-offsets.c @@ -21,7 +21,6 @@ int main(void) { /* offsets into the task struct */ - OFFSET(TASK_STATE, task_struct, state); OFFSET(TASK_FLAGS, task_struct, flags); OFFSET(TASK_PTRACE, task_struct, ptrace); OFFSET(TASK_BLOCKED, task_struct, blocked); diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c index 46b1342ce515..2ac27e4248a4 100644 --- a/arch/h8300/kernel/process.c +++ b/arch/h8300/kernel/process.c @@ -134,7 +134,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long stack_page; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; stack_page = (unsigned long)p; diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c index c61165c99ae0..6a6835fb4242 100644 --- a/arch/hexagon/kernel/process.c +++ b/arch/hexagon/kernel/process.c @@ -135,7 +135,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long fp, pc; unsigned long stack_page; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; stack_page = (unsigned long)task_stack_page(p); diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c index cdbac4b52f30..e628a88607bb 100644 --- a/arch/ia64/kernel/mca.c +++ b/arch/ia64/kernel/mca.c @@ -1788,7 +1788,7 @@ format_mca_init_stack(void *mca_data, unsigned long offset, ti->task = p; ti->cpu = cpu; p->stack = ti; - p->state = TASK_UNINTERRUPTIBLE; + p->__state = TASK_UNINTERRUPTIBLE; cpumask_set_cpu(cpu, &p->cpus_mask); INIT_LIST_HEAD(&p->tasks); p->parent = p->real_parent = p->group_leader = p; diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 7e1a1525e202..e56d63f4abf9 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -529,7 +529,7 @@ get_wchan (struct task_struct *p) unsigned long ip; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; /* @@ -542,7 +542,7 @@ get_wchan (struct task_struct *p) */ unw_init_from_blocked_task(&info, p); do { - if (p->state == TASK_RUNNING) + if (task_is_running(p)) return 0; if (unw_unwind(&info) < 0) return 0; diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index e14f5653393a..df28c7dd164f 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -641,11 +641,11 @@ ptrace_attach_sync_user_rbs (struct task_struct *child) read_lock(&tasklist_lock); if (child->sighand) { spin_lock_irq(&child->sighand->siglock); - if (child->state == TASK_STOPPED && + if (READ_ONCE(child->__state) == TASK_STOPPED && !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) { set_notify_resume(child); - child->state = TASK_TRACED; + WRITE_ONCE(child->__state, TASK_TRACED); stopped = 1; } spin_unlock_irq(&child->sighand->siglock); @@ -665,9 +665,9 @@ ptrace_attach_sync_user_rbs (struct task_struct *child) read_lock(&tasklist_lock); if (child->sighand) { spin_lock_irq(&child->sighand->siglock); - if (child->state == TASK_TRACED && + if (READ_ONCE(child->__state) == TASK_TRACED && (child->signal->flags & SIGNAL_STOP_STOPPED)) { - child->state = TASK_STOPPED; + WRITE_ONCE(child->__state, TASK_STOPPED); } spin_unlock_irq(&child->sighand->siglock); } diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 49b488580939..d10f780c13b9 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -441,7 +441,6 @@ start_secondary (void *unused) #endif efi_map_pal_code(); cpu_init(); - preempt_disable(); smp_callin(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c index da83cc83e791..db49f9091711 100644 --- a/arch/m68k/kernel/process.c +++ b/arch/m68k/kernel/process.c @@ -268,7 +268,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long fp, pc; unsigned long stack_page; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; stack_page = (unsigned long)task_stack_page(p); diff --git a/arch/microblaze/kernel/asm-offsets.c b/arch/microblaze/kernel/asm-offsets.c index 6c69ce7be2e8..b77dd188dec4 100644 --- a/arch/microblaze/kernel/asm-offsets.c +++ b/arch/microblaze/kernel/asm-offsets.c @@ -70,7 +70,6 @@ int main(int argc, char *argv[]) /* struct task_struct */ DEFINE(TS_THREAD_INFO, offsetof(struct task_struct, stack)); - DEFINE(TASK_STATE, offsetof(struct task_struct, state)); DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags)); DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace)); DEFINE(TASK_BLOCKED, offsetof(struct task_struct, blocked)); diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c index 5735b2cd6f2a..04ca75278f02 100644 --- a/arch/mips/kernel/asm-offsets.c +++ b/arch/mips/kernel/asm-offsets.c @@ -78,7 +78,6 @@ void output_ptreg_defines(void) void output_task_defines(void) { COMMENT("MIPS task_struct offsets."); - OFFSET(TASK_STATE, task_struct, state); OFFSET(TASK_THREAD_INFO, task_struct, stack); OFFSET(TASK_FLAGS, task_struct, flags); OFFSET(TASK_MM, task_struct, mm); diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index bff080db0294..73c8e7990a97 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -662,7 +662,7 @@ unsigned long get_wchan(struct task_struct *task) unsigned long ra = 0; #endif - if (!task || task == current || task->state == TASK_RUNNING) + if (!task || task == current || task_is_running(task)) goto out; if (!task_stack_page(task)) goto out; diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index ef86fbad8546..d542fb7af3ba 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -348,7 +348,6 @@ asmlinkage void start_secondary(void) */ calibrate_delay(); - preempt_disable(); cpu = smp_processor_id(); cpu_data[cpu].udelay_val = loops_per_jiffy; diff --git a/arch/nds32/kernel/process.c b/arch/nds32/kernel/process.c index c1327e552ec6..391895b54d13 100644 --- a/arch/nds32/kernel/process.c +++ b/arch/nds32/kernel/process.c @@ -239,7 +239,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long stack_start, stack_end; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; if (IS_ENABLED(CONFIG_FRAME_POINTER)) { diff --git a/arch/nios2/kernel/process.c b/arch/nios2/kernel/process.c index c5f916ca6845..9ff37ba2bb60 100644 --- a/arch/nios2/kernel/process.c +++ b/arch/nios2/kernel/process.c @@ -223,7 +223,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long stack_page; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; stack_page = (unsigned long)p; diff --git a/arch/openrisc/kernel/asm-offsets.c b/arch/openrisc/kernel/asm-offsets.c index 18c703d1d761..710651d5aaae 100644 --- a/arch/openrisc/kernel/asm-offsets.c +++ b/arch/openrisc/kernel/asm-offsets.c @@ -37,7 +37,6 @@ int main(void) { /* offsets into the task_struct */ - DEFINE(TASK_STATE, offsetof(struct task_struct, state)); DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags)); DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace)); DEFINE(TASK_THREAD, offsetof(struct task_struct, thread)); diff --git a/arch/openrisc/kernel/smp.c b/arch/openrisc/kernel/smp.c index 48e1092a64de..415e209732a3 100644 --- a/arch/openrisc/kernel/smp.c +++ b/arch/openrisc/kernel/smp.c @@ -145,8 +145,6 @@ asmlinkage __init void secondary_start_kernel(void) set_cpu_online(cpu, true); local_irq_enable(); - - preempt_disable(); /* * OK, it's off to the idle thread for us */ diff --git a/arch/parisc/kernel/asm-offsets.c b/arch/parisc/kernel/asm-offsets.c index cd2cc1b1648c..33113ba24054 100644 --- a/arch/parisc/kernel/asm-offsets.c +++ b/arch/parisc/kernel/asm-offsets.c @@ -42,7 +42,6 @@ int main(void) { DEFINE(TASK_THREAD_INFO, offsetof(struct task_struct, stack)); - DEFINE(TASK_STATE, offsetof(struct task_struct, state)); DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags)); DEFINE(TASK_SIGPENDING, offsetof(struct task_struct, pending)); DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace)); diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index b144fbe29bc1..184ec3c1eae4 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -249,7 +249,7 @@ get_wchan(struct task_struct *p) unsigned long ip; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; /* @@ -260,7 +260,7 @@ get_wchan(struct task_struct *p) do { if (unwind_once(&info) < 0) return 0; - if (p->state == TASK_RUNNING) + if (task_is_running(p)) return 0; ip = info.ip; if (!in_sched_functions(ip)) diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index 10227f667c8a..1405b603b91b 100644 --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -302,7 +302,6 @@ void __init smp_callin(unsigned long pdce_proc) #endif smp_cpu_init(slave_id); - preempt_disable(); flush_cache_all_local(); /* start with known state */ flush_tlb_all_local(NULL); diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 89e34aa273e2..8935c5696bce 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -2084,7 +2084,7 @@ static unsigned long __get_wchan(struct task_struct *p) unsigned long ip, sp; int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; sp = p->thread.ksp; @@ -2094,7 +2094,7 @@ static unsigned long __get_wchan(struct task_struct *p) do { sp = *(unsigned long *)sp; if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) || - p->state == TASK_RUNNING) + task_is_running(p)) return 0; if (count > 0) { ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 2e05c783440a..6c6e4d934d86 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1547,7 +1547,6 @@ void start_secondary(void *unused) smp_store_cpu_info(cpu); set_dec(tb_ticks_per_jiffy); rcu_cpu_starting(cpu); - preempt_disable(); cpu_callin_map[cpu] = 1; if (smp_ops->setup_cpu) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index c8173e92f19d..84de2d7c2f40 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -3162,6 +3162,7 @@ memzcan(void) static void show_task(struct task_struct *tsk) { + unsigned int p_state = READ_ONCE(tsk->__state); char state; /* @@ -3169,14 +3170,14 @@ static void show_task(struct task_struct *tsk) * appropriate for calling from xmon. This could be moved * to a common, generic, routine used by both. */ - state = (tsk->state == 0) ? 'R' : - (tsk->state < 0) ? 'U' : - (tsk->state & TASK_UNINTERRUPTIBLE) ? 'D' : - (tsk->state & TASK_STOPPED) ? 'T' : - (tsk->state & TASK_TRACED) ? 'C' : + state = (p_state == 0) ? 'R' : + (p_state < 0) ? 'U' : + (p_state & TASK_UNINTERRUPTIBLE) ? 'D' : + (p_state & TASK_STOPPED) ? 'T' : + (p_state & TASK_TRACED) ? 'C' : (tsk->exit_state & EXIT_ZOMBIE) ? 'Z' : (tsk->exit_state & EXIT_DEAD) ? 'E' : - (tsk->state & TASK_INTERRUPTIBLE) ? 'S' : '?'; + (p_state & TASK_INTERRUPTIBLE) ? 'S' : '?'; printf("%16px %16lx %16px %6d %6d %c %2d %s\n", tsk, tsk->thread.ksp, tsk->thread.regs, diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 9a408e2942ac..bd82375db51a 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -180,7 +180,6 @@ asmlinkage __visible void smp_callin(void) * Disable preemption before enabling interrupts, so we don't try to * schedule a CPU that hasn't actually started yet. */ - preempt_disable(); local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index bde85fc53357..ff467b98c3e3 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -132,7 +132,7 @@ unsigned long get_wchan(struct task_struct *task) { unsigned long pc = 0; - if (likely(task && task != current && task->state != TASK_RUNNING)) + if (likely(task && task != current && !task_is_running(task))) walk_stackframe(task, NULL, save_wchan, &pc); return pc; } diff --git a/arch/s390/include/asm/preempt.h b/arch/s390/include/asm/preempt.h index b49e0492842c..23ff51be7e29 100644 --- a/arch/s390/include/asm/preempt.h +++ b/arch/s390/include/asm/preempt.h @@ -32,7 +32,7 @@ static inline void preempt_count_set(int pc) #define init_task_preempt_count(p) do { } while (0) #define init_idle_preempt_count(p, cpu) do { \ - S390_lowcore.preempt_count = PREEMPT_ENABLED; \ + S390_lowcore.preempt_count = PREEMPT_DISABLED; \ } while (0) static inline void set_preempt_need_resched(void) @@ -91,7 +91,7 @@ static inline void preempt_count_set(int pc) #define init_task_preempt_count(p) do { } while (0) #define init_idle_preempt_count(p, cpu) do { \ - S390_lowcore.preempt_count = PREEMPT_ENABLED; \ + S390_lowcore.preempt_count = PREEMPT_DISABLED; \ } while (0) static inline void set_preempt_need_resched(void) diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index e20bed1ed34a..7ae5dde9c54d 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -180,7 +180,7 @@ unsigned long get_wchan(struct task_struct *p) struct unwind_state state; unsigned long ip = 0; - if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) + if (!p || p == current || task_is_running(p) || !task_stack_page(p)) return 0; if (!try_get_task_stack(p)) diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 2fec2b80d35d..111909aeb8d2 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -878,7 +878,6 @@ static void smp_init_secondary(void) restore_access_regs(S390_lowcore.access_regs_save_area); cpu_init(); rcu_cpu_starting(cpu); - preempt_disable(); init_cpu_timer(); vtime_init(); vdso_getcpu_init(); diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 826d01777361..8ae3dc5783fd 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -702,7 +702,7 @@ static void pfault_interrupt(struct ext_code ext_code, * interrupt since it must be a leftover of a PFAULT * CANCEL operation which didn't remove all pending * completion interrupts. */ - if (tsk->state == TASK_RUNNING) + if (task_is_running(tsk)) tsk->thread.pfault_wait = -1; } } else { diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c index 1aa508eb0823..717de05c81f4 100644 --- a/arch/sh/kernel/process_32.c +++ b/arch/sh/kernel/process_32.c @@ -186,7 +186,7 @@ unsigned long get_wchan(struct task_struct *p) { unsigned long pc; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; /* diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 372acdc9033e..65924d9ec245 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -186,8 +186,6 @@ asmlinkage void start_secondary(void) per_cpu_trap_init(); - preempt_disable(); - notify_cpu_starting(cpu); local_irq_enable(); diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index 3b9794978e5b..93983d6d431d 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -376,8 +376,7 @@ unsigned long get_wchan(struct task_struct *task) struct reg_window32 *rw; int count = 0; - if (!task || task == current || - task->state == TASK_RUNNING) + if (!task || task == current || task_is_running(task)) goto out; fp = task_thread_info(task)->ksp + bias; diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index 7afd0a859a78..d33c58a58d4f 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -674,8 +674,7 @@ unsigned long get_wchan(struct task_struct *task) unsigned long ret = 0; int count = 0; - if (!task || task == current || - task->state == TASK_RUNNING) + if (!task || task == current || task_is_running(task)) goto out; tp = task_thread_info(task); diff --git a/arch/sparc/kernel/smp_32.c b/arch/sparc/kernel/smp_32.c index 50c127ab46d5..22b148e5a5f8 100644 --- a/arch/sparc/kernel/smp_32.c +++ b/arch/sparc/kernel/smp_32.c @@ -348,7 +348,6 @@ static void sparc_start_secondary(void *arg) */ arch_cpu_pre_starting(arg); - preempt_disable(); cpu = smp_processor_id(); notify_cpu_starting(cpu); diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index e38d8bf454e8..ae5faa1d989d 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -138,9 +138,6 @@ void smp_callin(void) set_cpu_online(cpuid, true); - /* idle thread is expected to have preempt disabled */ - preempt_disable(); - local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index c5011064b5dd..457a38db368b 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -369,7 +369,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long stack_page, sp, ip; bool seen_sched = 0; - if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) + if ((p == NULL) || (p == current) || task_is_running(p)) return 0; stack_page = (unsigned long) task_stack_page(p); diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index f8cb8af4de5c..fe5efbcba824 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -44,7 +44,7 @@ static __always_inline void preempt_count_set(int pc) #define init_task_preempt_count(p) do { } while (0) #define init_idle_preempt_count(p, cpu) do { \ - per_cpu(__preempt_count, (cpu)) = PREEMPT_ENABLED; \ + per_cpu(__preempt_count, (cpu)) = PREEMPT_DISABLED; \ } while (0) /* diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 5e1f38179f49..e52b208b4641 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -931,7 +931,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long start, bottom, top, sp, fp, ip, ret = 0; int count = 0; - if (p == current || p->state == TASK_RUNNING) + if (p == current || task_is_running(p)) return 0; if (!try_get_task_stack(p)) @@ -975,7 +975,7 @@ unsigned long get_wchan(struct task_struct *p) goto out; } fp = READ_ONCE_NOCHECK(*(unsigned long *)fp); - } while (count++ < 16 && p->state != TASK_RUNNING); + } while (count++ < 16 && !task_is_running(p)); out: put_task_stack(p); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 7770245cc7fa..ec2d64aa2163 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -236,7 +236,6 @@ static void notrace start_secondary(void *unused) cpu_init(); rcu_cpu_starting(raw_smp_processor_id()); x86_cpuinit.early_percpu_clock_init(); - preempt_disable(); smp_callin(); enable_start_cpu0 = 0; diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index f6b93a35ce14..fb8efb387aff 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -22,8 +22,6 @@ config KVM tristate "Kernel-based Virtual Machine (KVM) support" depends on HAVE_KVM depends on HIGH_RES_TIMERS - # for TASKSTATS/TASK_DELAY_ACCT: - depends on NET && MULTIUSER depends on X86_LOCAL_APIC select PREEMPT_NOTIFIERS select MMU_NOTIFIER @@ -36,8 +34,7 @@ config KVM select KVM_ASYNC_PF select USER_RETURN_NOTIFIER select KVM_MMIO - select TASKSTATS - select TASK_DELAY_ACCT + select SCHED_INFO select PERF_EVENTS select HAVE_KVM_MSI select HAVE_KVM_CPU_RELAX_INTERCEPT diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c index 9534ef515d74..060165340612 100644 --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -304,7 +304,7 @@ unsigned long get_wchan(struct task_struct *p) unsigned long stack_page = (unsigned long) task_stack_page(p); int count = 0; - if (!p || p == current || p->state == TASK_RUNNING) + if (!p || p == current || task_is_running(p)) return 0; sp = p->thread.sp; diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c index cd85a7a2722b..1254da07ead1 100644 --- a/arch/xtensa/kernel/smp.c +++ b/arch/xtensa/kernel/smp.c @@ -145,7 +145,6 @@ void secondary_start_kernel(void) cpumask_set_cpu(cpu, mm_cpumask(mm)); enter_lazy_tlb(mm, current); - preempt_disable(); trace_hardirqs_off(); calibrate_delay(); diff --git a/block/blk-mq.c b/block/blk-mq.c index c86c01bfecdb..e41edae97487 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3886,7 +3886,7 @@ static bool blk_mq_poll_hybrid(struct request_queue *q, int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) { struct blk_mq_hw_ctx *hctx; - long state; + unsigned int state; if (!blk_qc_t_valid(cookie) || !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) @@ -3910,7 +3910,7 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) hctx->poll_considered++; - state = current->state; + state = get_current_state(); do { int ret; @@ -3926,7 +3926,7 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) if (signal_pending_state(state, current)) __set_current_state(TASK_RUNNING); - if (current->state == TASK_RUNNING) + if (task_is_running(current)) return 1; if (ret < 0 || !spin) break; diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index c3aa8d6ccee3..2e5670446991 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -117,7 +117,7 @@ struct menu_device { int interval_ptr; }; -static inline int which_bucket(u64 duration_ns, unsigned long nr_iowaiters) +static inline int which_bucket(u64 duration_ns, unsigned int nr_iowaiters) { int bucket = 0; @@ -150,7 +150,7 @@ static inline int which_bucket(u64 duration_ns, unsigned long nr_iowaiters) * to be, the higher this multiplier, and thus the higher * the barrier to go to an expensive C state. */ -static inline int performance_multiplier(unsigned long nr_iowaiters) +static inline int performance_multiplier(unsigned int nr_iowaiters) { /* for IO wait tasks (per cpu!) we add 10x each */ return 1 + 10 * nr_iowaiters; @@ -270,7 +270,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, unsigned int predicted_us; u64 predicted_ns; u64 interactivity_req; - unsigned long nr_iowaiters; + unsigned int nr_iowaiters; ktime_t delta, delta_tick; int i, idx; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ca2aedd8ee7d..190e714cb565 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2328,7 +2328,7 @@ static bool md_in_flight_bios(struct mapped_device *md) return sum != 0; } -static int dm_wait_for_bios_completion(struct mapped_device *md, long task_state) +static int dm_wait_for_bios_completion(struct mapped_device *md, unsigned int task_state) { int r = 0; DEFINE_WAIT(wait); @@ -2351,7 +2351,7 @@ static int dm_wait_for_bios_completion(struct mapped_device *md, long task_state return r; } -static int dm_wait_for_completion(struct mapped_device *md, long task_state) +static int dm_wait_for_completion(struct mapped_device *md, unsigned int task_state) { int r = 0; @@ -2478,7 +2478,7 @@ static void unlock_fs(struct mapped_device *md) * are being added to md->deferred list. */ static int __dm_suspend(struct mapped_device *md, struct dm_table *map, - unsigned suspend_flags, long task_state, + unsigned suspend_flags, unsigned int task_state, int dmf_suspended_flag) { bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG; diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c index ab9b02574a15..0a6b8112b535 100644 --- a/drivers/net/ethernet/qualcomm/qca_spi.c +++ b/drivers/net/ethernet/qualcomm/qca_spi.c @@ -653,8 +653,7 @@ qcaspi_intr_handler(int irq, void *data) struct qcaspi *qca = data; qca->intr_req++; - if (qca->spi_thread && - qca->spi_thread->state != TASK_RUNNING) + if (qca->spi_thread) wake_up_process(qca->spi_thread); return IRQ_HANDLED; @@ -777,8 +776,7 @@ qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev) netif_trans_update(dev); - if (qca->spi_thread && - qca->spi_thread->state != TASK_RUNNING) + if (qca->spi_thread) wake_up_process(qca->spi_thread); return NETDEV_TX_OK; diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c index eeb4e4b76c0b..43b1ae8a7789 100644 --- a/drivers/thermal/cpufreq_cooling.c +++ b/drivers/thermal/cpufreq_cooling.c @@ -478,7 +478,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency); if (ret >= 0) { cpufreq_cdev->cpufreq_state = state; - cpus = cpufreq_cdev->policy->cpus; + cpus = cpufreq_cdev->policy->related_cpus; max_capacity = arch_scale_cpu_capacity(cpumask_first(cpus)); capacity = frequency * max_capacity; capacity /= cpufreq_cdev->policy->cpuinfo.max_freq; diff --git a/drivers/usb/gadget/udc/max3420_udc.c b/drivers/usb/gadget/udc/max3420_udc.c index 35179543c327..34f4db554977 100644 --- a/drivers/usb/gadget/udc/max3420_udc.c +++ b/drivers/usb/gadget/udc/max3420_udc.c @@ -509,8 +509,7 @@ static irqreturn_t max3420_vbus_handler(int irq, void *dev_id) ? USB_STATE_POWERED : USB_STATE_NOTATTACHED); spin_unlock_irqrestore(&udc->lock, flags); - if (udc->thread_task && - udc->thread_task->state != TASK_RUNNING) + if (udc->thread_task) wake_up_process(udc->thread_task); return IRQ_HANDLED; @@ -529,8 +528,7 @@ static irqreturn_t max3420_irq_handler(int irq, void *dev_id) } spin_unlock_irqrestore(&udc->lock, flags); - if (udc->thread_task && - udc->thread_task->state != TASK_RUNNING) + if (udc->thread_task) wake_up_process(udc->thread_task); return IRQ_HANDLED; @@ -1093,8 +1091,7 @@ static int max3420_wakeup(struct usb_gadget *gadget) spin_unlock_irqrestore(&udc->lock, flags); - if (udc->thread_task && - udc->thread_task->state != TASK_RUNNING) + if (udc->thread_task) wake_up_process(udc->thread_task); return ret; } @@ -1117,8 +1114,7 @@ static int max3420_udc_start(struct usb_gadget *gadget, udc->todo |= UDC_START; spin_unlock_irqrestore(&udc->lock, flags); - if (udc->thread_task && - udc->thread_task->state != TASK_RUNNING) + if (udc->thread_task) wake_up_process(udc->thread_task); return 0; @@ -1137,8 +1133,7 @@ static int max3420_udc_stop(struct usb_gadget *gadget) udc->todo |= UDC_START; spin_unlock_irqrestore(&udc->lock, flags); - if (udc->thread_task && - udc->thread_task->state != TASK_RUNNING) + if (udc->thread_task) wake_up_process(udc->thread_task); return 0; diff --git a/drivers/usb/host/max3421-hcd.c b/drivers/usb/host/max3421-hcd.c index afd9174d83b1..e7a8e0609853 100644 --- a/drivers/usb/host/max3421-hcd.c +++ b/drivers/usb/host/max3421-hcd.c @@ -1169,8 +1169,7 @@ max3421_irq_handler(int irq, void *dev_id) struct spi_device *spi = to_spi_device(hcd->self.controller); struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); - if (max3421_hcd->spi_thread && - max3421_hcd->spi_thread->state != TASK_RUNNING) + if (max3421_hcd->spi_thread) wake_up_process(max3421_hcd->spi_thread); if (!test_and_set_bit(ENABLE_IRQ, &max3421_hcd->todo)) disable_irq_nosync(spi->irq); diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 187b3f2b9202..3d73cbb439fa 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1537,7 +1537,8 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, { const struct cred *cred; unsigned int i, len; - + unsigned int state; + /* first copy the parameters from user space */ memset(psinfo, 0, sizeof(struct elf_prpsinfo)); @@ -1559,7 +1560,8 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, psinfo->pr_pgrp = task_pgrp_vnr(p); psinfo->pr_sid = task_session_vnr(p); - i = p->state ? ffz(~p->state) + 1 : 0; + state = READ_ONCE(p->__state); + i = state ? ffz(~state) + 1 : 0; psinfo->pr_state = i; psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; psinfo->pr_zomb = psinfo->pr_sname == 'Z'; @@ -1571,7 +1573,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); rcu_read_unlock(); strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); - + return 0; } diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 2c99b102c860..ab9c31ddffda 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1331,6 +1331,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, { const struct cred *cred; unsigned int i, len; + unsigned int state; /* first copy the parameters from user space */ memset(psinfo, 0, sizeof(struct elf_prpsinfo)); @@ -1353,7 +1354,8 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, psinfo->pr_pgrp = task_pgrp_vnr(p); psinfo->pr_sid = task_session_vnr(p); - i = p->state ? ffz(~p->state) + 1 : 0; + state = READ_ONCE(p->__state); + i = state ? ffz(~state) + 1 : 0; psinfo->pr_state = i; psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; psinfo->pr_zomb = psinfo->pr_sname == 'Z'; diff --git a/fs/proc/loadavg.c b/fs/proc/loadavg.c index 8468baee951d..f32878d9a39f 100644 --- a/fs/proc/loadavg.c +++ b/fs/proc/loadavg.c @@ -16,7 +16,7 @@ static int loadavg_proc_show(struct seq_file *m, void *v) get_avenrun(avnrun, FIXED_1/200, 0); - seq_printf(m, "%lu.