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2016-09-30sched/irqtime: No need for preempt-safe accessorsFrederic Weisbecker1-2/+2
We can safely use the preempt-unsafe accessors for irqtime when we flush its counters to kcpustat as IRQs are disabled at this time. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/fair: Fix min_vruntime trackingPeter Zijlstra1-7/+22
While going through enqueue/dequeue to review the movement of set_curr_task() I noticed that the (2nd) update_min_vruntime() call in dequeue_entity() is suspect. It turns out, its actually wrong because it will consider cfs_rq->curr, which could be the entry we just normalized. This mixes different vruntime forms and leads to fail. The purpose of the second update_min_vruntime() is to move min_vruntime forward if the entity we just removed is the one that was holding it back; _except_ for the DEQUEUE_SAVE case, because then we know its a temporary removal and it will come back. However, since we do put_prev_task() _after_ dequeue(), cfs_rq->curr will still be set (and per the above, can be tranformed into a different unit), so update_min_vruntime() should also consider curr->on_rq. This also fixes another corner case where the enqueue (which also does update_curr()->update_min_vruntime()) happens on the rq->lock break in schedule(), between dequeue and put_prev_task. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: 1e876231785d ("sched: Fix ->min_vruntime calculation in dequeue_entity()") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/debug: Add SCHED_WARN_ON()Peter Zijlstra2-6/+10
Provide SCHED_WARN_ON as wrapper for WARN_ON_ONCE() to avoid CONFIG_SCHED_DEBUG wrappery. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Fix set_user_nice()Peter Zijlstra1-1/+7
Almost all scheduler functions update state with the following pattern: if (queued) dequeue_task(rq, p, DEQUEUE_SAVE); if (running) put_prev_task(rq, p); /* update state */ if (queued) enqueue_task(rq, p, ENQUEUE_RESTORE); if (running) set_curr_task(rq, p); set_user_nice() however misses the running part, cure this. This was found by asserting we never enqueue 'current'. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/fair: Introduce set_curr_task() helperPeter Zijlstra2-5/+10
Now that the ia64 only set_curr_task() symbol is gone, provide a helper just like put_prev_task(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core, ia64: Rename set_curr_task()Peter Zijlstra1-1/+1
Rename the ia64 only set_curr_task() function to free up the name. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Fix incorrect utilization accounting when switching to fair classVincent Guittot1-10/+10
When a task switches to fair scheduling class, the period between now and the last update of its utilization is accounted as running time whatever happened during this period. This incorrect accounting applies to the task and also to the task group branch. When changing the property of a running task like its list of allowed CPUs or its scheduling class, we follow the sequence: - dequeue task - put task - change the property - set task as current task - enqueue task The end of the sequence doesn't follow the normal sequence (as per __schedule()) which is: - enqueue a task - then set the task as current task. This incorrectordering is the root cause of incorrect utilization accounting. Update the sequence to follow the right one: - dequeue task - put task - change the property - enqueue task - set task as current task Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: linaro-kernel@lists.linaro.org Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1473666472-13749-8-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Optimize SCHED_SMTPeter Zijlstra3-7/+43
Avoid pointless SCHED_SMT code when running on !SMT hardware. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Rewrite and improve select_idle_siblings()Peter Zijlstra4-47/+231
select_idle_siblings() is a known pain point for a number of workloads; it either does too much or not enough and sometimes just does plain wrong. This rewrite attempts to address a number of issues (but sadly not all). The current code does an unconditional sched_domain iteration; with the intent of finding an idle core (on SMT hardware). The problems which this patch tries to address are: - its pointless to look for idle cores if the machine is real busy; at which point you're just wasting cycles. - it's behaviour is inconsistent between SMT and !SMT hardware in that !SMT hardware ends up doing a scan for any idle CPU in the LLC domain, while SMT hardware does a scan for idle cores and if that fails, falls