%02lu %lu.%02lu %lu.%02lu %ld/%d %d\n", + seq_printf(m, "%lu.%02lu %lu.%02lu %lu.%02lu %u/%d %d\n", LOAD_INT(avnrun[0]), LOAD_FRAC(avnrun[0]), LOAD_INT(avnrun[1]), LOAD_FRAC(avnrun[1]), LOAD_INT(avnrun[2]), LOAD_FRAC(avnrun[2]), diff --git a/fs/proc/stat.c b/fs/proc/stat.c index f25e8531fd27..6561a06ef905 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -200,8 +200,8 @@ static int show_stat(struct seq_file *p, void *v) "\nctxt %llu\n" "btime %llu\n" "processes %lu\n" - "procs_running %lu\n" - "procs_blocked %lu\n", + "procs_running %u\n" + "procs_blocked %u\n", nr_context_switches(), (unsigned long long)boottime.tv_sec, total_forks, diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 14f92285d04f..dd7a6c62b56f 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -337,7 +337,7 @@ out: return ret; } -static inline long userfaultfd_get_blocking_state(unsigned int flags) +static inline unsigned int userfaultfd_get_blocking_state(unsigned int flags) { if (flags & FAULT_FLAG_INTERRUPTIBLE) return TASK_INTERRUPTIBLE; @@ -370,7 +370,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) struct userfaultfd_wait_queue uwq; vm_fault_t ret = VM_FAULT_SIGBUS; bool must_wait; - long blocking_state; + unsigned int blocking_state; /* * We don't do userfault handling for the final child pid update. diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index d683f5e6d791..b4d43a4af5f7 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -29,7 +29,7 @@ static __always_inline void preempt_count_set(int pc) } while (0) #define init_idle_preempt_count(p, cpu) do { \ - task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ } while (0) static __always_inline void set_preempt_need_resched(void) diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 21651f946751..af7e6eb50283 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -58,16 +58,22 @@ struct task_delay_info { #include <linux/sched.h> #include <linux/slab.h> +#include <linux/jump_label.h> #ifdef CONFIG_TASK_DELAY_ACCT +DECLARE_STATIC_KEY_FALSE(delayacct_key); extern int delayacct_on; /* Delay accounting turned on/off */ extern struct kmem_cache *delayacct_cache; extern void delayacct_init(void); + +extern int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos); + extern void __delayacct_tsk_init(struct task_struct *); extern void __delayacct_tsk_exit(struct task_struct *); extern void __delayacct_blkio_start(void); extern void __delayacct_blkio_end(struct task_struct *); -extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); +extern int delayacct_add_tsk(struct taskstats *, struct task_struct *); extern __u64 __delayacct_blkio_ticks(struct task_struct *); extern void __delayacct_freepages_start(void); extern void __delayacct_freepages_end(void); @@ -114,6 +120,9 @@ static inline void delayacct_tsk_free(struct task_struct *tsk) static inline void delayacct_blkio_start(void) { + if (!static_branch_unlikely(&delayacct_key)) + return; + delayacct_set_flag(current, DELAYACCT_PF_BLKIO); if (current->delays) __delayacct_blkio_start(); @@ -121,19 +130,14 @@ static inline void delayacct_blkio_start(void) static inline void delayacct_blkio_end(struct task_struct *p) { + if (!static_branch_unlikely(&delayacct_key)) + return; + if (p->delays) __delayacct_blkio_end(p); delayacct_clear_flag(p, DELAYACCT_PF_BLKIO); } -static inline int delayacct_add_tsk(struct taskstats *d, - struct task_struct *tsk) -{ - if (!delayacct_on || !tsk->delays) - return 0; - return __delayacct_add_tsk(d, tsk); -} - static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) { if (tsk->delays) diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index 757fc60658fa..3f221dbf5f95 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -91,6 +91,8 @@ void em_dev_unregister_perf_domain(struct device *dev); * @pd : performance domain for which energy has to be estimated * @max_util : highest utilization among CPUs of the domain * @sum_util : sum of the utilization of all CPUs in the domain + * @allowed_cpu_cap : maximum allowed CPU capacity for the @pd, which + might reflect reduced frequency (due to thermal) * * This function must be used only for CPU devices. There is no validation, * i.e. if the EM is a CPU type and has cpumask allocated. It is called from @@ -100,7 +102,8 @@ void em_dev_unregister_perf_domain(struct device *dev); * a capacity state satisfying the max utilization of the domain. */ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, - unsigned long max_util, unsigned long sum_util) + unsigned long max_util, unsigned long sum_util, + unsigned long allowed_cpu_cap) { unsigned long freq, scale_cpu; struct em_perf_state *ps; @@ -112,11 +115,17 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, /* * In order to predict the performance state, map the utilization of * the most utilized CPU of the performance domain to a requested - * frequency, like schedutil. + * frequency, like schedutil. Take also into account that the real + * frequency might be set lower (due to thermal capping). Thus, clamp + * max utilization to the allowed CPU capacity before calculating + * effective frequency. */ cpu = cpumask_first(to_cpumask(pd->cpus)); scale_cpu = arch_scale_cpu_capacity(cpu); ps = &pd->table[pd->nr_perf_states - 1]; + + max_util = map_util_perf(max_util); + max_util = min(max_util, allowed_cpu_cap); freq = map_util_freq(max_util, ps->frequency, scale_cpu); /* @@ -209,7 +218,8 @@ static inline struct em_perf_domain *em_pd_get(struct device *dev) return NULL; } static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, - unsigned long max_util, unsigned long sum_util) + unsigned long max_util, unsigned long sum_util, + unsigned long allowed_cpu_cap) { return 0; } diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 2484ed97e72f..d9133d6db308 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -33,6 +33,8 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), unsigned int cpu, const char *namefmt); +void set_kthread_struct(struct task_struct *p); + void kthread_set_per_cpu(struct task_struct *k, int cpu); bool kthread_is_per_cpu(struct task_struct *k); diff --git a/include/linux/sched.h b/include/linux/sched.h index 32813c345115..31aaf9d7b3e9 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -113,11 +113,13 @@ struct task_group; __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ TASK_PARKED) -#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0) +#define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) -#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0) +#define task_is_traced(task) ((READ_ONCE(task->__state) & __TASK_TRACED) != 0) -#define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0) +#define task_is_stopped(task) ((READ_ONCE(task->__state) & __TASK_STOPPED) != 0) + +#define task_is_stopped_or_traced(task) ((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0) #ifdef CONFIG_DEBUG_ATOMIC_SLEEP @@ -132,14 +134,14 @@ struct task_group; do { \ WARN_ON_ONCE(is_special_task_state(state_value));\ current->task_state_change = _THIS_IP_; \ - current->state = (state_value); \ + WRITE_ONCE(current->__state, (state_value)); \ } while (0) #define set_current_state(state_value) \ do { \ WARN_ON_ONCE(is_special_task_state(state_value));\ current->task_state_change = _THIS_IP_; \ - smp_store_mb(current->state, (state_value)); \ + smp_store_mb(current->__state, (state_value)); \ } while (0) #define set_special_state(state_value) \ @@ -148,7 +150,7 @@ struct task_group; WARN_ON_ONCE(!is_special_task_state(state_value)); \ raw_spin_lock_irqsave(¤t->pi_lock, flags); \ current->task_state_change = _THIS_IP_; \ - current->state = (state_value); \ + WRITE_ONCE(current->__state, (state_value)); \ raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ } while (0) #else @@ -190,10 +192,10 @@ struct task_group; * Also see the comments of try_to_wake_up(). */ #define __set_current_state(state_value) \ - current->state = (state_value) + WRITE_ONCE(current->__state, (state_value)) #define set_current_state(state_value) \ - smp_store_mb(current->state, (state_value)) + smp_store_mb(current->__state, (state_value)) /* * set_special_state() should be used for those states when the blocking task @@ -205,12 +207,14 @@ struct task_group; do { \ unsigned long flags; /* may shadow */ \ raw_spin_lock_irqsave(¤t->pi_lock, flags); \ - current->state = (state_value); \ + WRITE_ONCE(current->__state, (state_value)); \ raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ } while (0) #endif +#define get_current_state() READ_ONCE(current->__state) + /* Task command name length: */ #define TASK_COMM_LEN 16 @@ -662,8 +666,7 @@ struct task_struct { */ struct thread_info thread_info; #endif - /* -1 unrunnable, 0 runnable, >0 stopped: */ - volatile long state; + unsigned int __state; /* * This begins the randomizable portion of task_struct. Only @@ -708,10 +711,17 @@ struct task_struct { const struct sched_class *sched_class; struct sched_entity se; struct sched_rt_entity rt; + struct sched_dl_entity dl; + +#ifdef CONFIG_SCHED_CORE + struct rb_node core_node; + unsigned long core_cookie; + unsigned int core_occupation; +#endif + #ifdef CONFIG_CGROUP_SCHED struct task_group *sched_task_group; #endif - struct sched_dl_entity dl; #ifdef CONFIG_UCLAMP_TASK /* @@ -1520,7 +1530,7 @@ static inline pid_t task_pgrp_nr(struct task_struct *tsk) static inline unsigned int task_state_index(struct task_struct *tsk) { - unsigned int tsk_state = READ_ONCE(tsk->state); + unsigned int tsk_state = READ_ONCE(tsk->__state); unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT; BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); @@ -1828,10 +1838,10 @@ static __always_inline void scheduler_ipi(void) */ preempt_fold_need_resched(); } -extern unsigned long wait_task_inactive(struct task_struct *, long match_state); +extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); #else static inline void scheduler_ipi(void) { } -static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state) +static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) { return 1; } @@ -2179,4 +2189,14 @@ int sched_trace_rq_nr_running(struct rq *rq); const struct cpumask *sched_trace_rd_span(struct root_domain *rd); +#ifdef CONFIG_SCHED_CORE +extern void sched_core_free(struct task_struct *tsk); +extern void sched_core_fork(struct task_struct *p); +extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, + unsigned long uaddr); +#else +static inline void sched_core_free(struct task_struct *tsk) { } +static inline void sched_core_fork(struct task_struct *p) { } +#endif + #endif diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h index 6205578ab6ee..bdd31ab93bc5 100644 --- a/include/linux/sched/cpufreq.h +++ b/include/linux/sched/cpufreq.h @@ -26,7 +26,7 @@ bool cpufreq_this_cpu_can_update(struct cpufreq_policy *policy); static inline unsigned long map_util_freq(unsigned long util, unsigned long freq, unsigned long cap) { - return (freq + (freq >> 2)) * util / cap; + return freq * util / cap; } static inline unsigned long map_util_perf(unsigned long util) diff --git a/include/linux/sched/debug.h b/include/linux/sched/debug.h index ae51f4529fc9..b5035afa2396 100644 --- a/include/linux/sched/debug.h +++ b/include/linux/sched/debug.h @@ -14,7 +14,7 @@ extern void dump_cpu_task(int cpu); /* * Only dump TASK_* tasks. (0 for all tasks) */ -extern void show_state_filter(unsigned long state_filter); +extern void show_state_filter(unsigned int state_filter); static inline void show_state(void) { diff --git a/include/linux/sched/sd_flags.h b/include/linux/sched/sd_flags.h index 34b21e971d77..57bde66d95f7 100644 --- a/include/linux/sched/sd_flags.h +++ b/include/linux/sched/sd_flags.h @@ -91,6 +91,16 @@ SD_FLAG(SD_WAKE_AFFINE, SDF_SHARED_CHILD) SD_FLAG(SD_ASYM_CPUCAPACITY, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) /* + * Domain members have different CPU capacities spanning all unique CPU + * capacity values. + * + * SHARED_PARENT: Set from the topmost domain down to the first domain where + * all available CPU capacities are visible + * NEEDS_GROUPS: Per-CPU capacity is asymmetric between groups. + */ +SD_FLAG(SD_ASYM_CPUCAPACITY_FULL, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) + +/* * Domain members share CPU capacity (i.e. SMT) * * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 7f4278fa21fe..c9cf678c347d 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -382,7 +382,7 @@ static inline int fatal_signal_pending(struct task_struct *p) return task_sigpending(p) && __fatal_signal_pending(p); } -static inline int signal_pending_state(long state, struct task_struct *p) +static inline int signal_pending_state(unsigned int state, struct task_struct *p) { if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) return 0; diff --git a/include/linux/sched/stat.h b/include/linux/sched/stat.h index 568286411b43..0108a38bb64d 100644 --- a/include/linux/sched/stat.h +++ b/include/linux/sched/stat.h @@ -3,6 +3,7 @@ #define _LINUX_SCHED_STAT_H #include <linux/percpu.h> +#include <linux/kconfig.h> /* * Various counters maintained by the scheduler and fork(), @@ -16,21 +17,14 @@ extern unsigned long total_forks; extern int nr_threads; DECLARE_PER_CPU(unsigned long, process_counts); extern int nr_processes(void); -extern unsigned long nr_running(void); +extern unsigned int nr_running(void); extern bool single_task_running(void); -extern unsigned long nr_iowait(void); -extern unsigned long nr_iowait_cpu(int cpu); +extern unsigned int nr_iowait(void); +extern unsigned int nr_iowait_cpu(int cpu); static inline int sched_info_on(void) { -#ifdef CONFIG_SCHEDSTATS - return 1; -#elif defined(CONFIG_TASK_DELAY_ACCT) - extern int delayacct_on; - return delayacct_on; -#else - return 0; -#endif + return IS_ENABLED(CONFIG_SCHED_INFO); } #ifdef CONFIG_SCHEDSTATS diff --git a/include/linux/sched_clock.h b/include/linux/sched_clock.h index 528718e4ed52..835ee87ed792 100644 --- a/include/linux/sched_clock.h +++ b/include/linux/sched_clock.h @@ -14,7 +14,7 @@ * @sched_clock_mask: Bitmask for two's complement subtraction of non 64bit * clocks. * @read_sched_clock: Current clock source (or dummy source when suspended). - * @mult: Multipler for scaled math conversion. + * @mult: Multiplier for scaled math conversion. * @shift: Shift value for scaled math conversion. * * Care must be taken when updating this structure; it is read by diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index 18a9f59dc067..967d9c55323d 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -259,4 +259,12 @@ struct prctl_mm_map { #define PR_PAC_SET_ENABLED_KEYS 60 #define PR_PAC_GET_ENABLED_KEYS 61 +/* Request the scheduler to share a core */ +#define PR_SCHED_CORE 62 +# define PR_SCHED_CORE_GET 0 +# define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */ +# define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */ +# define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */ +# define PR_SCHED_CORE_MAX 4 + #endif /* _LINUX_PRCTL_H */ diff --git a/init/init_task.c b/init/init_task.c index 8b08c2e19cbb..562f2ef8d157 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -71,7 +71,7 @@ struct task_struct init_task .thread_info = INIT_THREAD_INFO(init_task), .stack_refcount = REFCOUNT_INIT(1), #endif - .state = 0, + .__state = 0, .stack = init_stack, .usage = REFCOUNT_INIT(2), .flags = PF_KTHREAD, diff --git a/init/main.c b/init/main.c index e9c42a183e33..359358500e54 100644 --- a/init/main.c +++ b/init/main.c @@ -692,6 +692,7 @@ noinline void __ref rest_init(void) */ rcu_read_lock(); tsk = find_task_by_pid_ns(pid, &init_pid_ns); + tsk->flags |= PF_NO_SETAFFINITY; set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); rcu_read_unlock(); @@ -941,11 +942,7 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) * time - but meanwhile we still have a functioning scheduler. */ sched_init(); - /* - * Disable preemption - early bootup scheduling is extremely - * fragile until we cpu_idle() for the first time. - */ - preempt_disable(); + if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n")) local_irq_disable(); @@ -1444,6 +1441,11 @@ static int __ref kernel_init(void *unused) { int ret; + /* + * Wait until kthreadd is all set-up. + */ + wait_for_completion(&kthreadd_done); + kernel_init_freeable(); /* need to finish all async __init code before freeing the memory */ async_synchronize_full(); @@ -1524,11 +1526,6 @@ void __init console_on_rootfs(void) static noinline void __init kernel_init_freeable(void) { - /* - * Wait until kthreadd is all set-up. - */ - wait_for_completion(&kthreadd_done); - /* Now the scheduler is fully set up and can do blocking allocations */ gfp_allowed_mask = __GFP_BITS_MASK; diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 416017301660..bd7c4147b9a8 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -99,3 +99,23 @@ config PREEMPT_DYNAMIC Interesting if you want the same pre-built kernel should be used for both Server and Desktop workloads. + +config SCHED_CORE + bool "Core Scheduling for SMT" + default y + depends on SCHED_SMT + help + This option permits Core Scheduling, a means of coordinated task + selection across SMT siblings. When enabled -- see + prctl(PR_SCHED_CORE) -- task selection ensures that all SMT siblings + will execute a task from the same 'core group', forcing idle when no + matching task is found. + + Use of this feature includes: + - mitigation of some (not all) SMT side channels; + - limiting SMT interference to improve determinism and/or performance. + + SCHED_CORE is default enabled when SCHED_SMT is enabled -- when + unused there should be no impact on performance. + + diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 1f274d7fc934..ee93b6e89587 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -713,7 +713,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) css_task_iter_start(&cgrp->self, 0, &it); while ((tsk = css_task_iter_next(&it))) { - switch (tsk->state) { + switch (READ_ONCE(tsk->__state)) { case TASK_RUNNING: stats->nr_running++; break; diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c index 91bb666d7c03..9f50d22d68e6 100644 --- a/kernel/debug/kdb/kdb_support.c +++ b/kernel/debug/kdb/kdb_support.c @@ -609,23 +609,25 @@ unsigned long kdb_task_state_string(const char *s) */ char kdb_task_state_char (const struct task_struct *p) { - int cpu; - char state; + unsigned int p_state; unsigned long tmp; + char state; + int cpu; if (!p || copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long))) return 'E'; cpu = kdb_process_cpu(p); - state = (p->state == 0) ? 'R' : - (p->state < 0) ? 'U' : - (p->state & TASK_UNINTERRUPTIBLE) ? 'D' : - (p->state & TASK_STOPPED) ? 'T' : - (p->state & TASK_TRACED) ? 'C' : + p_state = READ_ONCE(p->__state); + state = (p_state == 0) ? 'R' : + (p_state < 0) ? 'U' : + (p_state & TASK_UNINTERRUPTIBLE) ? 'D' : + (p_state & TASK_STOPPED) ? 'T' : + (p_state & TASK_TRACED) ? 'C' : (p->exit_state & EXIT_ZOMBIE) ? 'Z' : (p->exit_state & EXIT_DEAD) ? 'E' : - (p->state & TASK_INTERRUPTIBLE) ? 'S' : '?'; + (p_state & TASK_INTERRUPTIBLE) ? 'S' : '?'; if (is_idle_task(p)) { /* Idle task. Is it really idle, apart from the kdb * interrupt? */ diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 27725754ac99..51530d5b15a8 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -7,30 +7,64 @@ #include <linux/sched.h> #include <linux/sched/task.h> #include <linux/sched/cputime.h> +#include <linux/sched/clock.h> #include <linux/slab.h> #include <linux/taskstats.h> -#include <linux/time.h> #include <linux/sysctl.h> #include <linux/delayacct.h> #include <linux/module.h> -int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ -EXPORT_SYMBOL_GPL(delayacct_on); +DEFINE_STATIC_KEY_FALSE(delayacct_key); +int delayacct_on __read_mostly; /* Delay accounting turned on/off */ struct kmem_cache *delayacct_cache; -static int __init delayacct_setup_disable(char *str) +static void set_delayacct(bool enabled) { - delayacct_on = 0; + if (enabled) { + static_branch_enable(&delayacct_key); + delayacct_on = 1; + } else { + delayacct_on = 0; + static_branch_disable(&delayacct_key); + } +} + +static int __init delayacct_setup_enable(char *str) +{ + delayacct_on = 1; return 1; } -__setup("nodelayacct", delayacct_setup_disable); +__setup("delayacct", delayacct_setup_enable); void delayacct_init(void) { delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT); delayacct_tsk_init(&init_task); + set_delayacct(delayacct_on); } +#ifdef CONFIG_PROC_SYSCTL +int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + int state = delayacct_on; + struct ctl_table t; + int err; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + t = *table; + t.data = &state; + err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); + if (err < 0) + return err; + if (write) + set_delayacct(state); + return err; +} +#endif + void __delayacct_tsk_init(struct task_struct *tsk) { tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL); @@ -42,10 +76,9 @@ void __delayacct_tsk_init(struct task_struct *tsk) * Finish delay accounting for a statistic using its timestamps (@start), * accumalator (@total) and @count */ -static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total, - u32 *count) +static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total, u32 *count) { - s64 ns = ktime_get_ns() - *start; + s64 ns = local_clock() - *start; unsigned long flags; if (ns > 0) { @@ -58,7 +91,7 @@ static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total, void __delayacct_blkio_start(void) { - current->delays->blkio_start = ktime_get_ns(); + current->delays->blkio_start = local_clock(); } /* @@ -82,7 +115,7 @@ void __delayacct_blkio_end(struct task_struct *p) delayacct_end(&delays->lock, &delays->blkio_start, total, count); } -int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) +int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) { u64 utime, stime, stimescaled, utimescaled; unsigned long long t2, t3; @@ -117,6 +150,9 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) d->cpu_run_virtual_total = (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; + if (!tsk->delays) + return 0; + /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ raw_spin_lock_irqsave(&tsk->delays->lock, flags); @@ -151,21 +187,20 @@ __u64 __delayacct_blkio_ticks(struct task_struct *tsk) void __delayacct_freepages_start(void) { - current->delays->freepages_start = ktime_get_ns(); + current->delays->freepages_start = local_clock(); } void __delayacct_freepages_end(void) { - delayacct_end( - ¤t->delays->lock, - ¤t->delays->freepages_start, - ¤t->delays->freepages_delay, - ¤t->delays->freepages_count); + delayacct_end(¤t->delays->lock, + ¤t->delays->freepages_start, + ¤t->delays->freepages_delay, + ¤t->delays->freepages_count); } void __delayacct_thrashing_start(void) { - current->delays->thrashing_start = ktime_get_ns(); + current->delays->thrashing_start = local_clock(); } void __delayacct_thrashing_end(void) diff --git a/kernel/events/core.c b/kernel/events/core.c index ea0e24040691..4576413b6230 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8690,13 +8690,12 @@ static void perf_event_switch(struct task_struct *task, }, }; - if (!sched_in && task->state == TASK_RUNNING) + if (!sched_in && task->on_rq) { switch_event.event_id.header.misc |= PERF_RECORD_MISC_SWITCH_OUT_PREEMPT; + } - perf_iterate_sb(perf_event_switch_output, - &switch_event, - NULL); + perf_iterate_sb(perf_event_switch_output, &switch_event, NULL); } /* diff --git a/kernel/fork.c b/kernel/fork.c index a070caed5c8e..4820c2aaeb5a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -425,7 +425,7 @@ static int memcg_charge_kernel_stack(struct task_struct *tsk) static void release_task_stack(struct task_struct *tsk) { - if (WARN_ON(tsk->state != TASK_DEAD)) + if (WARN_ON(READ_ONCE(tsk->__state) != TASK_DEAD)) return; /* Better to leak the stack than to free prematurely */ account_kernel_stack(tsk, -1); @@ -742,6 +742,7 @@ void __put_task_struct(struct task_struct *tsk) exit_creds(tsk); delayacct_tsk_free(tsk); put_signal_struct(tsk->signal); + sched_core_free(tsk); if (!profile_handoff_task(tsk)) free_task(tsk); @@ -1999,7 +2000,7 @@ static __latent_entropy struct task_struct *copy_process( goto bad_fork_cleanup_count; delayacct_tsk_init(p); /* Must remain after dup_task_struct() */ - p->flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER | PF_IDLE); + p->flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER | PF_IDLE | PF_NO_SETAFFINITY); p->flags |= PF_FORKNOEXEC; INIT_LIST_HEAD(&p->children); INIT_LIST_HEAD(&p->sibling); @@ -2249,6 +2250,8 @@ static __latent_entropy struct task_struct *copy_process( klp_copy_process(p); + sched_core_fork(p); + spin_lock(¤t->sighand->siglock); /* @@ -2336,6 +2339,7 @@ static __latent_entropy struct task_struct *copy_process( return p; bad_fork_cancel_cgroup: + sched_core_free(p); spin_unlock(¤t->sighand->siglock); write_unlock_irq(&tasklist_lock); cgroup_cancel_fork(p, args); @@ -2387,7 +2391,7 @@ bad_fork_cleanup_count: atomic_dec(&p->cred->user->processes); exit_creds(p); bad_fork_free: - p->state = TASK_DEAD; + WRITE_ONCE(p->__state, TASK_DEAD); put_task_stack(p); delayed_free_task(p); fork_out: @@ -2407,7 +2411,7 @@ static inline void init_idle_pids(struct task_struct *idle) } } -struct task_struct *fork_idle(int cpu) +struct task_struct * __init fork_idle(int cpu) { struct task_struct *task; struct kernel_clone_args args = { diff --git a/kernel/freezer.c b/kernel/freezer.c index dc520f01f99d..45ab36ffd0e7 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -58,7 +58,7 @@ bool __refrigerator(bool check_kthr_stop) /* Hmm, should we be allowed to suspend when there are realtime processes around? */ bool was_frozen = false; - long save = current->state; + unsigned int save = get_current_state(); pr_debug("%s entered refrigerator\n", current->comm); diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 396ebaebea3f..b0ce8b3f3822 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -196,7 +196,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) last_break = jiffies; } /* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */ - if (t->state == TASK_UNINTERRUPTIBLE) + if (READ_ONCE(t->__state) == TASK_UNINTERRUPTIBLE) check_hung_task(t, timeout); } unlock: diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c index 13dce3c664d6..56016e8e7461 100644 --- a/kernel/kcsan/report.c +++ b/kernel/kcsan/report.c @@ -460,7 +460,7 @@ static void set_other_info_task_blocking(unsigned long *flags, * We may be instrumenting a code-path where current->state is already * something other than TASK_RUNNING. */ - const bool is_running = current->state == TASK_RUNNING; + const bool is_running = task_is_running(current); /* * To avoid deadlock in case we are in an interrupt here and this is a * race with a task on the same CPU (KCSAN_INTERRUPT_WATCHER), provide a diff --git a/kernel/kthread.c b/kernel/kthread.c index 0fccf7d0c6a1..6b0a30a944b3 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -68,16 +68,6 @@ enum KTHREAD_BITS { KTHREAD_SHOULD_PARK, }; -static inline void set_kthread_struct(void *kthread) -{ - /* - * We abuse ->set_child_tid to avoid the new member and because it - * can't be wrongly copied by copy_process(). We also rely on fact - * that the caller can't exec, so PF_KTHREAD can't be cleared. - */ - current->set_child_tid = (__force void __user *)kthread; -} - static inline struct kthread *to_kthread(struct task_struct *k) { WARN_ON(!(k->flags & PF_KTHREAD)); @@ -103,6 +93,22 @@ static inline struct kthread *__to_kthread(struct task_struct *p) return kthread; } +void set_kthread_struct(struct task_struct *p) +{ + struct kthread *kthread; + + if (__to_kthread(p)) + return; + + kthread = kzalloc(sizeof(*kthread), GFP_KERNEL); + /* + * We abuse ->set_child_tid to avoid the new member and because it + * can't be wrongly copied by copy_process(). We also rely on fact + * that the caller can't exec, so PF_KTHREAD can't be cleared. + */ + p->set_child_tid = (__force void __user *)kthread; +} + void free_kthread_struct(struct task_struct *k) { struct kthread *kthread; @@ -272,8 +278,8 @@ static int kthread(void *_create) struct kthread *self; int ret; - self = kzalloc(sizeof(*self), GFP_KERNEL); - set_kthread_struct(self); + set_kthread_struct(current); + self = to_kthread(current); /* If user was SIGKILLed, I release the structure. */ done = xchg(&create->done, NULL); @@ -451,7 +457,7 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), } EXPORT_SYMBOL(kthread_create_on_node); -static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, long state) +static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, unsigned int state) { unsigned long flags; @@ -467,7 +473,7 @@ static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mas raw_spin_unlock_irqrestore(&p->pi_lock, flags); } -static void __kthread_bind(struct task_struct *p, unsigned int cpu, long state) +static void __kthread_bind(struct task_struct *p, unsigned int cpu, unsigned int state) { __kthread_bind_mask(p, cpumask_of(cpu), state); } diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 0c0524bfff99..e97d08001437 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -760,7 +760,7 @@ static void lockdep_print_held_locks(struct task_struct *p) * It's not reliable to print a task's held locks if it's not sleeping * and it's not the current task. */ - if (p->state == TASK_RUNNING && p != current) + if (p != current && task_is_running(p)) return; for (i = 0; i < depth; i++) { printk(" #%d: ", i); diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 013e1b08a1bf..d2df5e68b503 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -923,7 +923,7 @@ __ww_mutex_add_waiter(struct mutex_waiter *waiter, * Lock a mutex (possibly interruptible), slowpath: */ static __always_inline int __sched -__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, +__mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclass, struct lockdep_map *nest_lock, unsigned long ip, struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx) { @@ -1098,14 +1098,14 @@ err_early_kill: } static int __sched -__mutex_lock(struct mutex *lock, long state, unsigned int subclass, +__mutex_lock(struct mutex *lock, unsigned int state, unsigned int subclass, struct lockdep_map *nest_lock, unsigned long ip) { return __mutex_lock_common(lock, state, subclass, nest_lock, ip, NULL, false); } static int __sched -__ww_mutex_lock(struct mutex *lock, long state, unsigned int subclass, +__ww_mutex_lock(struct mutex *lock, unsigned int state, unsigned int subclass, struct lockdep_map *nest_lock, unsigned long ip, struct ww_acquire_ctx *ww_ctx) { diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 406818196a9f..b5d9bb5202c6 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1135,7 +1135,7 @@ void __sched rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) * * Must be called with lock->wait_lock held and interrupts disabled */ -static int __sched __rt_mutex_slowlock(struct rt_mutex *lock, int state, +static int __sched __rt_mutex_slowlock(struct rt_mutex *lock, unsigned int state, struct hrtimer_sleeper *timeout, struct rt_mutex_waiter *waiter) { @@ -1190,7 +1190,7 @@ static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock, /* * Slow path lock function: */ -static int __sched rt_mutex_slowlock(struct rt_mutex *lock, int state, +static int __sched rt_mutex_slowlock(struct rt_mutex *lock, unsigned int state, struct hrtimer_sleeper *timeout, enum rtmutex_chainwalk chwalk) { diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 809b0016d344..16bfbb10c74d 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -889,7 +889,7 @@ rwsem_spin_on_owner(struct rw_semaphore *sem) * Wait for the read lock to be granted */ static struct rw_semaphore __sched * -rwsem_down_read_slowpath(struct rw_semaphore *sem, long count, int state) +rwsem_down_read_slowpath(struct rw_semaphore *sem, long count, unsigned int state) { long adjustment = -RWSEM_READER_BIAS; long rcnt = (count >> RWSEM_READER_SHIFT); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 2997ca600d18..f8589bf8d7dc 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -197,7 +197,7 @@ static bool ptrace_freeze_traced(struct task_struct *task) spin_lock_irq(&task->sighand->siglock); if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && !__fatal_signal_pending(task)) { - task->state = __TASK_TRACED; + WRITE_ONCE(task->__state, __TASK_TRACED); ret = true; } spin_unlock_irq(&task->sighand->siglock); @@ -207,7 +207,7 @@ static bool ptrace_freeze_traced(struct task_struct *task) static void ptrace_unfreeze_traced(struct task_struct *task) { - if (task->state != __TASK_TRACED) + if (READ_ONCE(task->__state) != __TASK_TRACED) return; WARN_ON(!task->ptrace || task->parent != current); @@ -217,11 +217,11 @@ static void ptrace_unfreeze_traced(struct task_struct *task) * Recheck state under the lock to close this race. */ spin_lock_irq(&task->sighand->siglock); - if (task->state == __TASK_TRACED) { + if (READ_ONCE(task->__state) == __TASK_TRACED) { if (__fatal_signal_pending(task)) wake_up_state(task, __TASK_TRACED); else - task->state = TASK_TRACED; + WRITE_ONCE(task->__state, TASK_TRACED); } spin_unlock_irq(&task->sighand->siglock); } @@ -256,7 +256,7 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state) */ read_lock(&tasklist_lock); if (child->ptrace && child->parent == current) { - WARN_ON(child->state == __TASK_TRACED); + WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED); /* * child->sighand can't be NULL, release_task() * does ptrace_unlink() before __exit_signal(). @@ -273,7 +273,7 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state) * ptrace_stop() changes ->state back to TASK_RUNNING, * so we should not worry about leaking __TASK_TRACED. */ - WARN_ON(child->state == __TASK_TRACED); + WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED); ret = -ESRCH; } } diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 29d2f4c647d3..194b9c145c40 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1831,10 +1831,10 @@ rcu_torture_stats_print(void) srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq); wtp = READ_ONCE(writer_task); - pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#lx cpu %d\n", + pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", rcu_torture_writer_state_getname(), rcu_torture_writer_state, gp_seq, flags, - wtp == NULL ? ~0UL : wtp->state, + wtp == NULL ? ~0U : wtp->__state, wtp == NULL ? -1 : (int)task_cpu(wtp)); if (!splatted && wtp) { sched_show_task(wtp); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index ad0156b86937..4d6962048c30 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2768,7 +2768,7 @@ EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb); #ifdef CONFIG_SMP static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) { - return tsp && tsp->state == TASK_RUNNING && !tsp->on_cpu ? "!" : ""; + return tsp && task_is_running(tsp) && !tsp->on_cpu ? "!" : ""; } #else // #ifdef CONFIG_SMP static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 59b95cc5cbdf..acb2288063b5 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -460,12 +460,12 @@ static void rcu_check_gp_kthread_starvation(void) if (rcu_is_gp_kthread_starving(&j)) { cpu = gpk ? task_cpu(gpk) : -1; - pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#lx ->cpu=%d\n", + pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x ->cpu=%d\n", rcu_state.name, j, (long)rcu_seq_current(&rcu_state.gp_seq), data_race(rcu_state.gp_flags), gp_state_getname(rcu_state.gp_state), rcu_state.gp_state, - gpk ? gpk->state : ~0, cpu); + gpk ? gpk->__state : ~0, cpu); if (gpk) { pr_err("\tUnless %s kthread gets sufficient CPU time, OOM is now expected behavior.\n", rcu_state.name); pr_err("RCU grace-period kthread stack dump:\n"); @@ -503,12 +503,12 @@ static void rcu_check_gp_kthread_expired_fqs_timer(void) time_after(jiffies, jiffies_fqs + RCU_STALL_MIGHT_MIN) && gpk && !READ_ONCE(gpk->on_rq)) { cpu = task_cpu(gpk); - pr_err("%s kthread timer wakeup didn't happen for %ld jiffies! g%ld f%#x %s(%d) ->state=%#lx\n", + pr_err("%s kthread timer wakeup didn't happen for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x\n", rcu_state.name, (jiffies - jiffies_fqs), (long)rcu_seq_current(&rcu_state.gp_seq), data_race(rcu_state.gp_flags), gp_state_getname(RCU_GP_WAIT_FQS), RCU_GP_WAIT_FQS, - gpk->state); + gpk->__state); pr_err("\tPossible timer handling issue on cpu=%d timer-softirq=%u\n", cpu, kstat_softirqs_cpu(TIMER_SOFTIRQ, cpu)); } @@ -735,9 +735,9 @@ void show_rcu_gp_kthreads(void) ja = j - data_race(rcu_state.gp_activity); jr = j - data_race(rcu_state.gp_req_activity); jw = j - data_race(rcu_state.gp_wake_time); - pr_info("%s: wait state: %s(%d) ->state: %#lx delta ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_flags %#x\n", + pr_info("%s: wait state: %s(%d) ->state: %#x delta ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_flags %#x\n", rcu_state.name, gp_state_getname(rcu_state.gp_state), - rcu_state.gp_state, t ? t->state : 0x1ffffL, + rcu_state.gp_state, t ? t->__state : 0x1ffff, ja, jr, jw, (long)data_race(rcu_state.gp_wake_seq), (long)data_race(rcu_state.gp_seq), (long)data_race(rcu_get_root()->gp_seq_needed), diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 5fc9c9b70862..978fcfca5871 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -36,3 +36,4 @@ obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o obj-$(CONFIG_MEMBARRIER) += membarrier.o obj-$(CONFIG_CPU_ISOLATION) += isolation.o obj-$(CONFIG_PSI) += psi.o +obj-$(CONFIG_SCHED_CORE) += core_sched.o diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4ca80df205ce..4a2a448d8dd4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -84,6 +84,272 @@ unsigned int sysctl_sched_rt_period = 1000000; __read_mostly int scheduler_running; +#ifdef CONFIG_SCHED_CORE + +DEFINE_STATIC_KEY_FALSE(__sched_core_enabled); + +/* kernel prio, less is more */ +static inline int __task_prio(struct task_struct *p) +{ + if (p->sched_class == &stop_sched_class) /* trumps deadline */ + return -2; + + if (rt_prio(p->prio)) /* includes deadline */ + return p->prio; /* [-1, 99] */ + + if (p->sched_class == &idle_sched_class) + return MAX_RT_PRIO + NICE_WIDTH; /* 140 */ + + return MAX_RT_PRIO + MAX_NICE; /* 120, squash fair */ +} + +/* + * l(a,b) + * le(a,b) := !l(b,a) + * g(a,b) := l(b,a) + * ge(a,b) := !l(a,b) + */ + +/* real prio, less is less */ +static inline bool prio_less(struct task_struct *a, struct task_struct *b, bool in_fi) +{ + + int pa = __task_prio(a), pb = __task_prio(b); + + if (-pa < -pb) + return true; + + if (-pb < -pa) + return false; + + if (pa == -1) /* dl_prio() doesn't work because of stop_class above */ + return !dl_time_before(a->dl.deadline, b->dl.deadline); + + if (pa == MAX_RT_PRIO + MAX_NICE) /* fair */ + return cfs_prio_less(a, b, in_fi); + + return false; +} + +static inline bool __sched_core_less(struct task_struct *a, struct task_struct *b) +{ + if (a->core_cookie < b->core_cookie) + return true; + + if (a->core_cookie > b->core_cookie) + return false; + + /* flip prio, so high prio is leftmost */ + if (prio_less(b, a, task_rq(a)->core->core_forceidle)) + return true; + + return false; +} + +#define __node_2_sc(node) rb_entry((node), struct task_struct, core_node) + +static inline bool rb_sched_core_less(struct rb_node *a, const struct rb_node *b) +{ + return __sched_core_less(__node_2_sc(a), __node_2_sc(b)); +} + +static inline int rb_sched_core_cmp(const void *key, const struct rb_node *node) +{ + const struct task_struct *p = __node_2_sc(node); + unsigned long cookie = (unsigned long)key; + + if (cookie < p->core_cookie) + return -1; + + if (cookie > p->core_cookie) + return 1; + + return 0; +} + +void sched_core_enqueue(struct rq *rq, struct task_struct *p) +{ + rq->core->core_task_seq++; + + if (!p->core_cookie) + return; + + rb_add(&p->core_node, &rq->core_tree, rb_sched_core_less); +} + +void sched_core_dequeue(struct rq *rq, struct task_struct *p) +{ + rq->core->core_task_seq++; + + if (!sched_core_enqueued(p)) + return; + + rb_erase(&p->core_node, &rq->core_tree); + RB_CLEAR_NODE(&p->core_node); +} + +/* + * Find left-most (aka, highest priority) task matching @cookie. + */ +static struct task_struct *sched_core_find(struct rq *rq, unsigned long cookie) +{ + struct rb_node *node; + + node = rb_find_first((void *)cookie, &rq->core_tree, rb_sched_core_cmp); + /* + * The idle task always matches any cookie! + */ + if (!node) + return idle_sched_class.pick_task(rq); + + return __node_2_sc(node); +} + +static struct task_struct *sched_core_next(struct task_struct *p, unsigned long cookie) +{ + struct rb_node *node = &p->core_node; + + node = rb_next(node); + if (!node) + return NULL; + + p = container_of(node, struct task_struct, core_node); + if (p->core_cookie != cookie) + return NULL; + + return p; +} + +/* + * Magic required such that: + * + * raw_spin_rq_lock(rq); + * ... + * raw_spin_rq_unlock(rq); + * + * ends up locking and unlocking the _same_ lock, and all CPUs + * always agree on what rq has what lock. + * + * XXX entirely possible to selectively enable cores, don't bother for now. + */ + +static DEFINE_MUTEX(sched_core_mutex); +static atomic_t sched_core_count; +static struct cpumask sched_core_mask; + +static void __sched_core_flip(bool enabled) +{ + int cpu, t, i; + + cpus_read_lock(); + + /* + * Toggle the online cores, one by one. + */ + cpumask_copy(&sched_core_mask, cpu_online_mask); + for_each_cpu(cpu, &sched_core_mask) { + const struct cpumask *smt_mask = cpu_smt_mask(cpu); + + i = 0; + local_irq_disable(); + for_each_cpu(t, smt_mask) { + /* supports up to SMT8 */ + raw_spin_lock_nested(&cpu_rq(t)->__lock, i++); + } + + for_each_cpu(t, smt_mask) + cpu_rq(t)->core_enabled = enabled; + + for_each_cpu(t, smt_mask) + raw_spin_unlock(&cpu_rq(t)->__lock); + local_irq_enable(); + + cpumask_andnot(&sched_core_mask, &sched_core_mask, smt_mask); + } + + /* + * Toggle the offline CPUs. + */ + cpumask_copy(&sched_core_mask, cpu_possible_mask); + cpumask_andnot(&sched_core_mask, &sched_core_mask, cpu_online_mask); + + for_each_cpu(cpu, &sched_core_mask) + cpu_rq(cpu)->core_enabled = enabled; + + cpus_read_unlock(); +} + +static void sched_core_assert_empty(void) +{ + int cpu; + + for_each_possible_cpu(cpu) + WARN_ON_ONCE(!RB_EMPTY_ROOT(&cpu_rq(cpu)->core_tree)); +} + +static void __sched_core_enable(void) +{ + static_branch_enable(&__sched_core_enabled); + /* + * Ensure all previous instances of raw_spin_rq_*lock() have finished + * and future ones will observe !sched_core_disabled(). + */ + synchronize_rcu(); + __sched_core_flip(true); + sched_core_assert_empty(); +} + +static void __sched_core_disable(void) +{ + sched_core_assert_empty(); + __sched_core_flip(false); + static_branch_disable(&__sched_core_enabled); +} + +void sched_core_get(void) +{ + if (atomic_inc_not_zero(&sched_core_count)) + return; + + mutex_lock(&sched_core_mutex); + if (!atomic_read(&sched_core_count)) + __sched_core_enable(); + + smp_mb__before_atomic(); + atomic_inc(&sched_core_count); + mutex_unlock(&sched_core_mutex); +} + +static void __sched_core_put(struct work_struct *work) +{ + if (atomic_dec_and_mutex_lock(&sched_core_count, &sched_core_mutex)) { + __sched_core_disable(); + mutex_unlock(&sched_core_mutex); + } +} + +void sched_core_put(void) +{ + static DECLARE_WORK(_work, __sched_core_put); + + /* + * "There can be only one" + * + * Either this is the last one, or we don't actually need to do any + * 'work'. If it is the last *again*, we rely on + * WORK_STRUCT_PENDING_BIT. + */ + if (!atomic_add_unless(&sched_core_count, -1, 1)) + schedule_work(&_work); +} + +#else /* !CONFIG_SCHED_CORE */ + +static inline void sched_core_enqueue(struct rq *rq, struct task_struct *p) { } +static inline void sched_core_dequeue(struct rq *rq, struct task_struct *p) { } + +#endif /* CONFIG_SCHED_CORE */ + /* * part of the period that we allow rt tasks to run in us. * default: 0.95s @@ -184,6 +450,79 @@ int sysctl_sched_rt_runtime = 950000; * */ +void raw_spin_rq_lock_nested(struct rq *rq, int subclass) +{ + raw_spinlock_t *lock; + + /* Matches synchronize_rcu() in __sched_core_enable() */ + preempt_disable(); + if (sched_core_disabled()) { + raw_spin_lock_nested(&rq->__lock, subclass); + /* preempt_count *MUST* be > 1 */ + preempt_enable_no_resched(); + return; + } + + for (;;) { + lock = __rq_lockp(rq); + raw_spin_lock_nested(lock, subclass); + if (likely(lock == __rq_lockp(rq))) { + /* preempt_count *MUST* be > 1 */ + preempt_enable_no_resched(); + return; + } + raw_spin_unlock(lock); + } +} + +bool raw_spin_rq_trylock(struct rq *rq) +{ + raw_spinlock_t *lock; + bool ret; + + /* Matches synchronize_rcu() in __sched_core_enable() */ + preempt_disable(); + if (sched_core_disabled()) { + ret = raw_spin_trylock(&rq->__lock); + preempt_enable(); + return ret; + } + + for (;;) { + lock = __rq_lockp(rq); + ret = raw_spin_trylock(lock); + if (!ret || (likely(lock == __rq_lockp(rq)))) { + preempt_enable(); + return ret; + } + raw_spin_unlock(lock); + } +} + +void raw_spin_rq_unlock(struct rq *rq) +{ + raw_spin_unlock(rq_lockp(rq)); +} + +#ifdef CONFIG_SMP +/* + * double_rq_lock - safely lock two runqueues + */ +void double_rq_lock(struct rq *rq1, struct rq *rq2) +{ + lockdep_assert_irqs_disabled(); + + if (rq_order_less(rq2, rq1)) + swap(rq1, rq2); + + raw_spin_rq_lock(rq1); + if (__rq_lockp(rq1) == __rq_lockp(rq2)) + return; + + raw_spin_rq_lock_nested(rq2, SINGLE_DEPTH_NESTING); +} +#endif + /* * __task_rq_lock - lock the rq @p resides on. */ @@ -196,12 +535,12 @@ struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) for (;;) { rq = task_rq(p); - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { rq_pin_lock(rq, rf); return rq; } - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); while (unlikely(task_on_rq_migrating(p))) cpu_relax(); @@ -220,7 +559,7 @@ struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) for (;;) { raw_spin_lock_irqsave(&p->pi_lock, rf->flags); rq = task_rq(p); - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); /* * move_queued_task() task_rq_lock() * @@ -242,7 +581,7 @@ struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) rq_pin_lock(rq, rf); return rq; } - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); while (unlikely(task_on_rq_migrating(p))) @@ -312,7 +651,7 @@ void update_rq_clock(struct rq *rq) { s64 delta; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); if (rq->clock_update_flags & RQCF_ACT_SKIP) return; @@ -585,7 +924,6 @@ void wake_up_q(struct wake_q_head *head) struct task_struct *task; task = container_of(node, struct task_struct, wake_q); - BUG_ON(!task); /* Task can safely be re-inserted now: */ node = node->next; task->wake_q.next = NULL; @@ -611,7 +949,7 @@ void resched_curr(struct rq *rq) struct task_struct *curr = rq->curr; int cpu; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); if (test_tsk_need_resched(curr)) return; @@ -635,10 +973,10 @@ void resched_cpu(int cpu) struct rq *rq = cpu_rq(cpu); unsigned long flags; - raw_spin_lock_irqsave(&rq->lock, flags); + raw_spin_rq_lock_irqsave(rq, flags); if (cpu_online(cpu) || cpu == smp_processor_id()) resched_curr(rq); - raw_spin_unlock_irqrestore(&rq->lock, flags); + raw_spin_rq_unlock_irqrestore(rq, flags); } #ifdef CONFIG_SMP @@ -1065,9 +1403,10 @@ static void uclamp_sync_util_min_rt_default(void) static inline struct uclamp_se uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id) { + /* Copy by value as we could modify it */ struct uclamp_se uc_req = p->uclamp_req[clamp_id]; #ifdef CONFIG_UCLAMP_TASK_GROUP - struct uclamp_se uc_max; + unsigned int tg_min, tg_max, value; /* * Tasks in autogroups or root task group will be @@ -1078,9 +1417,11 @@ uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id) if (task_group(p) == &root_task_group) return uc_req; - uc_max = task_group(p)->uclamp[clamp_id]; - if (uc_req.value > uc_max.value || !uc_req.user_defined) - return uc_max; + tg_min = task_group(p)->uclamp[UCLAMP_MIN].value; + tg_max = task_group(p)->uclamp[UCLAMP_MAX].value; + value = uc_req.value; + value = clamp(value, tg_min, tg_max); + uclamp_se_set(&uc_req, value, false); #endif return uc_req; @@ -1137,7 +1478,7 @@ static inline void uclamp_rq_inc_id(struct rq *rq, struct task_struct *p, struct uclamp_se *uc_se = &p->uclamp[clamp_id]; struct uclamp_bucket *bucket; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); /* Update task effective clamp */ p->uclamp[clamp_id] = uclamp_eff_get(p, clamp_id); @@ -1177,7 +1518,7 @@ static inline void uclamp_rq_dec_id(struct rq *rq, struct task_struct *p, unsigned int bkt_clamp; unsigned int rq_clamp; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); /* * If sched_uclamp_used was enabled after task @p was enqueued, @@ -1279,8 +1620,9 @@ static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) } static inline void -uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id) +uclamp_update_active(struct task_struct *p) { + enum uclamp_id clamp_id; struct rq_flags rf; struct rq *rq; @@ -1300,9 +1642,11 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id) * affecting a valid clamp bucket, the next time it's enqueued, * it will already see the updated clamp bucket value. */ - if (p->uclamp[clamp_id].active) { - uclamp_rq_dec_id(rq, p, clamp_id); - uclamp_rq_inc_id(rq, p, clamp_id); + for_each_clamp_id(clamp_id) { + if (p->uclamp[clamp_id].active) { + uclamp_rq_dec_id(rq, p, clamp_id); + uclamp_rq_inc_id(rq, p, clamp_id); + } } task_rq_unlock(rq, p, &rf); @@ -1310,20 +1654,14 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id) #ifdef CONFIG_UCLAMP_TASK_GROUP static inline void -uclamp_update_active_tasks(struct cgroup_subsys_state *css, - unsigned int clamps) +uclamp_update_active_tasks(struct cgroup_subsys_state *css) { - enum uclamp_id clamp_id; struct css_task_iter it; struct task_struct *p; css_task_iter_start(css, 0, &it); - while ((p = css_task_iter_next(&it))) { - for_each_clamp_id(clamp_id) { - if ((0x1 << clamp_id) & clamps) - uclamp_update_active(p, clamp_id); - } - } + while ((p = css_task_iter_next(&it))) + uclamp_update_active(p); css_task_iter_end(&it); } @@ -1596,21 +1934,27 @@ static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) update_rq_clock(rq); if (!(flags & ENQUEUE_RESTORE)) { - sched_info_queued(rq, p); + sched_info_enqueue(rq, p); psi_enqueue(p, flags & ENQUEUE_WAKEUP); } uclamp_rq_inc(rq, p); p->sched_class->enqueue_task(rq, p, flags); + + if (sched_core_enabled(rq)) + sched_core_enqueue(rq, p); } static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags) { + if (sched_core_enabled(rq)) + sched_core_dequeue(rq, p); + if (!(flags & DEQUEUE_NOCLOCK)) update_rq_clock(rq); if (!