back to a scan for idle threads on the 'target' core. The new code replaces the sched_domain scan with 3 explicit scans: 1) search for an idle core in the LLC 2) search for an idle CPU in the LLC 3) search for an idle thread in the 'target' core where 1 and 3 are conditional on SMT support and 1 and 2 have runtime heuristics to skip the step. Step 1) is conditional on sd_llc_shared->has_idle_cores; when a cpu goes idle and sd_llc_shared->has_idle_cores is false, we scan all SMT siblings of the CPU going idle. Similarly, we clear sd_llc_shared->has_idle_cores when we fail to find an idle core. Step 2) tracks the average cost of the scan and compares this to the average idle time guestimate for the CPU doing the wakeup. There is a significant fudge factor involved to deal with the variability of the averages. Esp. hackbench was sensitive to this. Step 3) is unconditional; we assume (also per step 1) that scanning all SMT siblings in a core is 'cheap'. With this; SMT systems gain step 2, which cures a few benchmarks -- notably one from Facebook. One 'feature' of the sched_domain iteration, which we preserve in the new code, is that it would start scanning from the 'target' CPU, instead of scanning the cpumask in cpu id order. This avoids multiple CPUs in the LLC scanning for idle to gang up and find the same CPU quite as much. The down side is that tasks can end up hopping across the LLC for no apparent reason. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Replace sd_busy/nr_busy_cpus with sched_domain_sharedPeter Zijlstra3-20/+18
Move the nr_busy_cpus thing from its hacky sd->parent->groups->sgc location into the much more natural sched_domain_shared location. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Introduce 'struct sched_domain_shared'Peter Zijlstra1-5/+39
Since struct sched_domain is strictly per cpu; introduce a structure that is shared between all 'identical' sched_domains. Limit to SD_SHARE_PKG_RESOURCES domains for now, as we'll only use it for shared cache state; if another use comes up later we can easily relax this. While the sched_group's are normally shared between CPUs, these are not natural to use when we need some shared state on a domain level -- since that would require the domain to have a parent, which is not a given. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Restructure destroy_sched_domain()Peter Zijlstra1-7/+11
There is no point in doing a call_rcu() for each domain, only do a callback for the root sched domain and clean up the entire set in one go. Also make the entire call chain be called destroy_sched_domain*() to remove confusion with the free_sched_domains() call, which does an entirely different thing. Both cpu_attach_domain() callers of destroy_sched_domain() can live without the call_rcu() because at those points the sched_domain hasn't been published yet. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Remove unused @cpu argument from destroy_sched_domain*()Peter Zijlstra1-6/+6
Small cleanup; nothing uses the @cpu argument so make it go away. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/wait: Introduce init_wait_entry()Oleg Nesterov1-3/+9
The partial initialization of wait_queue_t in prepare_to_wait_event() looks ugly. This was done to shrink .text, but we can simply add the new helper which does the full initialization and shrink the compiled code a bit more. And. This way prepare_to_wait_event() can have more users. In particular we are ready to remove the signal_pending_state() checks from wait_bit_action_f helpers and change __wait_on_bit_lock() to use prepare_to_wait_event(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160906140055.GA6167@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/wait: Avoid abort_exclusive_wait() in __wait_on_bit_lock()Oleg Nesterov1-43/+21
__wait_on_bit_lock() doesn't need abort_exclusive_wait() too. Right now it can't use prepare_to_wait_event() (see the next change), but it can do the additional finish_wait() if action() fails. abort_exclusive_wait() no longer has callers, remove it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160906140053.GA6164@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/wait: Avoid abort_exclusive_wait() in ___wait_event()Oleg Nesterov1-10/+25
___wait_event() doesn't really need abort_exclusive_wait(), we can simply change prepare_to_wait_event() to remove the waiter from q->task_list if it was interrupted. This simplifies the code/logic, and this way prepare_to_wait_event() can have more users, see the next change. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160908164815.GA18801@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> -- include/linux/wait.h | 7 +------ kernel/sched/wait.c | 35 +++++++++++++++++++++++++---------- 2 files changed, 26 insertions(+), 16 deletions(-)
2016-09-30sched/wait: Fix abort_exclusive_wait(), it should pass TASK_NORMAL to wake_up()Oleg Nesterov1-5/+3