(flags & DEQUEUE_SAVE)) { - sched_info_dequeued(rq, p); + sched_info_dequeue(rq, p); psi_dequeue(p, flags & DEQUEUE_SLEEP); } @@ -1850,7 +2194,7 @@ static inline bool is_cpu_allowed(struct task_struct *p, int cpu) static struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf, struct task_struct *p, int new_cpu) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); deactivate_task(rq, p, DEQUEUE_NOCLOCK); set_task_cpu(p, new_cpu); @@ -1916,7 +2260,6 @@ static int migration_cpu_stop(void *data) struct migration_arg *arg = data; struct set_affinity_pending *pending = arg->pending; struct task_struct *p = arg->task; - int dest_cpu = arg->dest_cpu; struct rq *rq = this_rq(); bool complete = false; struct rq_flags rf; @@ -1954,19 +2297,15 @@ static int migration_cpu_stop(void *data) if (pending) { p->migration_pending = NULL; complete = true; - } - if (dest_cpu < 0) { if (cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) goto out; - - dest_cpu = cpumask_any_distribute(&p->cpus_mask); } if (task_on_rq_queued(p)) - rq = __migrate_task(rq, &rf, p, dest_cpu); + rq = __migrate_task(rq, &rf, p, arg->dest_cpu); else - p->wake_cpu = dest_cpu; + p->wake_cpu = arg->dest_cpu; /* * XXX __migrate_task() can fail, at which point we might end @@ -2024,7 +2363,7 @@ int push_cpu_stop(void *arg) struct task_struct *p = arg; raw_spin_lock_irq(&p->pi_lock); - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); if (task_rq(p) != rq) goto out_unlock; @@ -2054,7 +2393,7 @@ int push_cpu_stop(void *arg) out_unlock: rq->push_busy = false; - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); raw_spin_unlock_irq(&p->pi_lock); put_task_struct(p); @@ -2107,7 +2446,7 @@ __do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask, u32 * Because __kthread_bind() calls this on blocked tasks without * holding rq->lock. */ - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); dequeue_task(rq, p, DEQUEUE_SAVE | DEQUEUE_NOCLOCK); } if (running) @@ -2249,7 +2588,7 @@ static int affine_move_task(struct rq *rq, struct task_struct *p, struct rq_flag init_completion(&my_pending.done); my_pending.arg = (struct migration_arg) { .task = p, - .dest_cpu = -1, /* any */ + .dest_cpu = dest_cpu, .pending = &my_pending, }; @@ -2257,6 +2596,15 @@ static int affine_move_task(struct rq *rq, struct task_struct *p, struct rq_flag } else { pending = p->migration_pending; refcount_inc(&pending->refs); + /* + * Affinity has changed, but we've already installed a + * pending. migration_cpu_stop() *must* see this, else + * we risk a completion of the pending despite having a + * task on a disallowed CPU. + * + * Serialized by p->pi_lock, so this is safe. + */ + pending->arg.dest_cpu = dest_cpu; } } pending = p->migration_pending; @@ -2277,7 +2625,7 @@ static int affine_move_task(struct rq *rq, struct task_struct *p, struct rq_flag return -EINVAL; } - if (task_running(rq, p) || p->state == TASK_WAKING) { + if (task_running(rq, p) || READ_ONCE(p->__state) == TASK_WAKING) { /* * MIGRATE_ENABLE gets here because 'p == current', but for * anything else we cannot do is_migration_disabled(), punt @@ -2420,19 +2768,20 @@ EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); void set_task_cpu(struct task_struct *p, unsigned int new_cpu) { #ifdef CONFIG_SCHED_DEBUG + unsigned int state = READ_ONCE(p->__state); + /* * We should never call set_task_cpu() on a blocked task, * ttwu() will sort out the placement. */ - WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && - !p->on_rq); + WARN_ON_ONCE(state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq); /* * Migrating fair class task must have p->on_rq = TASK_ON_RQ_MIGRATING, * because schedstat_wait_{start,end} rebase migrating task's wait_start * time relying on p->on_rq. */ - WARN_ON_ONCE(p->state == TASK_RUNNING && + WARN_ON_ONCE(state == TASK_RUNNING && p->sched_class == &fair_sched_class && (p->on_rq && !task_on_rq_migrating(p))); @@ -2448,7 +2797,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) * task_rq_lock(). */ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || - lockdep_is_held(&task_rq(p)->lock))); + lockdep_is_held(__rq_lockp(task_rq(p))))); #endif /* * Clearly, migrating tasks to offline CPUs is a fairly daft thing. @@ -2604,7 +2953,7 @@ out: * smp_call_function() if an IPI is sent by the same process we are * waiting to become inactive. */ -unsigned long wait_task_inactive(struct task_struct *p, long match_state) +unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) { int running, queued; struct rq_flags rf; @@ -2632,7 +2981,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state) * is actually now running somewhere else! */ while (task_running(rq, p)) { - if (match_state && unlikely(p->state != match_state)) + if (match_state && unlikely(READ_ONCE(p->__state) != match_state)) return 0; cpu_relax(); } @@ -2647,7 +2996,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state) running = task_running(rq, p); queued = task_on_rq_queued(p); ncsw = 0; - if (!match_state || p->state == match_state) + if (!match_state || READ_ONCE(p->__state) == match_state) ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ task_rq_unlock(rq, p, &rf); @@ -2956,7 +3305,7 @@ static void ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags, struct rq_flags *rf) { check_preempt_curr(rq, p, wake_flags); - p->state = TASK_RUNNING; + WRITE_ONCE(p->__state, TASK_RUNNING); trace_sched_wakeup(p); #ifdef CONFIG_SMP @@ -2979,6 +3328,9 @@ static void ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags, if (rq->avg_idle > max) rq->avg_idle = max; + rq->wake_stamp = jiffies; + rq->wake_avg_idle = rq->avg_idle / 2; + rq->idle_stamp = 0; } #endif @@ -2990,7 +3342,7 @@ ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags, { int en_flags = ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); if (p->sched_contributes_to_load) rq->nr_uninterruptible--; @@ -3345,12 +3697,12 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) * - we're serialized against set_special_state() by virtue of * it disabling IRQs (this allows not taking ->pi_lock). */ - if (!(p->state & state)) + if (!(READ_ONCE(p->__state) & state)) goto out; success = 1; trace_sched_waking(p); - p->state = TASK_RUNNING; + WRITE_ONCE(p->__state, TASK_RUNNING); trace_sched_wakeup(p); goto out; } @@ -3363,7 +3715,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) */ raw_spin_lock_irqsave(&p->pi_lock, flags); smp_mb__after_spinlock(); - if (!(p->state & state)) + if (!(READ_ONCE(p->__state) & state)) goto unlock; trace_sched_waking(p); @@ -3429,7 +3781,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) * TASK_WAKING such that we can unlock p->pi_lock before doing the * enqueue, such as ttwu_queue_wakelist(). */ - p->state = TASK_WAKING; + WRITE_ONCE(p->__state, TASK_WAKING); /* * If the owning (remote) CPU is still in the middle of schedule() with @@ -3522,7 +3874,7 @@ bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct t ret = func(p, arg); rq_unlock(rq, &rf); } else { - switch (p->state) { + switch (READ_ONCE(p->__state)) { case TASK_RUNNING: case TASK_WAKING: break; @@ -3648,7 +4000,6 @@ int sysctl_numa_balancing(struct ctl_table *table, int write, #ifdef CONFIG_SCHEDSTATS DEFINE_STATIC_KEY_FALSE(sched_schedstats); -static bool __initdata __sched_schedstats = false; static void set_schedstats(bool enabled) { @@ -3672,16 +4023,11 @@ static int __init setup_schedstats(char *str) if (!str) goto out; - /* - * This code is called before jump labels have been set up, so we can't - * change the static branch directly just yet. Instead set a temporary - * variable so init_schedstats() can do it later. - */ if (!strcmp(str, "enable")) { - __sched_schedstats = true; + set_schedstats(true); ret = 1; } else if (!strcmp(str, "disable")) { - __sched_schedstats = false; + set_schedstats(false); ret = 1; } out: @@ -3692,11 +4038,6 @@ out: } __setup("schedstats=", setup_schedstats); -static void __init init_schedstats(void) -{ - set_schedstats(__sched_schedstats); -} - #ifdef CONFIG_PROC_SYSCTL int sysctl_schedstats(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) @@ -3718,8 +4059,6 @@ int sysctl_schedstats(struct ctl_table *table, int write, void *buffer, return err; } #endif /* CONFIG_PROC_SYSCTL */ -#else /* !CONFIG_SCHEDSTATS */ -static inline void init_schedstats(void) {} #endif /* CONFIG_SCHEDSTATS */ /* @@ -3735,7 +4074,7 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) * nobody will actually run it, and a signal or other external * event cannot wake it up and insert it on the runqueue either. */ - p->state = TASK_NEW; + p->__state = TASK_NEW; /* * Make sure we do not leak PI boosting priority to the child. @@ -3841,7 +4180,7 @@ void wake_up_new_task(struct task_struct *p) struct rq *rq; raw_spin_lock_irqsave(&p->pi_lock, rf.flags); - p->state = TASK_RUNNING; + WRITE_ONCE(p->__state, TASK_RUNNING); #ifdef CONFIG_SMP /* * Fork balancing, do it here and not earlier because: @@ -4001,7 +4340,7 @@ static void do_balance_callbacks(struct rq *rq, struct callback_head *head) void (*func)(struct rq *rq); struct callback_head *next; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); while (head) { func = (void (*)(struct rq *))head->func; @@ -4024,7 +4363,7 @@ static inline struct callback_head *splice_balance_callbacks(struct rq *rq) { struct callback_head *head = rq->balance_callback; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); if (head) rq->balance_callback = NULL; @@ -4041,9 +4380,9 @@ static inline void balance_callbacks(struct rq *rq, struct callback_head *head) unsigned long flags; if (unlikely(head)) { - raw_spin_lock_irqsave(&rq->lock, flags); + raw_spin_rq_lock_irqsave(rq, flags); do_balance_callbacks(rq, head); - raw_spin_unlock_irqrestore(&rq->lock, flags); + raw_spin_rq_unlock_irqrestore(rq, flags); } } @@ -4074,10 +4413,10 @@ prepare_lock_switch(struct rq *rq, struct task_struct *next, struct rq_flags *rf * do an early lockdep release here: */ rq_unpin_lock(rq, rf); - spin_release(&rq->lock.dep_map, _THIS_IP_); + spin_release(&__rq_lockp(rq)->dep_map, _THIS_IP_); #ifdef CONFIG_DEBUG_SPINLOCK /* this is a valid case when another task releases the spinlock */ - rq->lock.owner = next; + rq_lockp(rq)->owner = next; #endif } @@ -4088,9 +4427,9 @@ static inline void finish_lock_switch(struct rq *rq) * fix up the runqueue lock - which gets 'carried over' from * prev into current: */ - spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); + spin_acquire(&__rq_lockp(rq)->dep_map, 0, 0, _THIS_IP_); __balance_callbacks(rq); - raw_spin_unlock_irq(&rq->lock); + raw_spin_rq_unlock_irq(rq); } /* @@ -4203,7 +4542,7 @@ static struct rq *finish_task_switch(struct task_struct *prev) * running on another CPU and we could rave with its RUNNING -> DEAD * transition, resulting in a double drop. */ - prev_state = prev->state; + prev_state = READ_ONCE(prev->__state); vtime_task_switch(prev); perf_event_task_sched_in(prev, current); finish_task(prev); @@ -4348,9 +4687,9 @@ context_switch(struct rq *rq, struct task_struct *prev, * externally visible scheduler statistics: current number of runnable * threads, total number of context switches performed since bootup. */ -unsigned long nr_running(void) +unsigned int nr_running(void) { - unsigned long i, sum = 0; + unsigned int i, sum = 0; for_each_online_cpu(i) sum += cpu_rq(i)->nr_running; @@ -4395,7 +4734,7 @@ unsigned long long nr_context_switches(void) * it does become runnable. */ -unsigned long nr_iowait_cpu(int cpu) +unsigned int nr_iowait_cpu(int cpu) { return atomic_read(&cpu_rq(cpu)->nr_iowait); } @@ -4430,9 +4769,9 @@ unsigned long nr_iowait_cpu(int cpu) * Task CPU affinities can make all that even more 'interesting'. */ -unsigned long nr_iowait(void) +unsigned int nr_iowait(void) { - unsigned long i, sum = 0; + unsigned int i, sum = 0; for_each_possible_cpu(i) sum += nr_iowait_cpu(i); @@ -4897,7 +5236,7 @@ static inline void schedule_debug(struct task_struct *prev, bool preempt) #endif #ifdef CONFIG_DEBUG_ATOMIC_SLEEP - if (!preempt && prev->state && prev->non_block_count) { + if (!preempt && READ_ONCE(prev->__state) && prev->non_block_count) { printk(KERN_ERR "BUG: scheduling in a non-blocking section: %s/%d/%i\n", prev->comm, prev->pid, prev->non_block_count); dump_stack(); @@ -4943,7 +5282,7 @@ static void put_prev_task_balance(struct rq *rq, struct task_struct *prev, * Pick up the highest-prio task: */ static inline struct task_struct * -pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +__pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { const struct sched_class *class; struct task_struct *p; @@ -4961,7 +5300,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) if (unlikely(p == RETRY_TASK)) goto restart; - /* Assumes fair_sched_class->next == idle_sched_class */ + /* Assume the next prioritized class is idle_sched_class */ if (!p) { put_prev_task(rq, prev); p = pick_next_task_idle(rq); @@ -4983,6 +5322,455 @@ restart: BUG(); } +#ifdef CONFIG_SCHED_CORE +static inline bool is_task_rq_idle(struct task_struct *t) +{ + return (task_rq(t)->idle == t); +} + +static inline bool cookie_equals(struct task_struct *a, unsigned long cookie) +{ + return is_task_rq_idle(a) || (a->core_cookie == cookie); +} + +static inline bool cookie_match(struct task_struct *a, struct task_struct *b) +{ + if (is_task_rq_idle(a) || is_task_rq_idle(b)) + return true; + + return a->core_cookie == b->core_cookie; +} + +// XXX fairness/fwd progress conditions +/* + * Returns + * - NULL if there is no runnable task for this class. + * - the highest priority task for this runqueue if it matches + * rq->core->core_cookie or its priority is greater than max. + * - Else returns idle_task. + */ +static struct task_struct * +pick_task(struct rq *rq, const struct sched_class *class, struct task_struct *max, bool in_fi) +{ + struct task_struct *class_pick, *cookie_pick; + unsigned long cookie = rq->core->core_cookie; + + class_pick = class->pick_task(rq); + if (!class_pick) + return NULL; + + if (!cookie) { + /* + * If class_pick is tagged, return it only if it has + * higher priority than max. + */ + if (max && class_pick->core_cookie && + prio_less(class_pick, max, in_fi)) + return idle_sched_class.pick_task(rq); + + return class_pick; + } + + /* + * If class_pick is idle or matches cookie, return early. + */ + if (cookie_equals(class_pick, cookie)) + return class_pick; + + cookie_pick = sched_core_find(rq, cookie); + + /* + * If class > max && class > cookie, it is the highest priority task on + * the core (so far) and it must be selected, otherwise we must go with + * the cookie pick in order to satisfy the constraint. + */ + if (prio_less(cookie_pick, class_pick, in_fi) && + (!max || prio_less(max, class_pick, in_fi))) + return class_pick; + + return cookie_pick; +} + +extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); + +static struct task_struct * +pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +{ + struct task_struct *next, *max = NULL; + const struct sched_class *class; + const struct cpumask *smt_mask; + bool fi_before = false; + int i, j, cpu, occ = 0; + bool need_sync; + + if (!sched_core_enabled(rq)) + return __pick_next_task(rq, prev, rf); + + cpu = cpu_of(rq); + + /* Stopper task is switching into idle, no need core-wide selection. */ + if (cpu_is_offline(cpu)) { + /* + * Reset core_pick so that we don't enter the fastpath when + * coming online. core_pick would already be migrated to + * another cpu during offline. + */ + rq->core_pick = NULL; + return __pick_next_task(rq, prev, rf); + } + + /* + * If there were no {en,de}queues since we picked (IOW, the task + * pointers are all still valid), and we haven't scheduled the last + * pick yet, do so now. + * + * rq->core_pick can be NULL if no selection was made for a CPU because + * it was either offline or went offline during a sibling's core-wide + * selection. In this case, do a core-wide selection. + */ + if (rq->core->core_pick_seq == rq->core->core_task_seq && + rq->core->core_pick_seq != rq->core_sched_seq && + rq->core_pick) { + WRITE_ONCE(rq->core_sched_seq, rq->core->core_pick_seq); + + next = rq->core_pick; + if (next != prev) { + put_prev_task(rq, prev); + set_next_task(rq, next); + } + + rq->core_pick = NULL; + return next; + } + + put_prev_task_balance(rq, prev, rf); + + smt_mask = cpu_smt_mask(cpu); + need_sync = !!rq->core->core_cookie; + + /* reset state */ + rq->core->core_cookie = 0UL; + if (rq->core->core_forceidle) { + need_sync = true; + fi_before = true; + rq->core->core_forceidle = false; + } + + /* + * core->core_task_seq, core->core_pick_seq, rq->core_sched_seq + * + * @task_seq guards the task state ({en,de}queues) + * @pick_seq is the @task_seq we did a selection on + * @sched_seq is the @pick_seq we scheduled + * + * However, preemptions can cause multiple picks on the same task set. + * 'Fix' this by also increasing @task_seq for every pick. + */ + rq->core->core_task_seq++; + + /* + * Optimize for common case where this CPU has no cookies + * and there are no cookied tasks running on siblings. + */ + if (!need_sync) { + for_each_class(class) { + next = class->pick_task(rq); + if (next) + break; + } + + if (!next->core_cookie) { + rq->core_pick = NULL; + /* + * For robustness, update the min_vruntime_fi for + * unconstrained picks as well. + */ + WARN_ON_ONCE(fi_before); + task_vruntime_update(rq, next, false); + goto done; + } + } + + for_each_cpu(i, smt_mask) { + struct rq *rq_i = cpu_rq(i); + + rq_i->core_pick = NULL; + + if (i != cpu) + update_rq_clock(rq_i); + } + + /* + * Try and select tasks for each sibling in descending sched_class + * order. + */ + for_each_class(class) { +again: + for_each_cpu_wrap(i, smt_mask, cpu) { + struct rq *rq_i = cpu_rq(i); + struct task_struct *p; + + if (rq_i->core_pick) + continue; + + /* + * If this sibling doesn't yet have a suitable task to + * run; ask for the most eligible task, given the + * highest priority task already selected for this + * core. + */ + p = pick_task(rq_i, class, max, fi_before); + if (!p) + continue; + + if (!is_task_rq_idle(p)) + occ++; + + rq_i->core_pick = p; + if (rq_i->idle == p && rq_i->nr_running) { + rq->core->core_forceidle = true; + if (!fi_before) + rq->core->core_forceidle_seq++; + } + + /* + * If this new candidate is of higher priority than the + * previous; and they're incompatible; we need to wipe + * the slate and start over. pick_task makes sure that + * p's priority is more than max if it doesn't match + * max's cookie. + * + * NOTE: this is a linear max-filter and is thus bounded + * in execution time. + */ + if (!max || !cookie_match(max, p)) { + struct task_struct *old_max = max; + + rq->core->core_cookie = p->core_cookie; + max = p; + + if (old_max) { + rq->core->core_forceidle = false; + for_each_cpu(j, smt_mask) { + if (j == i) + continue; + + cpu_rq(j)->core_pick = NULL; + } + occ = 1; + goto again; + } + } + } + } + + rq->core->core_pick_seq = rq->core->core_task_seq; + next = rq->core_pick; + rq->core_sched_seq = rq->core->core_pick_seq; + + /* Something should have been selected for current CPU */ + WARN_ON_ONCE(!next); + + /* + * Reschedule siblings + * + * NOTE: L1TF -- at this point we're no longer running the old task and + * sending an IPI (below) ensures the sibling will no longer be running + * their task. This ensures there is no inter-sibling overlap between + * non-matching user state. + */ + for_each_cpu(i, smt_mask) { + struct rq *rq_i = cpu_rq(i); + + /* + * An online sibling might have gone offline before a task + * could be picked for it, or it might be offline but later + * happen to come online, but its too late and nothing was + * picked for it. That's Ok - it will pick tasks for itself, + * so ignore it. + */ + if (!rq_i->core_pick) + continue; + + /* + * Update for new !FI->FI transitions, or if continuing to be in !FI: + * fi_before fi update? + * 0 0 1 + * 0 1 1 + * 1 0 1 + * 1 1 0 + */ + if (!(fi_before && rq->core->core_forceidle)) + task_vruntime_update(rq_i, rq_i->core_pick, rq->core->core_forceidle); + + rq_i->core_pick->core_occupation = occ; + + if (i == cpu) { + rq_i->core_pick = NULL; + continue; + } + + /* Did we break L1TF mitigation requirements? */ + WARN_ON_ONCE(!cookie_match(next, rq_i->core_pick)); + + if (rq_i->curr == rq_i->core_pick) { + rq_i->core_pick = NULL; + continue; + } + + resched_curr(rq_i); + } + +done: + set_next_task(rq, next); + return next; +} + +static bool try_steal_cookie(int this, int that) +{ + struct rq *dst = cpu_rq(this), *src = cpu_rq(that); + struct task_struct *p; + unsigned long cookie; + bool success = false; + + local_irq_disable(); + double_rq_lock(dst, src); + + cookie = dst->core->core_cookie; + if (!cookie) + goto unlock; + + if (dst->curr != dst->idle) + goto unlock; + + p = sched_core_find(src, cookie); + if (p == src->idle) + goto unlock; + + do { + if (p == src->core_pick || p == src->curr) + goto next; + + if (!cpumask_test_cpu(this, &p->cpus_mask)) + goto next; + + if (p->core_occupation > dst->idle->core_occupation) + goto next; + + p->on_rq = TASK_ON_RQ_MIGRATING; + deactivate_task(src, p, 0); + set_task_cpu(p, this); + activate_task(dst, p, 0); + p->on_rq = TASK_ON_RQ_QUEUED; + + resched_curr(dst); + + success = true; + break; + +next: + p = sched_core_next(p, cookie); + } while (p); + +unlock: + double_rq_unlock(dst, src); + local_irq_enable(); + + return success; +} + +static bool steal_cookie_task(int cpu, struct sched_domain *sd) +{ + int i; + + for_each_cpu_wrap(i, sched_domain_span(sd), cpu) { + if (i == cpu) + continue; + + if (need_resched()) + break; + + if (try_steal_cookie(cpu, i)) + return true; + } + + return false; +} + +static void sched_core_balance(struct rq *rq) +{ + struct sched_domain *sd; + int cpu = cpu_of(rq); + + preempt_disable(); + rcu_read_lock(); + raw_spin_rq_unlock_irq(rq); + for_each_domain(cpu, sd) { + if (need_resched()) + break; + + if (steal_cookie_task(cpu, sd)) + break; + } + raw_spin_rq_lock_irq(rq); + rcu_read_unlock(); + preempt_enable(); +} + +static DEFINE_PER_CPU(struct callback_head, core_balance_head); + +void queue_core_balance(struct rq *rq) +{ + if (!sched_core_enabled(rq)) + return; + + if (!rq->core->core_cookie) + return; + + if (!rq->nr_running) /* not forced idle */ + return; + + queue_balance_callback(rq, &per_cpu(core_balance_head, rq->cpu), sched_core_balance); +} + +static inline void sched_core_cpu_starting(unsigned int cpu) +{ + const struct cpumask *smt_mask = cpu_smt_mask(cpu); + struct rq *rq, *core_rq = NULL; + int i; + + core_rq = cpu_rq(cpu)->core; + + if (!core_rq) { + for_each_cpu(i, smt_mask) { + rq = cpu_rq(i); + if (rq->core && rq->core == rq) + core_rq = rq; + } + + if (!core_rq) + core_rq = cpu_rq(cpu); + + for_each_cpu(i, smt_mask) { + rq = cpu_rq(i); + + WARN_ON_ONCE(rq->core && rq->core != core_rq); + rq->core = core_rq; + } + } +} +#else /* !CONFIG_SCHED_CORE */ + +static inline void sched_core_cpu_starting(unsigned int cpu) {} + +static struct task_struct * +pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +{ + return __pick_next_task(rq, prev, rf); +} + +#endif /* CONFIG_SCHED_CORE */ + /* * __schedule() is the main scheduler function. * @@ -5074,10 +5862,10 @@ static void __sched notrace __schedule(bool preempt) * - we form a control dependency vs deactivate_task() below. * - ptrace_{,un}freeze_traced() can change ->state underneath us. */ - prev_state = prev->state; + prev_state = READ_ONCE(prev->__state); if (!preempt && prev_state) { if (signal_pending_state(prev_state, prev)) { - prev->state = TASK_RUNNING; + WRITE_ONCE(prev->__state, TASK_RUNNING); } else { prev->sched_contributes_to_load = (prev_state & TASK_UNINTERRUPTIBLE) && @@ -5150,7 +5938,7 @@ static void __sched notrace __schedule(bool preempt) rq_unpin_lock(rq, &rf); __balance_callbacks(rq); - raw_spin_unlock_irq(&rq->lock); + raw_spin_rq_unlock_irq(rq); } } @@ -5174,7 +5962,7 @@ static inline void sched_submit_work(struct task_struct *tsk) { unsigned int task_flags; - if (!tsk->state) + if (task_is_running(tsk)) return; task_flags = tsk->flags; @@ -5249,7 +6037,7 @@ void __sched schedule_idle(void) * current task can be in any other state. Note, idle is always in the * TASK_RUNNING state. */ - WARN_ON_ONCE(current->state); + WARN_ON_ONCE(current->__state); do { __schedule(false); } while (need_resched()); @@ -5692,7 +6480,7 @@ out_unlock: rq_unpin_lock(rq, &rf); __balance_callbacks(rq); - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); preempt_enable(); } @@ -7148,7 +7936,7 @@ again: if (curr->sched_class != p->sched_class) goto out_unlock; - if (task_running(p_rq, p) || p->state) + if (task_running(p_rq, p) || !task_is_running(p)) goto out_unlock; yielded = curr->sched_class->yield_to_task(rq, p); @@ -7351,7 +8139,7 @@ void sched_show_task(struct task_struct *p) pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p)); - if (p->state == TASK_RUNNING) + if (task_is_running(p)) pr_cont(" running task "); #ifdef CONFIG_DEBUG_STACK_USAGE free = stack_not_used(p); @@ -7375,26 +8163,28 @@ EXPORT_SYMBOL_GPL(sched_show_task); static inline bool state_filter_match(unsigned long state_filter, struct task_struct *p) { + unsigned int state = READ_ONCE(p->__state); + /* no filter, everything matches */ if (!state_filter) return true; /* filter, but doesn't match */ - if (!(p->state & state_filter)) + if (!