Otherwise this logic only works if mode is "compatible" with another exclusive waiter. If some wq has both TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE waiters, abort_exclusive_wait() won't wait an uninterruptible waiter. The main user is __wait_on_bit_lock() and currently it is fine but only because TASK_KILLABLE includes TASK_UNINTERRUPTIBLE and we do not have lock_page_interruptible() yet. Just use TASK_NORMAL and remove the "mode" arg from abort_exclusive_wait(). Yes, this means that (say) wake_up_interruptible() can wake up the non- interruptible waiter(s), but I think this is fine. And in fact I think that abort_exclusive_wait() must die, see the next change. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160906140047.GA6157@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/fair: Fix fixed point arithmetic width for shares and effective loadDietmar Eggemann1-2/+2
Since commit: 2159197d6677 ("sched/core: Enable increased load resolution on 64-bit kernels") we now have two different fixed point units for load: - 'shares' in calc_cfs_shares() has 20 bit fixed point unit on 64-bit kernels. Therefore use scale_load() on MIN_SHARES. - 'wl' in effective_load() has 10 bit fixed point unit. Therefore use scale_load_down() on tg->shares which has 20 bit fixed point unit on 64-bit kernels. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471874441-24701-1-git-send-email-dietmar.eggemann@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core, x86/topology: Fix NUMA in package topology bugTim Chen1-0/+3
Current code can call set_cpu_sibling_map() and invoke sched_set_topology() more than once (e.g. on CPU hot plug). When this happens after sched_init_smp() has been called, we lose the NUMA topology extension to sched_domain_topology in sched_init_numa(). This results in incorrect topology when the sched domain is rebuilt. This patch fixes the bug and issues warning if we call sched_set_topology() after sched_init_smp(). Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/1474485552-141429-2-git-send-email-srinivas.pandruvada@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar5-24/+63
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-27Merge branch 'for-4.8-fixes' of ↵Linus Torvalds2-8/+40
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "Three late fixes for cgroup: Two cpuset ones, one trivial and the other pretty obscure, and a cgroup core fix for a bug which impacts cgroup v2 namespace users" * 'for-4.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix invalid controller enable rejections with cgroup namespace cpuset: fix non static symbol warning cpuset: handle race between CPU hotplug and cpuset_hotplug_work
2016-09-25Merge tag 'trace-v4.8-rc7' of ↵Linus Torvalds1-13/+16
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracefs fixes from Steven Rostedt: "Al Viro has been looking at the tracefs code, and has pointed out some issues. This contains one fix by me and one by Al. I'm sure that he'll come up with more but for now I tested these patches and they don't appear to have any negative impact on tracing" * tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: fix memory leaks in tracing_buffers_splice_read() tracing: Move mutex to protect against resetting of seq data
2016-09-25fix memory leaks in tracing_buffers_splice_read()Al Viro1-6/+8
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-25tracing: Move mutex to protect against resetting of seq dataSteven Rostedt (Red Hat)1-7/+8
The iter->seq can be reset outside the protection of the mutex. So can reading of user data. Move the mutex up to the beginning of the function. Fixes: d7350c3f45694 ("tracing/core: make the read callbacks reentrants") Cc: stable@vger.kernel.org # 2.6.30+ Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-09-24Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "Three fixlets for perf: - add a missing NULL pointer check in the intel BTS driver - make BTS an exclusive PMU because BTS can only handle one event at a time - ensure that exclusive events are limited to one PMU so that several exclusive events can be scheduled on different PMU instances" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Limit matching exclusive events to one PMU perf/x86/intel/bts: Make it an exclusive PMU perf/x86/intel/bts: Make sure debug store is valid