(state & state_filter)) return false; /* * When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows * TASK_KILLABLE). */ - if (state_filter == TASK_UNINTERRUPTIBLE && p->state == TASK_IDLE) + if (state_filter == TASK_UNINTERRUPTIBLE && state == TASK_IDLE) return false; return true; } -void show_state_filter(unsigned long state_filter) +void show_state_filter(unsigned int state_filter) { struct task_struct *g, *p; @@ -7433,19 +8223,32 @@ void show_state_filter(unsigned long state_filter) * NOTE: this function does not set the idle thread's NEED_RESCHED * flag, to make booting more robust. */ -void init_idle(struct task_struct *idle, int cpu) +void __init init_idle(struct task_struct *idle, int cpu) { struct rq *rq = cpu_rq(cpu); unsigned long flags; __sched_fork(0, idle); + /* + * The idle task doesn't need the kthread struct to function, but it + * is dressed up as a per-CPU kthread and thus needs to play the part + * if we want to avoid special-casing it in code that deals with per-CPU + * kthreads. + */ + set_kthread_struct(idle); + raw_spin_lock_irqsave(&idle->pi_lock, flags); - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); - idle->state = TASK_RUNNING; + idle->__state = TASK_RUNNING; idle->se.exec_start = sched_clock(); - idle->flags |= PF_IDLE; + /* + * PF_KTHREAD should already be set at this point; regardless, make it + * look like a proper per-CPU kthread. + */ + idle->flags |= PF_IDLE | PF_KTHREAD | PF_NO_SETAFFINITY; + kthread_set_per_cpu(idle, cpu); scs_task_reset(idle); kasan_unpoison_task_stack(idle); @@ -7479,7 +8282,7 @@ void init_idle(struct task_struct *idle, int cpu) #ifdef CONFIG_SMP idle->on_cpu = 1; #endif - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); raw_spin_unlock_irqrestore(&idle->pi_lock, flags); /* Set the preempt count _outside_ the spinlocks! */ @@ -7645,7 +8448,7 @@ static void balance_push(struct rq *rq) { struct task_struct *push_task = rq->curr; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); SCHED_WARN_ON(rq->cpu != smp_processor_id()); /* @@ -7662,12 +8465,8 @@ static void balance_push(struct rq *rq) /* * Both the cpu-hotplug and stop task are in this case and are * required to complete the hotplug process. - * - * XXX: the idle task does not match kthread_is_per_cpu() due to - * histerical raisins. */ - if (rq->idle == push_task || - kthread_is_per_cpu(push_task) || + if (kthread_is_per_cpu(push_task) || is_migration_disabled(push_task)) { /* @@ -7683,9 +8482,9 @@ static void balance_push(struct rq *rq) */ if (!rq->nr_running && !rq_has_pinned_tasks(rq) && rcuwait_active(&rq->hotplug_wait)) { - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); rcuwait_wake_up(&rq->hotplug_wait); - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); } return; } @@ -7695,7 +8494,7 @@ static void balance_push(struct rq *rq) * Temporarily drop rq->lock such that we can wake-up the stop task. * Both preemption and IRQs are still disabled. */ - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); stop_one_cpu_nowait(rq->cpu, __balance_push_cpu_stop, push_task, this_cpu_ptr(&push_work)); /* @@ -7703,7 +8502,7 @@ static void balance_push(struct rq *rq) * schedule(). The next pick is obviously going to be the stop task * which kthread_is_per_cpu() and will push this task away. */ - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); } static void balance_push_set(int cpu, bool on) @@ -7947,6 +8746,7 @@ static void sched_rq_cpu_starting(unsigned int cpu) int sched_cpu_starting(unsigned int cpu) { + sched_core_cpu_starting(cpu); sched_rq_cpu_starting(cpu); sched_tick_start(cpu); return 0; @@ -7993,7 +8793,7 @@ static void dump_rq_tasks(struct rq *rq, const char *loglvl) struct task_struct *g, *p; int cpu = cpu_of(rq); - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); printk("%sCPU%d enqueued tasks (%u total):\n", loglvl, cpu, rq->nr_running); for_each_process_thread(g, p) { @@ -8045,6 +8845,7 @@ void __init sched_init_smp(void) /* Move init over to a non-isolated CPU */ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0) BUG(); + current->flags &= ~PF_NO_SETAFFINITY; sched_init_granularity(); init_sched_rt_class(); @@ -8166,7 +8967,7 @@ void __init sched_init(void) struct rq *rq; rq = cpu_rq(i); - raw_spin_lock_init(&rq->lock); + raw_spin_lock_init(&rq->__lock); rq->nr_running = 0; rq->calc_load_active = 0; rq->calc_load_update = jiffies + LOAD_FREQ; @@ -8214,6 +9015,8 @@ void __init sched_init(void) rq->online = 0; rq->idle_stamp = 0; rq->avg_idle = 2*sysctl_sched_migration_cost; + rq->wake_stamp = jiffies; + rq->wake_avg_idle = rq->avg_idle; rq->max_idle_balance_cost = sysctl_sched_migration_cost; INIT_LIST_HEAD(&rq->cfs_tasks); @@ -8231,6 +9034,16 @@ void __init sched_init(void) #endif /* CONFIG_SMP */ hrtick_rq_init(rq); atomic_set(&rq->nr_iowait, 0); + +#ifdef CONFIG_SCHED_CORE + rq->core = NULL; + rq->core_pick = NULL; + rq->core_enabled = 0; + rq->core_tree = RB_ROOT; + rq->core_forceidle = false; + + rq->core_cookie = 0UL; +#endif } set_load_weight(&init_task, false); @@ -8257,8 +9070,6 @@ void __init sched_init(void) #endif init_sched_fair_class(); - init_schedstats(); - psi_init(); init_uclamp(); @@ -8276,15 +9087,15 @@ static inline int preempt_count_equals(int preempt_offset) void __might_sleep(const char *file, int line, int preempt_offset) { + unsigned int state = get_current_state(); /* * Blocking primitives will set (and therefore destroy) current->state, * since we will exit with TASK_RUNNING make sure we enter with it, * otherwise we will destroy state. */ - WARN_ONCE(current->state != TASK_RUNNING && current->task_state_change, + WARN_ONCE(state != TASK_RUNNING && current->task_state_change, "do not call blocking ops when !TASK_RUNNING; " - "state=%lx set at [<%p>] %pS\n", - current->state, + "state=%x set at [<%p>] %pS\n", state, (void *)current->task_state_change, (void *)current->task_state_change); @@ -8680,7 +9491,11 @@ static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) #ifdef CONFIG_UCLAMP_TASK_GROUP /* Propagate the effective uclamp value for the new group */ + mutex_lock(&uclamp_mutex); + rcu_read_lock(); cpu_util_update_eff(css); + rcu_read_unlock(); + mutex_unlock(&uclamp_mutex); #endif return 0; @@ -8741,7 +9556,7 @@ static int cpu_cgroup_can_attach(struct cgroup_taskset *tset) * has happened. This would lead to problems with PELT, due to * move wanting to detach+attach while we're not attached yet. */ - if (task->state == TASK_NEW) + if (READ_ONCE(task->__state) == TASK_NEW) ret = -EINVAL; raw_spin_unlock_irq(&task->pi_lock); @@ -8770,6 +9585,9 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css) enum uclamp_id clamp_id; unsigned int clamps; + lockdep_assert_held(&uclamp_mutex); + SCHED_WARN_ON(!rcu_read_lock_held()); + css_for_each_descendant_pre(css, top_css) { uc_parent = css_tg(css)->parent ? css_tg(css)->parent->uclamp : NULL; @@ -8802,7 +9620,7 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css) } /* Immediately update descendants RUNNABLE tasks */ - uclamp_update_active_tasks(css, clamps); + uclamp_update_active_tasks(css); } } @@ -8961,7 +9779,8 @@ static const u64 max_cfs_runtime = MAX_BW * NSEC_PER_USEC; static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); -static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) +static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota, + u64 burst) { int i, ret = 0, runtime_enabled, runtime_was_enabled; struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; @@ -8991,6 +9810,10 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) if (quota != RUNTIME_INF && quota > max_cfs_runtime) return -EINVAL; + if (quota != RUNTIME_INF && (burst > quota || + burst + quota > max_cfs_runtime)) + return -EINVAL; + /* * Prevent race between setting of cfs_rq->runtime_enabled and * unthrottle_offline_cfs_rqs(). @@ -9012,6 +9835,7 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) raw_spin_lock_irq(&cfs_b->lock); cfs_b->period = ns_to_ktime(period); cfs_b->quota = quota; + cfs_b->burst = burst; __refill_cfs_bandwidth_runtime(cfs_b); @@ -9045,9 +9869,10 @@ out_unlock: static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) { - u64 quota, period; + u64 quota, period, burst; period = ktime_to_ns(tg->cfs_bandwidth.period); + burst = tg->cfs_bandwidth.burst; if (cfs_quota_us < 0) quota = RUNTIME_INF; else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC) @@ -9055,7 +9880,7 @@ static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) else return -EINVAL; - return tg_set_cfs_bandwidth(tg, period, quota); + return tg_set_cfs_bandwidth(tg, period, quota, burst); } static long tg_get_cfs_quota(struct task_group *tg) @@ -9073,15 +9898,16 @@ static long tg_get_cfs_quota(struct task_group *tg) static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) { - u64 quota, period; + u64 quota, period, burst; if ((u64)cfs_period_us > U64_MAX / NSEC_PER_USEC) return -EINVAL; period = (u64)cfs_period_us * NSEC_PER_USEC; quota = tg->cfs_bandwidth.quota; + burst = tg->cfs_bandwidth.burst; - return tg_set_cfs_bandwidth(tg, period, quota); + return tg_set_cfs_bandwidth(tg, period, quota, burst); } static long tg_get_cfs_period(struct task_group *tg) @@ -9094,6 +9920,30 @@ static long tg_get_cfs_period(struct task_group *tg) return cfs_period_us; } +static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us) +{ + u64 quota, period, burst; + + if ((u64)cfs_burst_us > U64_MAX / NSEC_PER_USEC) + return -EINVAL; + + burst = (u64)cfs_burst_us * NSEC_PER_USEC; + period = ktime_to_ns(tg->cfs_bandwidth.period); + quota = tg->cfs_bandwidth.quota; + + return tg_set_cfs_bandwidth(tg, period, quota, burst); +} + +static long tg_get_cfs_burst(struct task_group *tg) +{ + u64 burst_us; + + burst_us = tg->cfs_bandwidth.burst; + do_div(burst_us, NSEC_PER_USEC); + + return burst_us; +} + static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css, struct cftype *cft) { @@ -9118,6 +9968,18 @@ static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css, return tg_set_cfs_period(css_tg(css), cfs_period_us); } +static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css, + struct cftype *cft) +{ + return tg_get_cfs_burst(css_tg(css)); +} + +static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css, + struct cftype *cftype, u64 cfs_burst_us) +{ + return tg_set_cfs_burst(css_tg(css), cfs_burst_us); +} + struct cfs_schedulable_data { struct task_group *tg; u64 period, quota; @@ -9271,6 +10133,11 @@ static struct cftype cpu_legacy_files[] = { .write_u64 = cpu_cfs_period_write_u64, }, { + .name = "cfs_burst_us", + .read_u64 = cpu_cfs_burst_read_u64, + .write_u64 = cpu_cfs_burst_write_u64, + }, + { .name = "stat", .seq_show = cpu_cfs_stat_show, }, @@ -9435,12 +10302,13 @@ static ssize_t cpu_max_write(struct kernfs_open_file *of, { struct task_group *tg = css_tg(of_css(of)); u64 period = tg_get_cfs_period(tg); + u64 burst = tg_get_cfs_burst(tg); u64 quota; int ret; ret = cpu_period_quota_parse(buf, &period, "a); if (!ret) - ret = tg_set_cfs_bandwidth(tg, period, quota); + ret = tg_set_cfs_bandwidth(tg, period, quota, burst); return ret ?: nbytes; } #endif @@ -9467,6 +10335,12 @@ static struct cftype cpu_files[] = { .seq_show = cpu_max_show, .write = cpu_max_write, }, + { + .name = "max.burst", + .flags = CFTYPE_NOT_ON_ROOT, + .read_u64 = cpu_cfs_burst_read_u64, + .write_u64 = cpu_cfs_burst_write_u64, + }, #endif #ifdef CONFIG_UCLAMP_TASK_GROUP { diff --git a/kernel/sched/core_sched.c b/kernel/sched/core_sched.c new file mode 100644 index 000000000000..9a80e9a474c0 --- /dev/null +++ b/kernel/sched/core_sched.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/prctl.h> +#include "sched.h" + +/* + * A simple wrapper around refcount. An allocated sched_core_cookie's + * address is used to compute the cookie of the task. + */ +struct sched_core_cookie { + refcount_t refcnt; +}; + +unsigned long sched_core_alloc_cookie(void) +{ + struct sched_core_cookie *ck = kmalloc(sizeof(*ck), GFP_KERNEL); + if (!ck) + return 0; + + refcount_set(&ck->refcnt, 1); + sched_core_get(); + + return (unsigned long)ck; +} + +void sched_core_put_cookie(unsigned long cookie) +{ + struct sched_core_cookie *ptr = (void *)cookie; + + if (ptr && refcount_dec_and_test(&ptr->refcnt)) { + kfree(ptr); + sched_core_put(); + } +} + +unsigned long sched_core_get_cookie(unsigned long cookie) +{ + struct sched_core_cookie *ptr = (void *)cookie; + + if (ptr) + refcount_inc(&ptr->refcnt); + + return cookie; +} + +/* + * sched_core_update_cookie - replace the cookie on a task + * @p: the task to update + * @cookie: the new cookie + * + * Effectively exchange the task cookie; caller is responsible for lifetimes on + * both ends. + * + * Returns: the old cookie + */ +unsigned long sched_core_update_cookie(struct task_struct *p, unsigned long cookie) +{ + unsigned long old_cookie; + struct rq_flags rf; + struct rq *rq; + bool enqueued; + + rq = task_rq_lock(p, &rf); + + /* + * Since creating a cookie implies sched_core_get(), and we cannot set + * a cookie until after we've created it, similarly, we cannot destroy + * a cookie until after we've removed it, we must have core scheduling + * enabled here. + */ + SCHED_WARN_ON((p->core_cookie || cookie) && !sched_core_enabled(rq)); + + enqueued = sched_core_enqueued(p); + if (enqueued) + sched_core_dequeue(rq, p); + + old_cookie = p->core_cookie; + p->core_cookie = cookie; + + if (enqueued) + sched_core_enqueue(rq, p); + + /* + * If task is currently running, it may not be compatible anymore after + * the cookie change, so enter the scheduler on its CPU to schedule it + * away. + */ + if (task_running(rq, p)) + resched_curr(rq); + + task_rq_unlock(rq, p, &rf); + + return old_cookie; +} + +static unsigned long sched_core_clone_cookie(struct task_struct *p) +{ + unsigned long cookie, flags; + + raw_spin_lock_irqsave(&p->pi_lock, flags); + cookie = sched_core_get_cookie(p->core_cookie); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); + + return cookie; +} + +void sched_core_fork(struct task_struct *p) +{ + RB_CLEAR_NODE(&p->core_node); + p->core_cookie = sched_core_clone_cookie(current); +} + +void sched_core_free(struct task_struct *p) +{ + sched_core_put_cookie(p->core_cookie); +} + +static void __sched_core_set(struct task_struct *p, unsigned long cookie) +{ + cookie = sched_core_get_cookie(cookie); + cookie = sched_core_update_cookie(p, cookie); + sched_core_put_cookie(cookie); +} + +/* Called from prctl interface: PR_SCHED_CORE */ +int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, + unsigned long uaddr) +{ + unsigned long cookie = 0, id = 0; + struct task_struct *task, *p; + struct pid *grp; + int err = 0; + + if (!static_branch_likely(&sched_smt_present)) + return -ENODEV; + + if (type > PIDTYPE_PGID || cmd >= PR_SCHED_CORE_MAX || pid < 0 || + (cmd != PR_SCHED_CORE_GET && uaddr)) + return -EINVAL; + + rcu_read_lock(); + if (pid == 0) { + task = current; + } else { + task = find_task_by_vpid(pid); + if (!task) { + rcu_read_unlock(); + return -ESRCH; + } + } + get_task_struct(task); + rcu_read_unlock(); + + /* + * Check if this process has the right to modify the specified + * process. Use the regular "ptrace_may_access()" checks. + */ + if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) { + err = -EPERM; + goto out; + } + + switch (cmd) { + case PR_SCHED_CORE_GET: + if (type != PIDTYPE_PID || uaddr & 7) { + err = -EINVAL; + goto out; + } + cookie = sched_core_clone_cookie(task); + if (cookie) { + /* XXX improve ? */ + ptr_to_hashval((void *)cookie, &id); + } + err = put_user(id, (u64 __user *)uaddr); + goto out; + + case PR_SCHED_CORE_CREATE: + cookie = sched_core_alloc_cookie(); + if (!cookie) { + err = -ENOMEM; + goto out; + } + break; + + case PR_SCHED_CORE_SHARE_TO: + cookie = sched_core_clone_cookie(current); + break; + + case PR_SCHED_CORE_SHARE_FROM: + if (type != PIDTYPE_PID) { + err = -EINVAL; + goto out; + } + cookie = sched_core_clone_cookie(task); + __sched_core_set(current, cookie); + goto out; + + default: + err = -EINVAL; + goto out; + }; + + if (type == PIDTYPE_PID) { + __sched_core_set(task, cookie); + goto out; + } + + read_lock(&tasklist_lock); + grp = task_pid_type(task, type); + + do_each_pid_thread(grp, type, p) { + if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS)) { + err = -EPERM; + goto out_tasklist; + } + } while_each_pid_thread(grp, type, p); + + do_each_pid_thread(grp, type, p) { + __sched_core_set(p, cookie); + } while_each_pid_thread(grp, type, p); +out_tasklist: + read_unlock(&tasklist_lock); + +out: + sched_core_put_cookie(cookie); + put_task_struct(task); + return err; +} + diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 104a1bade14f..893eece65bfd 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -112,7 +112,7 @@ static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu, /* * Take rq->lock to make 64-bit read safe on 32-bit platforms. */ - raw_spin_lock_irq(&cpu_rq(cpu)->lock); + raw_spin_rq_lock_irq(cpu_rq(cpu)); #endif if (index == CPUACCT_STAT_NSTATS) { @@ -126,7 +126,7 @@ static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu, } #ifndef CONFIG_64BIT - raw_spin_unlock_irq(&cpu_rq(cpu)->lock); + raw_spin_rq_unlock_irq(cpu_rq(cpu)); #endif return data; @@ -141,14 +141,14 @@ static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) /* * Take rq->lock to make 64-bit write safe on 32-bit platforms. */ - raw_spin_lock_irq(&cpu_rq(cpu)->lock); + raw_spin_rq_lock_irq(cpu_rq(cpu)); #endif for (i = 0; i < CPUACCT_STAT_NSTATS; i++) cpuusage->usages[i] = val; #ifndef CONFIG_64BIT - raw_spin_unlock_irq(&cpu_rq(cpu)->lock); + raw_spin_rq_unlock_irq(cpu_rq(cpu)); #endif } @@ -253,13 +253,13 @@ static int cpuacct_all_seq_show(struct seq_file *m, void *V) * Take rq->lock to make 64-bit read safe on 32-bit * platforms. */ - raw_spin_lock_irq(&cpu_rq(cpu)->lock); + raw_spin_rq_lock_irq(cpu_rq(cpu)); #endif seq_printf(m, " %llu", cpuusage->usages[index]); #ifndef CONFIG_64BIT - raw_spin_unlock_irq(&cpu_rq(cpu)->lock); + raw_spin_rq_unlock_irq(cpu_rq(cpu)); #endif } seq_puts(m, "\n"); diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 4f09afd2f321..57124614363d 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -151,6 +151,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, unsigned int freq = arch_scale_freq_invariant() ? policy->cpuinfo.max_freq : policy->cur; + util = map_util_perf(util); freq = map_util_freq(util, freq, max); if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 9a2989749b8d..aaacd6cfd42f 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -157,7 +157,7 @@ void __add_running_bw(u64 dl_bw, struct dl_rq *dl_rq) { u64 old = dl_rq->running_bw; - lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); + lockdep_assert_rq_held(rq_of_dl_rq(dl_rq)); dl_rq->running_bw += dl_bw; SCHED_WARN_ON(dl_rq->running_bw < old); /* overflow */ SCHED_WARN_ON(dl_rq->running_bw > dl_rq->this_bw); @@ -170,7 +170,7 @@ void __sub_running_bw(u64 dl_bw, struct dl_rq *dl_rq) { u64 old = dl_rq->running_bw; - lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); + lockdep_assert_rq_held(rq_of_dl_rq(dl_rq)); dl_rq->running_bw -= dl_bw; SCHED_WARN_ON(dl_rq->running_bw > old); /* underflow */ if (dl_rq->running_bw > old) @@ -184,7 +184,7 @@ void __add_rq_bw(u64 dl_bw, struct dl_rq *dl_rq) { u64 old = dl_rq->this_bw; - lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); + lockdep_assert_rq_held(rq_of_dl_rq(dl_rq)); dl_rq->this_bw += dl_bw; SCHED_WARN_ON(dl_rq->this_bw < old); /* overflow */ } @@ -194,7 +194,7 @@ void __sub_rq_bw(u64 dl_bw, struct dl_rq *dl_rq) { u64 old = dl_rq->this_bw; - lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); + lockdep_assert_rq_held(rq_of_dl_rq(dl_rq)); dl_rq->this_bw -= dl_bw; SCHED_WARN_ON(dl_rq->this_bw > old); /* underflow */ if (dl_rq->this_bw > old) @@ -348,10 +348,10 @@ static void task_non_contending(struct task_struct *p) if ((zerolag_time < 0) || hrtimer_active(&dl_se->inactive_timer)) { if (dl_task(p)) sub_running_bw(dl_se, dl_rq); - if (!dl_task(p) || p->state == TASK_DEAD) { + if (!dl_task(p) || READ_ONCE(p->__state) == TASK_DEAD) { struct dl_bw *dl_b = dl_bw_of(task_cpu(p)); - if (p->state == TASK_DEAD) + if (READ_ONCE(p->__state) == TASK_DEAD) sub_rq_bw(&p->dl, &rq->dl); raw_spin_lock(&dl_b->lock); __dl_sub(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); @@ -987,7 +987,7 @@ static int start_dl_timer(struct task_struct *p) ktime_t now, act; s64 delta; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); /* * We want the timer to fire at the deadline, but considering @@ -1097,9 +1097,9 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) * If the runqueue is no longer available, migrate the * task elsewhere. This necessarily changes rq. */ - lockdep_unpin_lock(&rq->lock, rf.cookie); + lockdep_unpin_lock(__rq_lockp(rq), rf.cookie); rq = dl_task_offline_migration(rq, p); - rf.cookie = lockdep_pin_lock(&rq->lock); + rf.cookie = lockdep_pin_lock(__rq_lockp(rq)); update_rq_clock(rq); /* @@ -1355,10 +1355,10 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) sched_clock_tick(); update_rq_clock(rq); - if (!dl_task(p) || p->state == TASK_DEAD) { + if (!dl_task(p) || READ_ONCE(p->__state) == TASK_DEAD) { struct dl_bw *dl_b = dl_bw_of(task_cpu(p)); - if (p->state == TASK_DEAD && dl_se->dl_non_contending) { + if (READ_ONCE(p->__state) == TASK_DEAD && dl_se->dl_non_contending) { sub_running_bw(&p->dl, dl_rq_of_se(&p->dl)); sub_rq_bw(&p->dl, dl_rq_of_se(&p->dl)); dl_se->dl_non_contending = 0; @@ -1722,7 +1722,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused { struct rq *rq; - if (p->state != TASK_WAKING) + if (READ_ONCE(p->__state) != TASK_WAKING) return; rq = task_rq(p); @@ -1731,7 +1731,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused * from try_to_wake_up(). Hence, p->pi_lock is locked, but * rq->lock is not... So, lock it */ - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); if (p->dl.dl_non_contending) { sub_running_bw(&p->dl, &rq->dl); p->dl.dl_non_contending = 0; @@ -1746,7 +1746,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused put_task_struct(p); } sub_rq_bw(&p->dl, &rq->dl); - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); } static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p) @@ -1852,7 +1852,7 @@ static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq, return rb_entry(left, struct sched_dl_entity, rb_node); } -static struct task_struct *pick_next_task_dl(struct rq *rq) +static struct task_struct *pick_task_dl(struct rq *rq) { struct sched_dl_entity *dl_se; struct dl_rq *dl_rq = &rq->dl; @@ -1864,7 +1864,18 @@ static struct task_struct *pick_next_task_dl(struct rq *rq) dl_se = pick_next_dl_entity(rq, dl_rq); BUG_ON(!dl_se); p = dl_task_of(dl_se); - set_next_task_dl(rq, p, true); + + return p; +} + +static struct task_struct *pick_next_task_dl(struct rq *rq) +{ + struct task_struct *p; + + p = pick_task_dl(rq); + if (p) + set_next_task_dl(rq, p, true); + return p; } @@ -2291,10 +2302,10 @@ skip: double_unlock_balance(this_rq, src_rq); if (push_task) { - raw_spin_unlock(&this_rq->lock); + raw_spin_rq_unlock(this_rq); stop_one_cpu_nowait(src_rq->cpu, push_cpu_stop, push_task, &src_rq->push_work); - raw_spin_lock(&this_rq->lock); + raw_spin_rq_lock(this_rq); } } @@ -2486,6 +2497,8 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) check_preempt_curr_dl(rq, p, 0); else resched_curr(rq); + } else { + update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 0); } } @@ -2539,6 +2552,7 @@ DEFINE_SCHED_CLASS(dl) = { #ifdef CONFIG_SMP .balance = balance_dl, + .pick_task = pick_task_dl, .select_task_rq = select_task_rq_dl, .migrate_task_rq = migrate_task_rq_dl, .set_cpus_allowed = set_cpus_allowed_dl, diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index c5aacbd492a1..0c5ec2776ddf 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -576,7 +576,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock", SPLIT_NS(cfs_rq->exec_clock)); - raw_spin_lock_irqsave(&rq->lock, flags); + raw_spin_rq_lock_irqsave(rq, flags); if (rb_first_cached(&cfs_rq->tasks_timeline)) MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime; last = __pick_last_entity(cfs_rq); @@ -584,7 +584,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) max_vruntime = last->vruntime; min_vruntime = cfs_rq->min_vruntime; rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime; - raw_spin_unlock_irqrestore(&rq->lock, flags); + raw_spin_rq_unlock_irqrestore(rq, flags); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "MIN_vruntime", SPLIT_NS(MIN_vruntime)); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "min_vruntime", diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 23663318fb81..e6d1dd4e9d68 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -268,33 +268,11 @@ const struct sched_class fair_sched_class; */ #ifdef CONFIG_FAIR_GROUP_SCHED -static inline struct task_struct *task_of(struct sched_entity *se) -{ - SCHED_WARN_ON(!entity_is_task(se)); - return container_of(se, struct task_struct, se); -} /* Walk up scheduling entities hierarchy */ #define for_each_sched_entity(se) \ for (; se; se = se->parent) -static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) -{ - return p->se.cfs_rq; -} - -/* runqueue on which this entity is (to be) queued */ -static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) -{ - return se->cfs_rq; -} - -/* runqueue "owned" by this group */ -static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) -{ - return grp->my_q; -} - static inline void cfs_rq_tg_path(struct cfs_rq *cfs_rq, char *path, int len) { if (!path) @@ -455,33 +433,9 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse) #else /* !CONFIG_FAIR_GROUP_SCHED */ -static inline struct task_struct *task_of(struct sched_entity *se) -{ - return container_of(se, struct task_struct, se); -} - #define for_each_sched_entity(se) \ for (; se; se = NULL) -static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) -{ - return &task_rq(p)->cfs; -} - -static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) -{ - struct task_struct *p = task_of(se); - struct rq *rq = task_rq(p); - - return &rq->cfs; -} - -/* runqueue "owned" by this group */ -static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) -{ - return NULL; -} - static inline void cfs_rq_tg_path(struct cfs_rq *cfs_rq, char *path, int len) { if (path) @@ -1039,11 +993,14 @@ update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) if ((flags & DEQUEUE_SLEEP) && entity_is_task(se)) { struct task_struct *tsk = task_of(se); + unsigned int state; - if (tsk->state & TASK_INTERRUPTIBLE) + /* XXX racy against TTWU */ + state = READ_ONCE(tsk->__state); + if (state & TASK_INTERRUPTIBLE) __schedstat_set(se->statistics.sleep_start, rq_clock(rq_of(cfs_rq))); - if (tsk->state & TASK_UNINTERRUPTIBLE) + if (state & TASK_UNINTERRUPTIBLE) __schedstat_set(se->statistics.block_start, rq_clock(rq_of(cfs_rq))); } @@ -1107,7 +1064,7 @@ struct numa_group { static struct numa_group *deref_task_numa_group(struct task_struct *p) { return rcu_dereference_check(p->numa_group, p == current || - (lockdep_is_held(&task_rq(p)->lock) && !READ_ONCE(p->on_cpu))); + (lockdep_is_held(__rq_lockp(task_rq(p))) && !READ_ONCE(p->on_cpu))); } static struct numa_group *deref_curr_numa_group(struct task_struct *p) @@ -3139,7 +3096,7 @@ void reweight_task(struct task_struct *p, int prio) * * tg->weight * grq->load.weight * ge->load.weight = ----------------------------- (1) - * \Sum grq->load.weight + * \Sum grq->load.weight * * Now, because computing that sum is prohibitively expensive to compute (been * there, done that) we approximate it with this average stuff. The average @@ -3153,7 +3110,7 @@ void reweight_task(struct task_struct *p, int prio) * * tg->weight * grq->avg.load_avg * ge->load.weight = ------------------------------ (3) - * tg->load_avg + * tg->load_avg * * Where: tg->load_avg ~= \Sum grq->avg.load_avg * @@ -3169,7 +3126,7 @@ void reweight_task(struct task_struct *p, int prio) * * tg->weight * grq->load.weight * ge->load.weight = ----------------------------- = tg->weight (4) - * grp->load.weight + * grp->load.weight * * That is, the sum collapses because all other CPUs are idle; the UP scenario. * @@ -3188,7 +3145,7 @@ void reweight_task(struct task_struct *p, int prio) * * tg->weight * grq->load.weight * ge->load.weight = ----------------------------- (6) - * tg_load_avg' + * tg_load_avg' * * Where: * @@ -3341,6 +3298,15 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) if (child_cfs_rq_on_list(cfs_rq)) return false; + /* + * _avg must be null when _sum are null because _avg = _sum / divider + * Make sure that rounding and/or propagation of PELT values never + * break this. + */ + SCHED_WARN_ON(cfs_rq->avg.load_avg || + cfs_rq->avg.util_avg || + cfs_rq->avg.runnable_avg); + return true; } @@ -3594,9 +3560,12 @@ update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq load_sum = (s64)se_weight(se) * runnable_sum; load_avg = div_s64(load_sum, divider); + se->avg.load_sum = runnable_sum; + delta = load_avg - se->avg.load_avg; + if (!delta) + return; - se->avg.load_sum = runnable_sum; se->avg.load_avg = load_avg; add_positive(&cfs_rq->avg.load_avg, delta); @@ -4476,6 +4445,8 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) static void set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { + clear_buddies(cfs_rq, se); + /* 'current' is not kept within the tree. */ if (se->on_rq) { /* @@ -4535,7 +4506,7 @@ pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr) * Avoid running the skip buddy, if running something else can * be done without getting too unfair. */ - if (cfs_rq->skip == se) { + if (cfs_rq->skip && cfs_rq->skip == se) { struct sched_entity *second; if (se == curr) { @@ -4562,8 +4533,6 @@ pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr) se = cfs_rq->last; } - clear_buddies(cfs_rq, se); - return se; } @@ -4685,8 +4654,11 @@ static inline u64 sched_cfs_bandwidth_slice(void) */ void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b) { - if (cfs_b->quota != RUNTIME_INF) - cfs_b->runtime = cfs_b->quota; + if (unlikely(cfs_b->quota == RUNTIME_INF)) + return; + + cfs_b->runtime += cfs_b->quota; + cfs_b->runtime = min(cfs_b->runtime, cfs_b->quota + cfs_b->burst); } static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) @@ -5047,6 +5019,9 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, u throttled = !list_empty(&cfs_b->throttled_cfs_rq); cfs_b->nr_periods += overrun; + /* Refill extra burst quota even if cfs_b->idle */ + __refill_cfs_bandwidth_runtime(cfs_b); + /* * idle depends on !throttled (for the case of a large deficit), and if * we're going inactive then everything else can be deferred @@ -5054,8 +5029,6 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, u if (cfs_b->idle && !throttled) goto out_deactivate; - __refill_cfs_bandwidth_runtime(cfs_b); - if (!throttled) { /* mark as potentially idle for the upcoming period */ cfs_b->idle = 1; @@ -5305,6 +5278,7 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) if (new < max_cfs_quota_period) { cfs_b->period = ns_to_ktime(new); cfs_b->quota *= 2; + cfs_b->burst *= 2; pr_warn_ratelimited( "cfs_period_timer[cpu%d]: period too short, scaling up (new cfs_period_us = %lld, cfs_quota_us = %lld)\n", @@ -5336,6 +5310,7 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) cfs_b->runtime = 0; cfs_b->quota = RUNTIME_INF; cfs_b->period = ns_to_ktime(default_cfs_period()); + cfs_b->burst = 0; INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq); hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); @@ -5385,7 +5360,7 @@ static void __maybe_unused update_runtime_enabled(struct rq *rq) { struct task_group *tg; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); rcu_read_lock(); list_for_each_entry_rcu(tg, &task_groups, list) { @@ -5404,7 +5379,7 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq) { struct task_group *tg; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); rcu_read_lock(); list_for_each_entry_rcu(tg, &task_groups, list) { @@ -5992,11 +5967,15 @@ find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this /* Traverse only the allowed CPUs */ for_each_cpu_and(i, sched_group_span(group), p->cpus_ptr) { + struct rq *rq = cpu_rq(i); + + if (!sched_core_cookie_match(rq, p)) + continue; + if (sched_idle_cpu(i)) return i; if (available_idle_cpu(i)) { - struct rq *rq = cpu_rq(i); struct cpuidle_state *idle = idle_get_state(rq); if (idle && idle->exit_latency < min_exit_latency) { /* @@ -6082,9 +6061,10 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p return new_cpu; } -static inline int __select_idle_cpu(int cpu) +static inline int __select_idle_cpu(int cpu, struct task_struct *p) { - if (available_idle_cpu(cpu) || sched_idle_cpu(cpu)) + if ((available_idle_cpu(cpu) || sched_idle_cpu(cpu)) && + sched_cpu_cookie_match(cpu_rq(cpu), p)) return cpu; return -1; @@ -6154,7 +6134,7 @@ static int select_idle_core(struct task_struct *p, int core, struct cpumask *cpu int cpu; if (!static_branch_likely(&sched_smt_present)) - return __select_idle_cpu(core); + return __select_idle_cpu(core, p); for_each_cpu(cpu, cpu_smt_mask(core)) { if (!available_idle_cpu(cpu)) { @@ -6210,7 +6190,7 @@ static inline bool test_idle_cores(int cpu, bool def) static inline int select_idle_core(struct task_struct *p, int core, struct cpumask *cpus, int *idle_cpu) { - return __select_idle_cpu(core); + return __select_idle_cpu(core, p); } static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target) @@ -6229,9 +6209,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool { struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); int i, cpu, idle_cpu = -1, nr = INT_MAX; + struct rq *this_rq = this_rq(); int this = smp_processor_id(); struct sched_domain *this_sd; - u64 time; + u64 time = 0; this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); if (!this_sd) @@ -6241,12 +6222,21 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool if (sched_feat(SIS_PROP) && !has_idle_core) { u64 avg_cost, avg_idle, span_avg; + unsigned long now = jiffies; /* - * Due to large variance we need a large fuzz factor; - * hackbench in particularly is sensitive here. + * If we're busy, the assumption that the last idle period + * predicts the future is flawed; age away the remaining + * predicted idle time. */ - avg_idle = this_rq()->avg_idle / 512; + if (unlikely(this_rq->wake_stamp < now)) { + while (this_rq->wake_stamp < now && this_rq->wake_avg_idle) { + this_rq->wake_stamp++; + this_rq->wake_avg_idle >>= 1; + } + } + + avg_idle = this_rq->wake_avg_idle; avg_cost = this_sd->avg_scan_cost + 1; span_avg = sd->span_weight * avg_idle; @@ -6267,7 +6257,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool } else { if (!--nr) return -1; - idle_cpu = __select_idle_cpu(cpu); + idle_cpu = __select_idle_cpu(cpu, p); if ((unsigned int)idle_cpu < nr_cpumask_bits) break; } @@ -6278,6 +6268,13 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool if (sched_feat(SIS_PROP) && !has_idle_core) { time = cpu_clock(this) - time; + + /* + * Account for the scan cost of wakeups against the average + * idle time. + */ + this_rq->wake_avg_idle -= min(this_rq->wake_avg_idle, time); + update_avg(&this_sd->avg_scan_cost, time); } @@ -6345,6 +6342,11 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) task_util = uclamp_task_util(p); } + /* + * per-cpu select_idle_mask usage + */ + lockdep_assert_irqs_disabled(); + if ((available_idle_cpu(target) || sched_idle_cpu(target)) && asym_fits_capacity(task_util, target)) return target; @@ -6620,8 +6622,11 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) struct cpumask *pd_mask = perf_domain_span(pd); unsigned long cpu_cap = arch_scale_cpu_capacity(cpumask_first(pd_mask)); unsigned long max_util = 0, sum_util = 0; + unsigned long _cpu_cap = cpu_cap; int cpu; + _cpu_cap -= arch_scale_thermal_pressure(cpumask_first(pd_mask)); + /* * The capacity state of CPUs of the current rd can be driven by CPUs * of another rd if they belong to the same pd. So, account for the @@ -6657,8 +6662,10 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) * is already enough to scale the EM reported power * consumption at the (eventually clamped) cpu_capacity. */ - sum_util += effective_cpu_util(cpu, util_running, cpu_cap, - ENERGY_UTIL, NULL); + cpu_util = effective_cpu_util(cpu, util_running, cpu_cap, + ENERGY_UTIL, NULL); + + sum_util += min(cpu_util, _cpu_cap); /* * Performance domain frequency: utilization clamping @@ -6669,10 +6676,10 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) */ cpu_util = effective_cpu_util(cpu, util_freq, cpu_cap, FREQUENCY_UTIL, tsk); - max_util = max(max_util, cpu_util); + max_util = max(max_util, min(cpu_util, _cpu_cap)); } - return em_cpu_energy(pd->em_pd, max_util, sum_util); + return em_cpu_energy(pd->em_pd, max_util, sum_util, _cpu_cap); } /* @@ -6718,15 +6725,15 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) { unsigned long prev_delta = ULONG_MAX, best_delta = ULONG_MAX; struct root_domain *rd = cpu_rq(smp_processor_id())->rd; + int cpu, best_energy_cpu = prev_cpu, target = -1; unsigned long cpu_cap, util, base_energy = 0; - int cpu, best_energy_cpu = prev_cpu; struct sched_domain *sd; struct perf_domain *pd; rcu_read_lock(); pd = rcu_dereference(rd->pd); if (!pd || READ_ONCE(rd->overutilized)) - goto fail; + goto unlock; /* * Energy-aware wake-up happens on the lowest sched_domain starting @@ -6736,7 +6743,9 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) while (sd && !cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) sd = sd->parent; if (!sd) - goto fail; + goto unlock; + + target = prev_cpu; sync_entity_load_avg(&p->se); if (!task_util_est(p)) @@ -6744,13 +6753,10 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) for (; pd; pd = pd->next) { unsigned long cur_delta, spare_cap, max_spare_cap = 0; + bool compute_prev_delta = false; unsigned long base_energy_pd; int max_spare_cap_cpu = -1; - /* Compute the 'base' energy of the pd, without @p */ - base_energy_pd = compute_energy(p, -1, pd); - base_energy += base_energy_pd; - for_each_cpu_and(cpu, perf_domain_span(pd), sched_domain_span(sd)) { if (!cpumask_test_cpu(cpu, p->cpus_ptr)) continue; @@ -6771,26 +6777,40 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) if (!fits_capacity(util, cpu_cap)) continue; - /* Always use prev_cpu as a candidate. */ if (cpu == prev_cpu) { - prev_delta = compute_energy(p, prev_cpu, pd); - prev_delta -= base_energy_pd; - best_delta = min(best_delta, prev_delta); - } - - /* - * Find the CPU with the maximum spare capacity in - * the performance domain - */ - if (spare_cap > max_spare_cap) { + /* Always use prev_cpu as a candidate. */ + compute_prev_delta = true; + } else if (spare_cap > max_spare_cap) { + /* + * Find the CPU with the maximum spare capacity + * in the performance domain. + */ max_spare_cap = spare_cap; max_spare_cap_cpu = cpu; } } - /* Evaluate the energy impact of using this CPU. */ - if (max_spare_cap_cpu >= 0 && max_spare_cap_cpu != prev_cpu) { + if (max_spare_cap_cpu < 0 && !compute_prev_delta) + continue; + + /* Compute the 'base' energy of the pd, without @p */ + base_energy_pd = compute_energy(p, -1, pd); + base_energy += base_energy_pd; + + /* Evaluate the energy impact of using prev_cpu. */ + if (compute_prev_delta) { + prev_delta = compute_energy(p, prev_cpu, pd); + if (prev_delta < base_energy_pd) + goto unlock; + prev_delta -= base_energy_pd; + best_delta = min(best_delta, prev_delta); + } + + /* Evaluate the energy impact of using max_spare_cap_cpu. */ + if (max_spare_cap_cpu >= 0) { cur_delta = compute_energy(p, max_spare_cap_cpu, pd); + if (cur_delta < base_energy_pd) + goto unlock; cur_delta -= base_energy_pd; if (cur_delta < best_delta) { best_delta = cur_delta; @@ -6798,25 +6818,22 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) } } } -unlock: rcu_read_unlock(); /* * Pick the best CPU if prev_cpu cannot be used, or if it saves at * least 6% of the energy used by prev_cpu. */ - if (prev_delta == ULONG_MAX) - return best_energy_cpu; - - if ((prev_delta - best_delta) > ((prev_delta + base_energy) >> 4)) - return best_energy_cpu; + if ((prev_delta == ULONG_MAX) || + (prev_delta - best_delta) > ((prev_delta + base_energy) >> 4)) + target = best_energy_cpu; - return prev_cpu; + return target; -fail: +unlock: rcu_read_unlock(); - return -1; + return target; } /* @@ -6828,8 +6845,6 @@ fail: * certain conditions an idle sibling CPU if the domain has SD_WAKE_AFFINE set. * * Returns the target CPU number. - * - * preempt must be disabled. */ static int select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags) @@ -6842,6 +6857,10 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags) /* SD_flags and WF_flags share the first nibble */ int sd_flag = wake_flags & 0xF; + /* + * required for stable ->cpus_allowed + */ + lockdep_assert_held(&p->pi_lock); if (wake_flags & WF_TTWU) { record_wakee(p); @@ -6906,7 +6925,7 @@ static void migrate_task_rq_fair(struct task_struct *p, int new_cpu) * min_vruntime -- the latter is done by enqueue_entity() when placing * the task on the new runqueue. */ - if (p->state == TASK_WAKING) { + if (READ_ONCE(p->__state) == TASK_WAKING) { struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); u64 min_vruntime; @@ -6931,7 +6950,7 @@ static void migrate_task_rq_fair(struct task_struct *p, int new_cpu) * In case of TASK_ON_RQ_MIGRATING we in fact hold the 'old' * rq->lock and can modify state directly. */ - lockdep_assert_held(&task_rq(p)->lock); + lockdep_assert_rq_held(task_rq(p)); detach_entity_cfs_rq(&p->se); } else { @@ -7135,6 +7154,39 @@ preempt: set_last_buddy(se); } +#ifdef CONFIG_SMP +static struct task_struct *pick_task_fair(struct rq *rq) +{ + struct sched_entity *se; + struct cfs_rq *cfs_rq; + +again: + cfs_rq = &rq->cfs; + if (!cfs_rq->nr_running) + return NULL; + + do { + struct sched_entity *curr = cfs_rq->curr; + + /* When we pick for a remote RQ, we'll not have done put_prev_entity() */ + if (curr) { + if (curr->on_rq) + update_curr(cfs_rq); + else + curr = NULL; + + if (unlikely(check_cfs_rq_runtime(cfs_rq))) + goto again; + } + + se = pick_next_entity(cfs_rq, curr); + cfs_rq = group_cfs_rq(se); + } while (cfs_rq); + + return task_of(se); +} +#endif + struct task_struct * pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { @@ -7558,7 +7610,7 @@ static int task_hot(struct task_struct *p, struct lb_env *env) { s64 delta; - lockdep_assert_held(&env->src_rq->lock); + lockdep_assert_rq_held(env->src_rq); if (p->sched_class != &fair_sched_class) return 0; @@ -7580,6 +7632,14 @@ static int task_hot(struct task_struct *p, struct lb_env *env) if (sysctl_sched_migration_cost == -1) return 1; + + /* + * Don't migrate task if the task's cookie does not match + * with the destination CPU's core cookie. + */ + if (!sched_core_cookie_match(cpu_rq(env->dst_cpu), p)) + return 1; + if (sysctl_sched_migration_cost == 0) return 0; @@ -7656,7 +7716,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) { int tsk_cache_hot; - lockdep_assert_held(&env->src_rq->lock); + lockdep_assert_rq_held(env->src_rq); /* * We do not migrate tasks that are: @@ -7745,7 +7805,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) */ static void detach_task(struct task_struct *p, struct lb_env *env) { - lockdep_assert_held(&env->src_rq->lock); + lockdep_assert_rq_held(env->src_rq); deactivate_task(env->src_rq, p, DEQUEUE_NOCLOCK); set_task_cpu(p, env->dst_cpu); @@ -7761,7 +7821,7 @@ static struct task_struct *detach_one_task(struct lb_env *env) { struct task_struct *p; - lockdep_assert_held(&env->src_rq->lock); + lockdep_assert_rq_held(env->src_rq); list_for_each_entry_reverse(p, &env->src_rq->cfs_tasks, se.group_node) { @@ -7797,7 +7857,7 @@ static int detach_tasks(struct lb_env *env) struct task_struct *p; int detached = 0; - lockdep_assert_held(&env->src_rq->lock); + lockdep_assert_rq_held(env->src_rq); /* * Source run queue has been emptied by another CPU, clear @@ -7927,7 +7987,7 @@ next: */ static void attach_task(struct rq *rq, struct task_struct *p) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); BUG_ON(task_rq(p) != rq); activate_task(rq, p, ENQUEUE_NOCLOCK); @@ -8893,6 +8953,10 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) p->cpus_ptr)) continue; + /* Skip over this group if no cookie matched */ + if (!sched_group_cookie_match(cpu_rq(this_cpu), p, group)) + continue; + local_group = cpumask_test_cpu(this_cpu, sched_group_span(group)); @@ -9821,7 +9885,7 @@ more_balance: if (need_active_balance(&env)) { unsigned long flags; - raw_spin_lock_irqsave(&busiest->lock, flags); + raw_spin_rq_lock_irqsave(busiest, flags); /* * Don't kick the active_load_balance_cpu_stop, @@ -9829,8 +9893,7 @@ more_balance: * moved to this_cpu: */ if (!cpumask_test_cpu(this_cpu, busiest->curr->cpus_ptr)) { - raw_spin_unlock_irqrestore(&busiest->lock, - flags); + raw_spin_rq_unlock_irqrestore(busiest, flags); goto out_one_pinned; } @@ -9847,7 +9910,7 @@ more_balance: busiest->push_cpu = this_cpu; active_balance = 1; } - raw_spin_unlock_irqrestore(&busiest->lock, flags); + raw_spin_rq_unlock_irqrestore(busiest, flags); if (active_balance) { stop_one_cpu_nowait(cpu_of(busiest), @@ -10632,6 +10695,14 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) u64 curr_cost = 0; update_misfit_status(NULL, this_rq); + + /* + * There is a task waiting to run. No need to search for one. + * Return 0; the task will be enqueued when switching to idle. + */ + if (this_rq->ttwu_pending) + return 0; + /* * We must set idle_stamp _before_ calling idle_balance(), such that we * measure the duration of idle_balance() as idle time. @@ -10664,7 +10735,7 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) goto out; } - raw_spin_unlock(&this_rq->lock); + raw_spin_rq_unlock(this_rq); update_blocked_averages(this_cpu); rcu_read_lock(); @@ -10697,12 +10768,13 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) * Stop searching for tasks to pull if there are * now runnable tasks on this rq. */ - if (pulled_task || this_rq->nr_running > 0) + if (pulled_task || this_rq->nr_running > 0 || + this_rq->ttwu_pending) break; } rcu_read_unlock(); - raw_spin_lock(&this_rq->lock); + raw_spin_rq_lock(this_rq); if (curr_cost > this_rq->max_idle_balance_cost) this_rq->max_idle_balance_cost = curr_cost; @@ -10795,6 +10867,119 @@ static void rq_offline_fair(struct rq *rq) #endif /* CONFIG_SMP */ +#ifdef CONFIG_SCHED_CORE +static inline bool +__entity_slice_used(struct sched_entity *se, int min_nr_tasks) +{ + u64 slice = sched_slice(cfs_rq_of(se), se); + u64 rtime = se->sum_exec_runtime - se->prev_sum_exec_runtime; + + return (rtime * min_nr_tasks > slice); +} + +#define MIN_NR_TASKS_DURING_FORCEIDLE 2 +static inline void task_tick_core(struct rq *rq, struct task_struct *curr) +{ + if (!sched_core_enabled(rq)) + return; + + /* + * If runqueue has only one task which used up its slice and + * if the sibling is forced idle, then trigger schedule to + * give forced idle task a chance. + * + * sched_slice() considers only this active rq and it gets the + * whole slice. But during force idle, we have siblings acting + * like a single runqueue and hence we need to consider runnable + * tasks on this CPU and the forced idle CPU. Ideally, we should + * go through the forced idle rq, but that would be a perf hit. + * We can assume that the forced idle CPU has at least + * MIN_NR_TASKS_DURING_FORCEIDLE - 1 tasks and use that to check + * if we need to give up the CPU. + */ + if (rq->core->core_forceidle && rq->cfs.nr_running == 1 && + __entity_slice_used(&curr->se, MIN_NR_TASKS_DURING_FORCEIDLE)) + resched_curr(rq); +} + +/* + * se_fi_update - Update the cfs_rq->min_vruntime_fi in a CFS hierarchy if needed. + */ +static void se_fi_update(struct sched_entity *se, unsigned int fi_seq, bool forceidle) +{ + for_each_sched_entity(se) { + struct cfs_rq *cfs_rq = cfs_rq_of(se); + + if (forceidle) { + if (cfs_rq->forceidle_seq == fi_seq) + break; + cfs_rq->forceidle_seq = fi_seq; + } + + cfs_rq->min_vruntime_fi = cfs_rq->min_vruntime; + } +} + +void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi) +{ + struct sched_entity *se = &p->se; + + if (p->sched_class != &fair_sched_class) + return; + + se_fi_update(se, rq->core->core_forceidle_seq, in_fi); +} + +bool cfs_prio_less(struct task_struct *a, struct task_struct *b, bool in_fi) +{ + struct rq *rq = task_rq(a); + struct sched_entity *sea = &a->se; + struct sched_entity *seb = &b->se; + struct cfs_rq *cfs_rqa; + struct cfs_rq *cfs_rqb; + s64 delta; + + SCHED_WARN_ON(task_rq(b)->core != rq->core); + +#ifdef CONFIG_FAIR_GROUP_SCHED + /* + * Find an se in the hierarchy for tasks a and b, such that the se's + * are immediate siblings. + */ + while (sea->cfs_rq->tg != seb->cfs_rq->tg) { + int sea_depth = sea->depth; + int seb_depth = seb->depth; + + if (sea_depth >= seb_depth) + sea = parent_entity(sea); + if (sea_depth <= seb_depth) + seb = parent_entity(seb); + } + + se_fi_update(sea, rq->core->core_forceidle_seq, in_fi); + se_fi_update(seb, rq->core->core_forceidle_seq, in_fi); + + cfs_rqa = sea->cfs_rq; + cfs_rqb = seb->cfs_rq; +#else + cfs_rqa = &task_rq(a)->cfs; + cfs_rqb = &task_rq(b)->cfs; +#endif + + /* + * Find delta after normalizing se's vruntime with its cfs_rq's + * min_vruntime_fi, which would have been updated in prior calls + * to se_fi_update(). + */ + delta = (s64)(sea->vruntime - seb->vruntime) + + (s64)(cfs_rqb->min_vruntime_fi - cfs_rqa->min_vruntime_fi); + + return delta > 0; +} +#else +static inline void task_tick_core(struct rq *rq, struct task_struct *curr) {} +#endif + /* * scheduler tick hitting a task of our scheduling class. * @@ -10818,6 +11003,8 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) update_misfit_status(curr, rq); update_overutilized_status(task_rq(curr)); + + task_tick_core(rq, curr); } /* @@ -10903,7 +11090,7 @@ static inline bool vruntime_normalized(struct task_struct *p) * waiting for actually being woken up by sched_ttwu_pending(). */ if (!se->sum_exec_runtime || - (p->state == TASK_WAKING && p->sched_remote_wakeup)) + (READ_ONCE(p->__state) == TASK_WAKING && p->sched_remote_wakeup)) return true; return false; @@ -11189,9 +11376,9 @@ void unregister_fair_sched_group(struct task_group *tg) rq = cpu_rq(cpu); - raw_spin_lock_irqsave(&rq->lock, flags); + raw_spin_rq_lock_irqsave(rq, flags); list_del_leaf_cfs_rq(tg->cfs_rq[cpu]); - raw_spin_unlock_irqrestore(&rq->lock, flags); + raw_spin_rq_unlock_irqrestore(rq, flags); } } @@ -11313,6 +11500,7 @@ DEFINE_SCHED_CLASS(fair) = { #ifdef CONFIG_SMP .balance = balance_fair, + .pick_task = pick_task_fair, .select_task_rq = select_task_rq_fair, .migrate_task_rq = migrate_task_rq_fair, diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 7ca3d3d86c2a..912b47aa99d8 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -437,8 +437,16 @@ static void set_next_task_idle(struct rq *rq, struct task_struct *next, bool fir { update_idle_core(rq); schedstat_inc(rq->sched_goidle); + queue_core_balance(rq); } +#ifdef CONFIG_SMP +static struct task_struct *pick_task_idle(struct rq *rq) +{ + return rq->idle; +} +#endif + struct task_struct *pick_next_task_idle(struct rq *rq) { struct task_struct *next = rq->idle; @@ -455,10 +463,10 @@ struct task_struct *pick_next_task_idle(struct rq *rq) static void dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) { - raw_spin_unlock_irq(&rq->lock); + raw_spin_rq_unlock_irq(rq); printk(KERN_ERR "bad: scheduling from the idle thread!\n"); dump_stack(); - raw_spin_lock_irq(&rq->lock); + raw_spin_rq_lock_irq(rq); } /* @@ -506,6 +514,7 @@ DEFINE_SCHED_CLASS(idle) = { #ifdef CONFIG_SMP .balance = balance_idle, + .pick_task = pick_task_idle, .select_task_rq = select_task_rq_idle, .set_cpus_allowed = set_cpus_allowed_common, #endif diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 5a6ea03f9882..7f06eaf12818 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -81,11 +81,9 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) { cpumask_var_t non_housekeeping_mask; cpumask_var_t tmp; - int err; alloc_bootmem_cpumask_var(&non_housekeeping_mask); - err = cpulist_parse(str, non_housekeeping_mask); - if (err < 0 || cpumask_last(non_housekeeping_mask) >= nr_cpu_ids) { + if (cpulist_parse(str, non_housekeeping_mask) < 0) { pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n"); free_bootmem_cpumask_var(non_housekeeping_mask); return 0; diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c index 1c79896f1bc0..954b229868d9 100644 --- a/kernel/sched/loadavg.c +++ b/kernel/sched/loadavg.c @@ -81,7 +81,7 @@ long calc_load_fold_active(struct rq *this_rq, long adjust) long nr_active, delta = 0; nr_active = this_rq->nr_running - adjust; - nr_active += (long)this_rq->nr_uninterruptible; + nr_active += (int)this_rq->nr_uninterruptible; if (nr_active != this_rq->calc_load_active) { delta = nr_active - this_rq->calc_load_active; diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h index cfe94ffd2b38..e06071bf3472 100644 --- a/kernel/sched/pelt.h +++ b/kernel/sched/pelt.h @@ -132,7 +132,7 @@ static inline void update_idle_rq_clock_pelt(struct rq *rq) static inline u64 rq_clock_pelt(struct rq *rq) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); assert_clock_updated(rq); return rq->clock_pelt - rq->lost_idle_time; diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index cc25a3cff41f..58b36d17a09a 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -182,6 +182,8 @@ struct psi_group psi_system = { static void psi_avgs_work(struct work_struct *work); +static void poll_timer_fn(struct timer_list *t); + static void group_init(struct psi_group *group) { int cpu; @@ -201,6 +203,8 @@ static void group_init(struct psi_group *group) memset(group->polling_total, 0, sizeof(group->polling_total)); group->polling_next_update = ULLONG_MAX; group->polling_until = 0; + init_waitqueue_head(&group->poll_wait); + timer_setup(&group->poll_timer, poll_timer_fn, 0); rcu_assign_pointer(group->poll_task, NULL); } @@ -1157,9 +1161,7 @@ struct psi_trigger *psi_trigger_create(struct psi_group *group, return ERR_CAST(task); } atomic_set(&group->poll_wakeup, 0); - init_waitqueue_head(&group->poll_wait); wake_up_process(task); - timer_setup(&group->poll_timer, poll_timer_fn, 0); rcu_assign_pointer(group->poll_task, task); } @@ -1211,6 +1213,7 @@ static void psi_trigger_destroy(struct kref *ref) group->poll_task, lockdep_is_held(&group->trigger_lock)); rcu_assign_pointer(group->poll_task, NULL); + del_timer(&group->poll_timer); } } @@ -1223,17 +1226,14 @@ static void psi_trigger_destroy(struct kref *ref) */ synchronize_rcu(); /* - * Destroy the kworker after releasing trigger_lock to prevent a + * Stop kthread 'psimon' after releasing trigger_lock to prevent a * deadlock while waiting for psi_poll_work to acquire trigger_lock */ if (task_to_destroy) { /* * After the RCU grace period has expired, the worker * can no longer be found through group->poll_task. - * But it might have been already scheduled before - * that - deschedule it cleanly before destroying it. */ - del_timer_sync(&group->poll_timer); kthread_stop(task_to_destroy); } kfree(t); diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index c286e5ba3c94..3daf42a0f462 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -888,7 +888,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) if (skip) continue; - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); update_rq_clock(rq); if (rt_rq->rt_time) { @@ -926,7 +926,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) if (enqueue) sched_rt_rq_enqueue(rt_rq); - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); } if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) @@ -1626,7 +1626,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq) return rt_task_of(rt_se); } -static struct task_struct *pick_next_task_rt(struct rq *rq) +static struct task_struct *pick_task_rt(struct rq *rq) { struct task_struct *p; @@ -1634,7 +1634,17 @@ static struct task_struct *pick_next_task_rt(struct rq *rq) return NULL; p = _pick_next_task_rt(rq); - set_next_task_rt(rq, p, true); + + return p; +} + +static struct task_struct *pick_next_task_rt(struct rq *rq) +{ + struct task_struct *p = pick_task_rt(rq); + + if (p) + set_next_task_rt(rq, p, true); + return p; } @@ -1894,10 +1904,10 @@ retry: */ push_task = get_push_task(rq); if (push_task) { - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); stop_one_cpu_nowait(rq->cpu, push_cpu_stop, push_task, &rq->push_work); - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); } return 0; @@ -2122,10 +2132,10 @@ void rto_push_irq_work_func(struct irq_work *work) * When it gets updated, a check is made if a push is possible. */ if (has_pushable_tasks(rq)) { - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); while (push_rt_task(rq, true)) ; - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); } raw_spin_lock(&rd->rto_lock); @@ -2243,10 +2253,10 @@ skip: double_unlock_balance(this_rq, src_rq); if (push_task) { - raw_spin_unlock(&this_rq->lock); + raw_spin_rq_unlock(this_rq); stop_one_cpu_nowait(src_rq->cpu, push_cpu_stop, push_task, &src_rq->push_work); - raw_spin_lock(&this_rq->lock); + raw_spin_rq_lock(this_rq); } } @@ -2331,13 +2341,20 @@ void __init init_sched_rt_class(void) static void switched_to_rt(struct rq *rq, struct task_struct *p) { /* - * If we are already running, then there's nothing - * that needs to be done. But if we are not running - * we may need to preempt the current running task. - * If that current running task is also an RT task + * If we are running, update the avg_rt tracking, as the running time + * will now on be accounted into the latter. + */ + if (task_current(rq, p)) { + update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); + return; + } + + /* + * If we are not running we may need to preempt the current + * running task. If that current running task is also an RT task * then see if we can move to another run queue. */ - if (task_on_rq_queued(p) && rq->curr != p) { + if (task_on_rq_queued(p)) { #ifdef CONFIG_SMP if (p->nr_cpus_allowed > 1 && rq->rt.overloaded) rt_queue_push_tasks(rq); @@ -2483,6 +2500,7 @@ DEFINE_SCHED_CLASS(rt) = { #ifdef CONFIG_SMP .balance = balance_rt, + .pick_task = pick_task_rt, .select_task_rq = select_task_rq_rt, .set_cpus_allowed = set_cpus_allowed_common, .rq_online = rq_online_rt, diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index a189bec13729..c80d42e9589b 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -366,6 +366,7 @@ struct cfs_bandwidth { ktime_t period; u64 quota; u64 runtime; + u64 burst; s64 hierarchical_quota; u8 idle; @@ -526,6 +527,11 @@ struct cfs_rq { u64 exec_clock; u64 min_vruntime; +#ifdef CONFIG_SCHED_CORE + unsigned int forceidle_seq; + u64 min_vruntime_fi; +#endif + #ifndef CONFIG_64BIT u64 min_vruntime_copy; #endif @@ -631,8 +637,8 @@ struct rt_rq { } highest_prio; #endif #ifdef CONFIG_SMP - unsigned long rt_nr_migratory; - unsigned long rt_nr_total; + unsigned int rt_nr_migratory; + unsigned int rt_nr_total; int overloaded; struct plist_head pushable_tasks; @@ -646,7 +652,7 @@ struct rt_rq { raw_spinlock_t rt_runtime_lock; #ifdef CONFIG_RT_GROUP_SCHED - unsigned long rt_nr_boosted; + unsigned int rt_nr_boosted; struct rq *rq; struct task_group *tg; @@ -663,7 +669,7 @@ struct dl_rq { /* runqueue is an rbtree, ordered by deadline */ struct rb_root_cached root; - unsigned long dl_nr_running; + unsigned int dl_nr_running; #ifdef CONFIG_SMP /* @@ -677,7 +683,7 @@ struct dl_rq { u64 next; } earliest_dl; - unsigned long dl_nr_migratory; + unsigned int dl_nr_migratory; int overloaded; /* @@ -905,7 +911,7 @@ DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); */ struct rq { /* runqueue lock: */ - raw_spinlock_t lock; + raw_spinlock_t __lock; /* * nr_running and cpu_load should be in the same cacheline because @@ -955,7 +961,7 @@ struct rq { * one CPU and if it got migrated afterwards it may decrease * it on another CPU. Always updated under the runqueue lock: */ - unsigned long nr_uninterruptible; + unsigned int nr_uninterruptible; struct task_struct __rcu *curr; struct task_struct *idle; @@ -1017,6 +1023,9 @@ struct rq { u64 idle_stamp; u64 avg_idle; + unsigned long wake_stamp; + u64 wake_avg_idle; + /* This is used to determine avg_idle's max value */ u64 max_idle_balance_cost; @@ -1075,6 +1084,22 @@ struct rq { #endif unsigned int push_busy; struct cpu_stop_work push_work; + +#ifdef CONFIG_SCHED_CORE + /* per rq */ + struct rq *core; + struct task_struct *core_pick; + unsigned int core_enabled; + unsigned int core_sched_seq; + struct rb_root core_tree; + + /* shared state */ + unsigned int core_task_seq; + unsigned int core_pick_seq; + unsigned long core_cookie; + unsigned char core_forceidle; + unsigned int core_forceidle_seq; +#endif }; #ifdef CONFIG_FAIR_GROUP_SCHED @@ -1113,6 +1138,206 @@ static inline bool is_migration_disabled(struct task_struct *p) #endif } +struct sched_group; +#ifdef CONFIG_SCHED_CORE +static inline struct cpumask *sched_group_span(struct sched_group *sg); + +DECLARE_STATIC_KEY_FALSE(__sched_core_enabled); + +static inline bool sched_core_enabled(struct rq *rq) +{ + return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled; +} + +static inline bool sched_core_disabled(void) +{ + return !static_branch_unlikely(&__sched_core_enabled); +} + +/* + * Be careful with this function; not for general use. The return value isn't + * stable unless you actually hold a relevant rq->__lock. + */ +static inline raw_spinlock_t *rq_lockp(struct rq *rq) +{ + if (sched_core_enabled(rq)) + return &rq->core->__lock; + + return &rq->__lock; +} + +static inline raw_spinlock_t *__rq_lockp(struct rq *rq) +{ + if (rq->core_enabled) + return &rq->core->__lock; + + return &rq->__lock; +} + +bool cfs_prio_less(struct task_struct *a, struct task_struct *b, bool fi); + +/* + * Helpers to check if the CPU's core cookie matches with the task's cookie + * when core scheduling is enabled. + * A special case is that the task's cookie always matches with CPU's core + * cookie if the CPU is in an idle core. + */ +static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) +{ + /* Ignore cookie match if core scheduler is not enabled on the CPU. */ + if (!sched_core_enabled(rq)) + return true; + + return rq->core->core_cookie == p->core_cookie; +} + +static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) +{ + bool idle_core = true; + int cpu; + + /* Ignore cookie match if core scheduler is not enabled on the CPU. */ + if (!sched_core_enabled(rq)) + return true; + + for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) { + if (!available_idle_cpu(cpu)) { + idle_core = false; + break; + } + } + + /* + * A CPU in an idle core is always the best choice for tasks with + * cookies. + */ + return idle_core || rq->core->core_cookie == p->core_cookie; +} + +static inline bool sched_group_cookie_match(struct rq *rq, + struct task_struct *p, + struct sched_group *group) +{ + int cpu; + + /* Ignore cookie match if core scheduler is not enabled on the CPU. */ + if (!sched_core_enabled(rq)) + return true; + + for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) { + if (sched_core_cookie_match(rq, p)) + return true; + } + return false; +} + +extern void queue_core_balance(struct rq *rq); + +static inline bool sched_core_enqueued(struct task_struct *p) +{ + return !RB_EMPTY_NODE(&p->core_node); +} + +extern void sched_core_enqueue(struct rq *rq, struct task_struct *p); +extern void sched_core_dequeue(struct rq *rq, struct task_struct *p); + +extern void sched_core_get(void); +extern void sched_core_put(void); + +extern unsigned long sched_core_alloc_cookie(void); +extern void sched_core_put_cookie(unsigned long cookie); +extern unsigned long sched_core_get_cookie(unsigned long cookie); +extern unsigned long sched_core_update_cookie(struct task_struct *p, unsigned long cookie); + +#else /* !CONFIG_SCHED_CORE */ + +static inline bool sched_core_enabled(struct rq *rq) +{ + return false; +} + +static inline bool sched_core_disabled(void) +{ + return true; +} + +static inline raw_spinlock_t *rq_lockp(struct rq *rq) +{ + return &rq->__lock; +} + +static inline raw_spinlock_t *__rq_lockp(struct rq *rq) +{ + return &rq->__lock; +} + +static inline void queue_core_balance(struct rq *rq) +{ +} + +static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) +{ + return true; +} + +static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) +{ + return true; +} + +static inline bool sched_group_cookie_match(struct rq *rq, + struct task_struct *p, + struct sched_group *group) +{ + return true; +} +#endif /* CONFIG_SCHED_CORE */ + +static inline void lockdep_assert_rq_held(struct rq *rq) +{ + lockdep_assert_held(__rq_lockp(rq)); +} + +extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); +extern bool raw_spin_rq_trylock(struct rq *rq); +extern void raw_spin_rq_unlock(struct rq *rq); + +static inline void raw_spin_rq_lock(struct rq *rq) +{ + raw_spin_rq_lock_nested(rq, 0); +} + +static inline void raw_spin_rq_lock_irq(struct rq *rq) +{ + local_irq_disable(); + raw_spin_rq_lock(rq); +} + +static inline void raw_spin_rq_unlock_irq(struct rq *rq) +{ + raw_spin_rq_unlock(rq); + local_irq_enable(); +} + +static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq) +{ + unsigned long flags; + local_irq_save(flags); + raw_spin_rq_lock(rq); + return flags; +} + +static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags) +{ + raw_spin_rq_unlock(rq); + local_irq_restore(flags); +} + +#define raw_spin_rq_lock_irqsave(rq, flags) \ +do { \ + flags = _raw_spin_rq_lock_irqsave(rq); \ +} while (0) + #ifdef CONFIG_SCHED_SMT extern void __update_idle_core(struct rq *rq); @@ -1134,6 +1359,57 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); #define cpu_curr(cpu) (cpu_rq(cpu)->curr) #define raw_rq() raw_cpu_ptr(&runqueues) +#ifdef CONFIG_FAIR_GROUP_SCHED +static inline struct task_struct *task_of(struct sched_entity *se) +{ + SCHED_WARN_ON(!entity_is_task(se)); + return container_of(se, struct task_struct, se); +} + +static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) +{ + return p->se.cfs_rq; +} + +/* runqueue on which this entity is (to be) queued */ +static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) +{ + return se->cfs_rq; +} + +/* runqueue "owned" by this group */ +static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) +{ + return grp->my_q; +} + +#else + +static inline struct task_struct *task_of(struct sched_entity *se) +{ + return container_of(se, struct task_struct, se); +} + +static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) +{ + return &task_rq(p)->cfs; +} + +static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) +{ + struct task_struct *p = task_of(se); + struct rq *rq = task_rq(p); + + return &rq->cfs; +} + +/* runqueue "owned" by this group */ +static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) +{ + return NULL; +} +#endif + extern void update_rq_clock(struct rq *rq); static inline u64 __rq_clock_broken(struct rq *rq) @@ -1179,7 +1455,7 @@ static inline void assert_clock_updated(struct rq *rq) static inline u64 rq_clock(struct rq *rq) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); assert_clock_updated(rq); return rq->clock; @@ -1187,7 +1463,7 @@ static inline u64 rq_clock(struct rq *rq) static inline u64 rq_clock_task(struct rq *rq) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); assert_clock_updated(rq); return rq->clock_task; @@ -1213,7 +1489,7 @@ static inline u64 rq_clock_thermal(struct rq *rq) static inline void rq_clock_skip_update(struct rq *rq) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); rq->clock_update_flags |= RQCF_REQ_SKIP; } @@ -1223,7 +1499,7 @@ static inline void rq_clock_skip_update(struct rq *rq) */ static inline void rq_clock_cancel_skipupdate(struct rq *rq) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); rq->clock_update_flags &= ~RQCF_REQ_SKIP; } @@ -1254,7 +1530,7 @@ extern struct callback_head balance_push_callback; */ static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) { - rf->cookie = lockdep_pin_lock(&rq->lock); + rf->cookie = lockdep_pin_lock(__rq_lockp(rq)); #ifdef CONFIG_SCHED_DEBUG rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); @@ -1272,12 +1548,12 @@ static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) rf->clock_update_flags = RQCF_UPDATED; #endif - lockdep_unpin_lock(&rq->lock, rf->cookie); + lockdep_unpin_lock(__rq_lockp(rq), rf->cookie); } static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) { - lockdep_repin_lock(&rq->lock, rf->cookie); + lockdep_repin_lock(__rq_lockp(rq), rf->cookie); #ifdef CONFIG_SCHED_DEBUG /* @@ -1298,7 +1574,7 @@ static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); } static inline void @@ -1307,7 +1583,7 @@ task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) __releases(p->pi_lock) { rq_unpin_lock(rq, rf); - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); } @@ -1315,7 +1591,7 @@ static inline void rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { - raw_spin_lock_irqsave(&rq->lock, rf->flags); + raw_spin_rq_lock_irqsave(rq, rf->flags); rq_pin_lock(rq, rf); } @@ -1323,7 +1599,7 @@ static inline void rq_lock_irq(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { - raw_spin_lock_irq(&rq->lock); + raw_spin_rq_lock_irq(rq); rq_pin_lock(rq, rf); } @@ -1331,7 +1607,7 @@ static inline void rq_lock(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); rq_pin_lock(rq, rf); } @@ -1339,7 +1615,7 @@ static inline void rq_relock(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { - raw_spin_lock(&rq->lock); + raw_spin_rq_lock(rq); rq_repin_lock(rq, rf); } @@ -1348,7 +1624,7 @@ rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); - raw_spin_unlock_irqrestore(&rq->lock, rf->flags); + raw_spin_rq_unlock_irqrestore(rq, rf->flags); } static inline void @@ -1356,7 +1632,7 @@ rq_unlock_irq(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); - raw_spin_unlock_irq(&rq->lock); + raw_spin_rq_unlock_irq(rq); } static inline void @@ -1364,7 +1640,7 @@ rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); - raw_spin_unlock(&rq->lock); + raw_spin_rq_unlock(rq); } static inline struct rq * @@ -1429,7 +1705,7 @@ queue_balance_callback(struct rq *rq, struct callback_head *head, void (*func)(struct rq *rq)) { - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); if (unlikely(head->next || rq->balance_callback == &balance_push_callback)) return; @@ -1844,6 +2120,9 @@ struct sched_class { #ifdef CONFIG_SMP int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags); + + struct task_struct * (*pick_task)(struct rq *rq); + void (*migrate_task_rq)(struct task_struct *p, int new_cpu); void (*task_woken)(struct rq *this_rq, struct task_struct *task); @@ -1893,7 +2172,6 @@ static inline void put_prev_task(struct rq *rq, struct task_struct *prev) static inline void set_next_task(struct rq *rq, struct task_struct *next) { - WARN_ON_ONCE(rq->curr != next); next->sched_class->set_next_task(rq, next, false); } @@ -1969,7 +2247,7 @@ static inline struct task_struct *get_push_task(struct rq *rq) { struct task_struct *p = rq->curr; - lockdep_assert_held(&rq->lock); + lockdep_assert_rq_held(rq); if (rq->push_busy) return NULL; @@ -2181,10 +2459,38 @@ unsigned long arch_scale_freq_capacity(int cpu) } #endif + #ifdef CONFIG_SMP -#ifdef CONFIG_PREEMPTION -static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); +static inline bool rq_order_less(struct rq *rq1, struct rq *rq2) +{ +#ifdef CONFIG_SCHED_CORE + /* + * In order to not have {0,2},{1,3} turn into into an AB-BA, + * order by core-id first and cpu-id second. + * + * Notably: + * + * double_rq_lock(0,3); will take core-0, core-1 lock + * double_rq_lock(1,2); will take core-1, core-0 lock + * + * when only cpu-id is considered. + */ + if (rq1->core->cpu < rq2->core->cpu) + return true; + if (rq1->core->cpu > rq2->core->cpu) + return false; + + /* + * __sched_core_flip() relies on SMT having cpu-id lock order. + */ +#endif + return rq1->cpu < rq2->cpu; +} + +extern void double_rq_lock(struct rq *rq1, struct rq *rq2); + +#ifdef CONFIG_PREEMPTION /* * fair double_lock_balance: Safely acquires both rq->locks in a fair @@ -2199,7 +2505,7 @@ static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) __acquires(busiest->lock) __acquires(this_rq->lock) { - raw_spin_unlock(&this_rq->lock); + raw_spin_rq_unlock(this_rq); double_rq_lock(this_rq, busiest); return 1; @@ -2218,20 +2524,21 @@ static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) __acquires(busiest->lock) __acquires(this_rq->lock) { - int ret = 0; - - if (unlikely(!raw_spin_trylock(&busiest->lock))) { - if (busiest < this_rq) { - raw_spin_unlock(&this_rq->lock); - raw_spin_lock(&busiest->lock); - raw_spin_lock_nested(&this_rq->lock, - SINGLE_DEPTH_NESTING); - ret = 1; - } else - raw_spin_lock_nested(&busiest->lock, - SINGLE_DEPTH_NESTING); + if (__rq_lockp(this_rq) == __rq_lockp(busiest)) + return 0; + + if (likely(raw_spin_rq_trylock(busiest))) + return 0; + + if (rq_order_less(this_rq, busiest)) { + raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING); + return 0; } - return ret; + + raw_spin_rq_unlock(this_rq); + double_rq_lock(this_rq, busiest); + + return 1; } #endif /* CONFIG_PREEMPTION */ @@ -2241,11 +2548,7 @@ static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) */ static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) { - if (unlikely(!irqs_disabled())) { - /* printk() doesn't work well under rq->lock */ - raw_spin_unlock(&this_rq->lock); - BUG_ON(1); - } + lockdep_assert_irqs_disabled(); return _double_lock_balance(this_rq, busiest); } @@ -2253,8 +2556,9 @@ static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) __releases(busiest->lock) { - raw_spin_unlock(&busiest->lock); - lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); + if (__rq_lockp(this_rq) != __rq_lockp(busiest)) + raw_spin_rq_unlock(busiest); + lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_); } static inline void double_lock(spinlock_t *l1, spinlock_t *l2) @@ -2285,31 +2589,6 @@ static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) } /* - * double_rq_lock - safely lock two runqueues - * - * Note this does not disable interrupts like task_rq_lock, - * you need to do so manually before calling. - */ -static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) - __acquires(rq1->lock) - __acquires(rq2->lock) -{ - BUG_ON(!irqs_disabled()); - if (rq1 == rq2) { - raw_spin_lock(&rq1->lock); - __acquire(rq2->lock); /* Fake it out ;) */ - } else { - if (rq1 < rq2) { - raw_spin_lock(&rq1->lock); - raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); - } else { - raw_spin_lock(&rq2->lock); - raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); - } - } -} - -/* * double_rq_unlock - safely unlock two runqueues * * Note this does not restore interrupts like task_rq_unlock, @@ -2319,11 +2598,11 @@ static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) __releases(rq1->lock) __releases(rq2->lock) { - raw_spin_unlock(&rq1->lock); - if (rq1 != rq2) - raw_spin_unlock(&rq2->lock); + if (__rq_lockp(rq1) != __rq_lockp(rq2)) + raw_spin_rq_unlock(rq2); else __release(rq2->lock); + raw_spin_rq_unlock(rq1); } extern void set_rq_online (struct rq *rq); @@ -2344,7 +2623,7 @@ static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) { BUG_ON(!irqs_disabled()); BUG_ON(rq1 != rq2); - raw_spin_lock(&rq1->lock); + raw_spin_rq_lock(rq1); __acquire(rq2->lock); /* Fake it out ;) */ } @@ -2359,7 +2638,7 @@ static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) __releases(rq2->lock) { BUG_ON(rq1 != rq2); - raw_spin_unlock(&rq1->lock); + raw_spin_rq_unlock(rq1); __release(rq2->lock); } diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index dc218e9f4558..d8f8eb0c655b 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -25,7 +25,7 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta) } static inline void -rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) +rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) { if (rq) rq->rq_sched_info.run_delay += delta; @@ -42,7 +42,7 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) #else /* !CONFIG_SCHEDSTATS: */ static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { } -static inline void rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) { } +static inline void rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) { } static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { } # define schedstat_enabled() 0 # define __schedstat_inc(var) do { } while (0) @@ -150,29 +150,24 @@ static inline void psi_sched_switch(struct task_struct *prev, #endif /* CONFIG_PSI */ #ifdef CONFIG_SCHED_INFO -static inline void sched_info_reset_dequeued(struct task_struct *t) -{ - t->sched_info.last_queued = 0; -} - /* * We are interested in knowing how long it was from the *first* time a * task was queued to the time that it finally hit a CPU, we call this routine * from dequeue_task() to account for possible rq->clock skew across CPUs. The * delta taken on each CPU would annul the skew. */ -static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t) +static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t) { - unsigned long long now = rq_clock(rq), delta = 0; + unsigned long long delta = 0; - if (sched_info_on()) { - if (t->sched_info.last_queued) - delta = now - t->sched_info.last_queued; - } - sched_info_reset_dequeued(t); + if (!t->sched_info.last_queued) + return; + + delta = rq_clock(rq) - t->sched_info.last_queued; + t->sched_info.last_queued = 0; t->sched_info.run_delay += delta; - rq_sched_info_dequeued(rq, delta); + rq_sched_info_dequeue(rq, delta); } /* @@ -182,11 +177,14 @@ static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t) */ static void sched_info_arrive(struct rq *rq, struct task_struct *t) { - unsigned long long now = rq_clock(rq), delta = 0; + unsigned long long now, delta = 0; + + if (!t->sched_info.last_queued) + return; - if (t->sched_info.last_queued) - delta = now - t->sched_info.last_queued; - sched_info_reset_dequeued(t); + now = rq_clock(rq); + delta = now - t->sched_info.last_queued; + t->sched_info.last_queued = 0; t->sched_info.run_delay += delta; t->sched_info.last_arrival = now; t->sched_info.pcount++; @@ -197,14 +195,12 @@ static void sched_info_arrive(struct rq *rq, struct task_struct *t) /* * This function is only called from enqueue_task(), but also only updates * the timestamp if it is already not set. It's assumed that - * sched_info_dequeued() will clear that stamp when appropriate. + * sched_info_dequeue() will clear that stamp when appropriate. */ -static inline void sched_info_queued(struct rq *rq, struct task_struct *t) +static inline void sched_info_enqueue(struct rq *rq, struct task_struct *t) { - if (sched_info_on()) { - if (!t->sched_info.last_queued) - t->sched_info.last_queued = rq_clock(rq); - } + if (!t->sched_info.last_queued) + t->sched_info.last_queued = rq_clock(rq); } /* @@ -212,7 +208,7 @@ static inline void sched_info_queued(struct rq *rq, struct task_struct *t) * due, typically, to expiring its time slice (this may also be called when * switching to the idle task). Now we can calculate how long we ran. * Also, if the process is still in the TASK_RUNNING state, call - * sched_info_queued() to mark that it has now again started waiting on + * sched_info_enqueue() to mark that it has now again started waiting on * the runqueue. */ static inline void sched_info_depart(struct rq *rq, struct task_struct *t) @@ -221,8 +217,8 @@ static inline void sched_info_depart(struct rq *rq, struct task_struct *t) rq_sched_info_depart(rq, delta); - if (t->state == TASK_RUNNING) - sched_info_queued(rq, t); + if (task_is_running(t)) + sched_info_enqueue(rq, t); } /* @@ -231,7 +227,7 @@ static inline void sched_info_depart(struct rq *rq, struct task_struct *t) * the idle task.) We are only called when prev != next. */ static inline void -__sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) +sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) { /* * prev now departs the CPU. It's not interesting to record @@ -245,18 +241,8 @@ __sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct sched_info_arrive(rq, next); } -static inline void -sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) -{ - if (sched_info_on()) - __sched_info_switch(rq, prev, next); -} - #else /* !CONFIG_SCHED_INFO: */ -# define sched_info_queued(rq, t) do { } while (0) -# define sched_info_reset_dequeued(t) do { } while (0) -# define sched_info_dequeued(rq, t) do { } while (0) -# define sched_info_depart(rq, t) do { } while (0) -# define sched_info_arrive(rq, next) do { } while (0) +# define sched_info_enqueue(rq, t) do { } while (0) +# define sched_info_dequeue(rq, t) do { } while (0) # define sched_info_switch(rq, t, next) do { } while (0) #endif /* CONFIG_SCHED_INFO */ diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c index 55f39125c0e1..f988ebe3febb 100644 --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -34,15 +34,24 @@ static void set_next_task_stop(struct rq *rq, struct task_struct *stop, bool fir stop->se.exec_start = rq_clock_task(rq); } -static struct task_struct *pick_next_task_stop(struct rq *rq) +static struct task_struct *pick_task_stop(struct rq *rq) { if (!sched_stop_runnable(rq)) return NULL; - set_next_task_stop(rq, rq->stop, true); return rq->stop; } +static struct task_struct *pick_next_task_stop(struct rq *rq) +{ + struct task_struct *p = pick_task_stop(rq); + + if (p) + set_next_task_stop(rq, p, true); + + return p; +} + static void enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags) { @@ -123,6 +132,7 @@ DEFINE_SCHED_CLASS(stop) = { #ifdef CONFIG_SMP .balance = balance_stop, + .pick_task = pick_task_stop, .select_task_rq = select_task_rq_stop, .set_cpus_allowed = set_cpus_allowed_common, #endif diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 55a0a243e871..b77ad49dc14f 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -467,7 +467,7 @@ void rq_attach_root(struct rq *rq, struct root_domain *rd) struct root_domain *old_rd = NULL; unsigned long flags; - raw_spin_lock_irqsave(&rq->lock, flags); + raw_spin_rq_lock_irqsave(rq, flags); if (rq->rd) { old_rd = rq->rd; @@ -493,7 +493,7 @@ void rq_attach_root(struct rq *rq, struct root_domain *rd) if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) set_rq_online(rq); - raw_spin_unlock_irqrestore(&rq->lock, flags); + raw_spin_rq_unlock_irqrestore(rq, flags); if (old_rd) call_rcu(&old_rd->rcu, free_rootdomain); @@ -675,7 +675,7 @@ static void update_top_cache_domain(int cpu) sd = highest_flag_domain(cpu, SD_ASYM_PACKING); rcu_assign_pointer(per_cpu(sd_asym_packing, cpu), sd); - sd = lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY); + sd = lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY_FULL); rcu_assign_pointer(per_cpu(sd_asym_cpucapacity, cpu), sd); } @@ -1267,6 +1267,116 @@ next: } /* + * Asymmetric CPU capacity bits + */ +struct asym_cap_data { + struct list_head link; + unsigned long capacity; + unsigned long cpus[]; +}; + +/* + * Set of available CPUs grouped by their corresponding capacities + * Each list entry contains a CPU mask reflecting CPUs that share the same + * capacity. + * The lifespan of data is unlimited. + */ +static LIST_HEAD(asym_cap_list); + +#define cpu_capacity_span(asym_data) to_cpumask((asym_data)->cpus) + +/* + * Verify whether there is any CPU capacity asymmetry in a given sched domain. + * Provides sd_flags reflecting the asymmetry scope. + */ +static inline int +asym_cpu_capacity_classify(const struct cpumask *sd_span, + const struct cpumask *cpu_map) +{ + struct asym_cap_data *entry; + int count = 0, miss = 0; + + /* + * Count how many unique CPU capacities this domain spans across + * (compare sched_domain CPUs mask with ones representing available + * CPUs capacities). Take into account CPUs that might be offline: + * skip those. + */ + list_for_each_entry(entry, &asym_cap_list, link) { + if (cpumask_intersects(sd_span, cpu_capacity_span(entry))) + ++count; + else if (cpumask_intersects(cpu_map, cpu_capacity_span(entry))) + ++miss; + } + + WARN_ON_ONCE(!count && !list_empty(&asym_cap_list)); + + /* No asymmetry detected */ + if (count < 2) + return 0; + /* Some of the available CPU capacity values have not been detected */ + if (miss) + return SD_ASYM_CPUCAPACITY; + + /* Full asymmetry */ + return SD_ASYM_CPUCAPACITY | SD_ASYM_CPUCAPACITY_FULL; + +} + +static inline void asym_cpu_capacity_update_data(int cpu) +{ + unsigned long capacity = arch_scale_cpu_capacity(cpu); + struct asym_cap_data *entry = NULL; + + list_for_each_entry(entry, &asym_cap_list, link) { + if (capacity == entry->capacity) + goto done; + } + + entry = kzalloc(sizeof(*entry) + cpumask_size(), GFP_KERNEL); + if (WARN_ONCE(!entry, "Failed to allocate memory for asymmetry data\n")) + return; + entry->capacity = capacity; + list_add(&entry->link, &asym_cap_list); +done: + __cpumask_set_cpu(cpu, cpu_capacity_span(entry)); +} + +/* + * Build-up/update list of CPUs grouped by their capacities + * An update requires explicit request to rebuild sched domains + * with state indicating CPU topology changes. + */ +static void asym_cpu_capacity_scan(void) +{ + struct asym_cap_data *entry, *next; + int cpu; + + list_for_each_entry(entry, &asym_cap_list, link) + cpumask_clear(cpu_capacity_span(entry)); + + for_each_cpu_and(cpu, cpu_possible_mask, housekeeping_cpumask(HK_FLAG_DOMAIN)) + asym_cpu_capacity_update_data(cpu); + + list_for_each_entry_safe(entry, next, &asym_cap_list, link) { + if (cpumask_empty(cpu_capacity_span(entry))) { + list_del(&entry->link); + kfree(entry); + } + } + + /* + * Only one capacity value has been detected i.e. this system is symmetric. + * No need to keep this data around. + */ + if (list_is_singular(&asym_cap_list)) { + entry = list_first_entry(&asym_cap_list, typeof(*entry), link); + list_del(&entry->link); + kfree(entry); + } +} + +/* * Initializers for schedule domains * Non-inlined to reduce accumulated stack pressure in build_sched_domains() */ @@ -1399,11 +1509,12 @@ int __read_mostly node_reclaim_distance = RECLAIM_DISTANCE; static struct sched_domain * sd_init(struct sched_domain_topology_level *tl, const struct cpumask *cpu_map, - struct sched_domain *child, int dflags, int cpu) + struct sched_domain *child, int cpu) { struct sd_data *sdd = &tl->data; struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); int sd_id, sd_weight, sd_flags = 0; + struct cpumask *sd_span; #ifdef CONFIG_NUMA /* @@ -1420,9 +1531,6 @@ sd_init(struct sched_domain_topology_level *tl, "wrong sd_flags in topology description\n")) sd_flags &= TOPOLOGY_SD_FLAGS; - /* Apply detected topology flags */ - sd_flags |= dflags; - *sd = (struct sched_domain){ .min_interval = sd_weight, .max_interval = 2*sd_weight, @@ -1454,13 +1562,19 @@ sd_init(struct sched_domain_topology_level *tl, #endif }; - cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); - sd_id = cpumask_first(sched_domain_span(sd)); + sd_span = sched_domain_span(sd); + cpumask_and(sd_span, cpu_map, tl->mask(cpu)); + sd_id = cpumask_first(sd_span); + + sd->flags |= asym_cpu_capacity_classify(sd_span, cpu_map); + + WARN_ONCE((sd->flags & (SD_SHARE_CPUCAPACITY | SD_ASYM_CPUCAPACITY)) == + (SD_SHARE_CPUCAPACITY | SD_ASYM_CPUCAPACITY), + "CPU capacity asymmetry not supported on SMT\n"); /* * Convert topological properties into behaviour. */ - /* Don't attempt to spread across CPUs of different capacities. */ if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child) sd->child->flags &= ~SD_PREFER_SIBLING; @@ -1926,9 +2040,9 @@ static void __sdt_free(const struct cpumask *cpu_map) static struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *child, int dflags, int cpu) + struct sched_domain *child, int cpu) { - struct sched_domain *sd = sd_init(tl, cpu_map, child, dflags, cpu); + struct sched_domain *sd = sd_init(tl, cpu_map, child, cpu); if (child) { sd->level = child->level + 1; @@ -1991,65 +2105,6 @@ static bool topology_span_sane(struct sched_domain_topology_level *tl, } /* - * Find the sched_domain_topology_level where all CPU capacities are visible - * for all CPUs. - */ -static struct sched_domain_topology_level -*asym_cpu_capacity_level(const struct cpumask *cpu_map) -{ - int i, j, asym_level = 0; - bool asym = false; - struct sched_domain_topology_level *tl, *asym_tl = NULL; - unsigned long cap; - - /* Is there any asymmetry? */ - cap = arch_scale_cpu_capacity(cpumask_first(cpu_map)); - - for_each_cpu(i, cpu_map) { - if (arch_scale_cpu_capacity(i) != cap) { - asym = true; - break; - } - } - - if (!asym) - return NULL; - - /* - * Examine topology from all CPU's point of views to detect the lowest - * sched_domain_topology_level where a highest capacity CPU is visible - * to everyone. - */ - for_each_cpu(i, cpu_map) { - unsigned long max_capacity = arch_scale_cpu_capacity(i); - int tl_id = 0; - - for_each_sd_topology(tl) { - if (tl_id < asym_level) - goto next_level; - - for_each_cpu_and(j, tl->mask(i), cpu_map) { - unsigned long capacity; - - capacity = arch_scale_cpu_capacity(j); - - if (capacity <= max_capacity) - continue; - - max_capacity = capacity; - asym_level = tl_id; - asym_tl = tl; - } -next_level: - tl_id++; - } - } - - return asym_tl; -} - - -/* * Build sched domains for a given set of CPUs and attach the sched domains * to the individual CPUs */ @@ -2061,7 +2116,6 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att struct s_data d; struct rq *rq = NULL; int i, ret = -ENOMEM; - struct sched_domain_topology_level *tl_asym; bool has_asym = false; if (WARN_ON(cpumask_empty(cpu_map))) @@ -2071,24 +2125,19 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att if (alloc_state != sa_rootdomain) goto error; - tl_asym = asym_cpu_capacity_level(cpu_map); - /* Set up domains for CPUs specified by the cpu_map: */ for_each_cpu(i, cpu_map) { struct sched_domain_topology_level *tl; - int dflags = 0; sd = NULL; for_each_sd_topology(tl) { - if (tl == tl_asym) { - dflags |= SD_ASYM_CPUCAPACITY; - has_asym = true; - } if (WARN_ON(!topology_span_sane(tl, cpu_map, i))) goto error; - sd = build_sched_domain(tl, cpu_map, attr, sd, dflags, i); + sd = build_sched_domain(tl, cpu_map, attr, sd, i); + + has_asym |= sd->flags & SD_ASYM_CPUCAPACITY; if (tl == sched_domain_topology) *per_cpu_ptr(d.sd, i) = sd; @@ -2217,6 +2266,7 @@ int sched_init_domains(const struct cpumask *cpu_map) zalloc_cpumask_var(&fallback_doms, GFP_KERNEL); arch_update_cpu_topology(); + asym_cpu_capacity_scan(); ndoms_cur = 1; doms_cur = alloc_sched_domains(ndoms_cur); if (!doms_cur) @@ -2299,6 +2349,9 @@ void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[], /* Let the architecture update CPU core mappings: */ new_topology = arch_update_cpu_topology(); + /* Trigger rebuilding CPU capacity asymmetry data */ + if (new_topology) + asym_cpu_capacity_scan(); if (!doms_new) { WARN_ON_ONCE(dattr_new); diff --git a/kernel/signal.c b/kernel/signal.c index 30a0bee5ff9b..20d1d896d5b0 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -4679,7 +4679,7 @@ void kdb_send_sig(struct task_struct *t, int sig) } new_t = kdb_prev_t != t; kdb_prev_t = t; - if (t->state != TASK_RUNNING && new_t) { + if (!task_is_running(t) && new_t) { spin_unlock(&t->sighand->siglock); kdb_printf("Process is not RUNNING, sending a signal from " "kdb risks deadlock\n" diff --git a/kernel/smpboot.c b/kernel/smpboot.c index f25208e8df83..e4163042c4d6 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -33,7 +33,6 @@ struct task_struct *idle_thread_get(unsigned int cpu) if (!tsk) return ERR_PTR(-ENOMEM); - init_idle(tsk, cpu); return tsk; } diff --git a/kernel/softirq.c b/kernel/softirq.c index 4992853ef53d..f3a012179f47 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -76,7 +76,7 @@ static void wakeup_softirqd(void) /* Interrupts are disabled: no need to stop preemption */ struct task_struct *tsk = __this_cpu_read(ksoftirqd); - if (tsk && tsk->state != TASK_RUNNING) + if (tsk) wake_up_process(tsk); } @@ -92,8 +92,7 @@ static bool ksoftirqd_running(unsigned long pending) if (pending & SOFTIRQ_NOW_MASK) return false; - return tsk && (tsk->state == TASK_RUNNING) && - !__kthread_should_park(tsk); + return tsk && task_is_running(tsk) && !__kthread_should_park(tsk); } #ifdef CONFIG_TRACE_IRQFLAGS diff --git a/kernel/sys.c b/kernel/sys.c index 3a583a29815f..9de46a4bf492 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2550,6 +2550,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, error = set_syscall_user_dispatch(arg2, arg3, arg4, (char __user *) arg5); break; +#ifdef CONFIG_SCHED_CORE + case PR_SCHED_CORE: + error = sched_core_share_pid(arg2, arg3, arg4, arg5); + break; +#endif default: error = -EINVAL; break; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index d4a78e08f6d8..8c8c220637ce 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -71,6 +71,7 @@ #include <linux/coredump.h> #include <linux/latencytop.h> #include <linux/pid.h> +#include <linux/delayacct.h> #include "../lib/kstrtox.h" @@ -1747,6 +1748,17 @@ static struct ctl_table kern_table[] = { .extra2 = SYSCTL_ONE, }, #endif /* CONFIG_SCHEDSTATS */ +#ifdef CONFIG_TASK_DELAY_ACCT + { + .procname = "task_delayacct", + .data = NULL, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = sysctl_delayacct, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +#endif /* CONFIG_TASK_DELAY_ACCT */ #ifdef CONFIG_NUMA_BALANCING { .procname = "numa_balancing", diff --git a/kernel/time/timer.c b/kernel/time/timer.c index d111adf4a0cb..467087d7bdb6 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1879,7 +1879,7 @@ signed long __sched schedule_timeout(signed long timeout) printk(KERN_ERR "schedule_timeout: wrong timeout " "value %lx\n", timeout); dump_stack(); - current->state = TASK_RUNNING; + __set_current_state(TASK_RUNNING); goto out; } } diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c index 1c1dbd300325..046ac6297c78 100644 --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -19,11 +19,7 @@ unsigned int check_preemption_disabled(const char *what1, const char *what2) if (irqs_disabled()) goto out; - /* - * Kernel threads bound to a single CPU can safely use - * smp_processor_id(): - */ - if (current->nr_cpus_allowed == 1) + if (is_percpu_thread()) goto out; #ifdef CONFIG_SMP diff --git a/lib/syscall.c b/lib/syscall.c index ba13e924c430..006e256d2264 100644 --- a/lib/syscall.c +++ b/lib/syscall.c @@ -68,13 +68,13 @@ static int collect_syscall(struct task_struct *target, struct syscall_info *info */ int task_current_syscall(struct task_struct *target, struct syscall_info *info) { - long state; unsigned long ncsw; + unsigned int state; if (target == current) return collect_syscall(target, info); - state = target->state; + state = READ_ONCE(target->__state); if (unlikely(!state)) return -EAGAIN; diff --git a/mm/compaction.c b/mm/compaction.c index 84fde270ae74..725f564a5664 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1955,7 +1955,7 @@ static inline bool is_via_compact_memory(int order) static bool kswapd_is_running(pg_data_t *pgdat) { - return pgdat->kswapd && (pgdat->kswapd->state == TASK_RUNNING); + return pgdat->kswapd && task_is_running(pgdat->kswapd); } /* diff --git a/net/core/dev.c b/net/core/dev.c index ef8cf7619baf..2512f672bf8a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4363,7 +4363,7 @@ static inline void ____napi_schedule(struct softnet_data *sd, * makes sure to proceed with napi polling * if the thread is explicitly woken from here. */ - if (READ_ONCE(thread->state) != TASK_INTERRUPTIBLE) + if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE) set_bit(NAPI_STATE_SCHED_THREADED, &napi->state); wake_up_process(thread); return; diff --git a/tools/include/uapi/linux/prctl.h b/tools/include/uapi/linux/prctl.h index 18a9f59dc067..967d9c55323d 100644 --- a/tools/include/uapi/linux/prctl.h +++ b/tools/include/uapi/linux/prctl.h @@ -259,4 +259,12 @@ struct prctl_mm_map { #define PR_PAC_SET_ENABLED_KEYS 60 #define PR_PAC_GET_ENABLED_KEYS 61 +/* Request the scheduler to share a core */ +#define PR_SCHED_CORE 62 +# define PR_SCHED_CORE_GET 0 +# define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */ +# define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */ +# define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */ +# define PR_SCHED_CORE_MAX 4 + #endif /* _LINUX_PRCTL_H */ diff --git a/tools/testing/selftests/sched/.gitignore b/tools/testing/selftests/sched/.gitignore new file mode 100644 index 000000000000..6996d4654d92 --- /dev/null +++ b/tools/testing/selftests/sched/.gitignore @@ -0,0 +1 @@ +cs_prctl_test diff --git a/tools/testing/selftests/sched/Makefile b/tools/testing/selftests/sched/Makefile new file mode 100644 index 000000000000..10c72f14fea9 --- /dev/null +++ b/tools/testing/selftests/sched/Makefile @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0+ + +ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) +CLANG_FLAGS += -no-integrated-as +endif + +CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -Wl,-rpath=./ \ + $(CLANG_FLAGS) +LDLIBS += -lpthread + +TEST_GEN_FILES := cs_prctl_test +TEST_PROGS := cs_prctl_test + +include ../lib.mk diff --git a/tools/testing/selftests/sched/config b/tools/testing/selftests/sched/config new file mode 100644 index 000000000000..e8b09aa7c0c4 --- /dev/null +++ b/tools/testing/selftests/sched/config @@ -0,0 +1 @@ +CONFIG_SCHED_DEBUG=y diff --git a/tools/testing/selftests/sched/cs_prctl_test.c b/tools/testing/selftests/sched/cs_prctl_test.c new file mode 100644 index 000000000000..63fe6521c56d --- /dev/null +++ b/tools/testing/selftests/sched/cs_prctl_test.c @@ -0,0 +1,338 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Use the core scheduling prctl() to test core scheduling cookies control. + * + * Copyright (c) 2021 Oracle and/or its affiliates. + * Author: Chris Hyser <chris.hyser@oracle.com> + * + * + * This library is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License as + * published by the Free Software Foundation. + * + * This library is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License + * for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library; if not, see <http://www.gnu.org/licenses>. + */ + +#define _GNU_SOURCE +#include <sys/eventfd.h> +#include <sys/wait.h> +#include <sys/types.h> +#include <sched.h> +#include <sys/prctl.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> +#include <time.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#if __GLIBC_PREREQ(2, 30) == 0 +#include <sys/syscall.h> +static pid_t gettid(void) +{ + return syscall(SYS_gettid); +} +#endif + +#ifndef PR_SCHED_CORE +#define PR_SCHED_CORE 62 +# define PR_SCHED_CORE_GET 0 +# define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */ +# define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */ +# define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */ +# define PR_SCHED_CORE_MAX 4 +#endif + +#define MAX_PROCESSES 128 +#define MAX_THREADS 128 + +static const char USAGE[] = "cs_prctl_test [options]\n" +" options:\n" +" -P : number of processes to create.\n" +" -T : number of threads per process to create.\n" +" -d : delay time to keep tasks alive.\n" +" -k : keep tasks alive until keypress.\n"; + +enum pid_type {PIDTYPE_PID = 0, PIDTYPE_TGID, PIDTYPE_PGID}; + +const int THREAD_CLONE_FLAGS = CLONE_THREAD | CLONE_SIGHAND | CLONE_FS | CLONE_VM | CLONE_FILES; + +static int _prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, + unsigned long arg5) +{ + int res; + + res = prctl(option, arg2, arg3, arg4, arg5); + printf("%d = prctl(%d, %ld, %ld, %ld, %lx)\n", res, option, (long)arg2, (long)arg3, + (long)arg4, arg5); + return res; +} + +#define STACK_SIZE (1024 * 1024) + +#define handle_error(msg) __handle_error(__FILE__, __LINE__, msg) +static void __handle_error(char *fn, int ln, char *msg) +{ + printf("(%s:%d) - ", fn, ln); + perror(msg); + exit(EXIT_FAILURE); +} + +static void handle_usage(int rc, char *msg) +{ + puts(USAGE); + puts(msg); + putchar('\n'); + exit(rc); +} + +static unsigned long get_cs_cookie(int pid) +{ + unsigned long long cookie; + int ret; + + ret = prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, pid, PIDTYPE_PID, + (unsigned long)&cookie); + if (ret) { + printf("Not a core sched system\n"); + return -1UL; + } + + return cookie; +} + +struct child_args { + int num_threads; + int pfd[2]; + int cpid; + int thr_tids[MAX_THREADS]; +}; + +static int child_func_thread(void __attribute__((unused))*arg) +{ + while (1) + usleep(20000); + return 0; +} + +static void create_threads(int num_threads, int thr_tids[]) +{ + void *child_stack; + pid_t tid; + int i; + + for (i = 0; i < num_threads; ++i) { + child_stack = malloc(STACK_SIZE); + if (!child_stack) + handle_error("child stack allocate"); + + tid = clone(child_func_thread, child_stack + STACK_SIZE, THREAD_CLONE_FLAGS, NULL); + if (tid == -1) + handle_error("clone thread"); + thr_tids[i] = tid; + } +} + +static int child_func_process(void *arg) +{ + struct child_args *ca = (struct child_args *)arg; + + close(ca->pfd[0]); + + create_threads(ca->num_threads, ca->thr_tids); + + write(ca->pfd[1], &ca->thr_tids, sizeof(int) * ca->num_threads); + close(ca->pfd[1]); + + while (1) + usleep(20000); + return 0; +} + +static unsigned char child_func_process_stack[STACK_SIZE]; + +void create_processes(int num_processes, int num_threads, struct child_args proc[]) +{ + pid_t cpid; + int i; + + for (i = 0; i < num_processes; ++i) { + proc[i].num_threads = num_threads; + + if (pipe(proc[i].pfd) == -1) + handle_error("pipe() failed"); + + cpid = clone(child_func_process, child_func_process_stack + STACK_SIZE, + SIGCHLD, &proc[i]); + proc[i].cpid = cpid; + close(proc[i].pfd[1]); + } + + for (i = 0; i < num_processes; ++i) { + read(proc[i].pfd[0], &proc[i].thr_tids, sizeof(int) * proc[i].num_threads); + close(proc[i].pfd[0]); + } +} + +void disp_processes(int num_processes, struct child_args proc[]) +{ + int i, j; + + printf("tid=%d, / tgid=%d / pgid=%d: %lx\n", gettid(), getpid(), getpgid(0), + get_cs_cookie(getpid())); + + for (i = 0; i < num_processes; ++i) { + printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].cpid, proc[i].cpid, + getpgid(proc[i].cpid), get_cs_cookie(proc[i].cpid)); + for (j = 0; j < proc[i].num_threads; ++j) { + printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].thr_tids[j], + proc[i].cpid, getpgid(0), get_cs_cookie(proc[i].thr_tids[j])); + } + } + puts("\n"); +} + +static int errors; + +#define validate(v) _validate(__LINE__, v, #v) +void _validate(int line, int val, char *msg) +{ + if (!val) { + ++errors; + printf("(%d) FAILED: %s\n", line, msg); + } else { + printf("(%d) PASSED: %s\n", line, msg); + } +} + +int main(int argc, char *argv[]) +{ + struct child_args procs[MAX_PROCESSES]; + + int keypress = 0; + int num_processes = 2; + int num_threads = 3; + int delay = 0; + int res = 0; + int pidx; + int pid; + int opt; + + while ((opt = getopt(argc, argv, ":hkT:P:d:")) != -1) { + switch (opt) { + case 'P': + num_processes = (int)strtol(optarg, NULL, 10); + break; + case 'T': + num_threads = (int)strtoul(optarg, NULL, 10); + break; + case 'd': + delay = (int)strtol(optarg, NULL, 10); + break; + case 'k': + keypress = 1; + break; + case 'h': + printf(USAGE); + exit(EXIT_SUCCESS); + default: + handle_usage(20, "unknown option"); + } + } + + if (num_processes < 1 || num_processes > MAX_PROCESSES) + handle_usage(1, "Bad processes value"); + + if (num_threads < 1 || num_threads > MAX_THREADS) + handle_usage(2, "Bad thread value"); + + if (keypress) + delay = -1; + + srand(time(NULL)); + + /* put into separate process group */ + if (setpgid(0, 0) != 0) + handle_error("process group"); + + printf("\n## Create a thread/process/process group hiearchy\n"); + create_processes(num_processes, num_threads, procs); + disp_processes(num_processes, procs); + validate(get_cs_cookie(0) == 0); + + printf("\n## Set a cookie on entire process group\n"); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, 0, PIDTYPE_PGID, 0) < 0) + handle_error("core_sched create failed -- PGID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) != 0); + + /* get a random process pid */ + pidx = rand() % num_processes; + pid = procs[pidx].cpid; + + validate(get_cs_cookie(0) == get_cs_cookie(pid)); + validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Set a new cookie on entire process/TGID [%d]\n", pid); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, pid, PIDTYPE_TGID, 0) < 0) + handle_error("core_sched create failed -- TGID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) != get_cs_cookie(pid)); + validate(get_cs_cookie(pid) != 0); + validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Copy the cookie of current/PGID[%d], to pid [%d] as PIDTYPE_PID\n", + getpid(), pid); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, pid, PIDTYPE_PID, 0) < 0) + handle_error("core_sched share to itself failed -- PID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) == get_cs_cookie(pid)); + validate(get_cs_cookie(pid) != 0); + validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Copy cookie from a thread [%d] to current/PGID [%d] as PIDTYPE_PID\n", + procs[pidx].thr_tids[0], getpid()); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, procs[pidx].thr_tids[0], + PIDTYPE_PID, 0) < 0) + handle_error("core_sched share from thread failed -- PID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0])); + validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Copy cookie from current [%d] to current as pidtype PGID\n", getpid()); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, 0, PIDTYPE_PGID, 0) < 0) + handle_error("core_sched share to self failed -- PGID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) == get_cs_cookie(pid)); + validate(get_cs_cookie(pid) != 0); + validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0])); + + if (errors) { + printf("TESTS FAILED. errors: %d\n", errors); + res = 10; + } else { + printf("SUCCESS !!!\n"); + } + + if (keypress) + getchar(); + else + sleep(delay); + + for (pidx = 0; pidx < num_processes; ++pidx) + kill(procs[pidx].cpid, 15); + + return res; +} diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 46fb042837d2..b68678b52129 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -5040,7 +5040,7 @@ static void kvm_sched_out(struct preempt_notifier *pn, { struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); - if (current->state == TASK_RUNNING) { + if (current->on_rq) { WRITE_ONCE(vcpu->preempted, true); WRITE_ONCE(vcpu->ready, true); } |