2016-09-24Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "Three fixes for irq core and irq chip drivers: - Do not set the irq type if type is NONE. Fixes a boot regression on various SoCs - Use the proper cpu for setting up the GIC target list. Discovered by the cpumask debugging code. - A rather large fix for the MIPS-GIC so per cpu local interrupts work again. This was discovered late because the code falls back to slower timers which use normal device interrupts" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/mips-gic: Fix local interrupts irqchip/gicv3: Silence noisy DEBUG_PER_CPU_MAPS warning genirq: Skip chained interrupt trigger setup if type is IRQ_TYPE_NONE
2016-09-23cgroup: fix invalid controller enable rejections with cgroup namespaceTejun Heo1-4/+25
On the v2 hierarchy, "cgroup.subtree_control" rejects controller enables if the cgroup has processes in it. The enforcement of this logic assumes that the cgroup wouldn't have any css_sets associated with it if there are no tasks in the cgroup, which is no longer true since a79a908fd2b0 ("cgroup: introduce cgroup namespaces"). When a cgroup namespace is created, it pins the css_set of the creating task to use it as the root css_set of the namespace. This extra reference stays as long as the namespace is around and makes "cgroup.subtree_control" think that the namespace root cgroup is not empty even when it is and thus reject controller enables. Fix it by making cgroup_subtree_control() walk and test emptiness of each css_set instead of testing whether the list_head is empty. While at it, update the comment of cgroup_task_count() to indicate that the returned value may be higher than the number of tasks, which has always been true due to temporary references and doesn't break anything. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Cc: Serge E. Hallyn <serge.hallyn@ubuntu.com> Cc: Aditya Kali <adityakali@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: stable@vger.kernel.org # v4.6+ Fixes: a79a908fd2b0 ("cgroup: introduce cgroup namespaces") Link: https://github.com/systemd/systemd/pull/3589#issuecomment-249089541
2016-09-22sched/debug: Hide printk() by defaultPeter Zijlstra1-1/+3
Dietmar accidentally added an unconditional sched domain printk. Hide it behind the normal sched_debug flag. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: cd92bfd3b8cb ("sched/core: Store maximum per-CPU capacity in root domain") [ Fixed !SCHED_DEBUG build failure. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/fair: Fix SCHED_HRTICK bug leading to late preemption of tasksSrivatsa Vaddagiri1-1/+1
SCHED_HRTICK feature is useful to preempt SCHED_FAIR tasks on-the-dot (just when they would have exceeded their ideal_runtime). It makes use of a per-CPU hrtimer resource and hence arming that hrtimer should be based on total SCHED_FAIR tasks a CPU has across its various cfs_rqs, rather than being based on number of tasks in a particular cfs_rq (as implemented currently). As a result, with current code, its possible for a running task (which is the sole task in its cfs_rq) to be preempted much after its ideal_runtime has elapsed, resulting in increased latency for tasks in other cfs_rq on same CPU. Fix this by arming sched hrtimer based on total number of SCHED_FAIR tasks a CPU has across its various cfs_rqs. Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org> Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1474075731-11550-1-git-send-email-joonwoop@codeaurora.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22perf/core: Limit matching exclusive events to one PMUAlexander Shishkin1-1/+1
An "exclusive" PMU is the one that can only have one event scheduled in at any given time. There may be more than one of such PMUs in a system, though, like Intel PT and BTS. It should be allowed to have one event for either of those inside the same context (there may be other constraints that may prevent this, but those would be hardware-specific). However, the exclusivity code is written so that only one event from any of the "exclusive" PMUs is allowed in a context. Fix this by making the exclusive event filter explicitly match two events' PMUs. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160920154811.3255-3-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Avoid _cond_resched() for PREEMPT=yPeter Zijlstra1-0/+2
On fully preemptible kernels _cond_resched() is pointless, so avoid emitting any code for it. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Optimize __schedule()Peter Zijlstra2-35/+29
Oleg noted that by making do_exit() use __schedule() for the TASK_DEAD context switch, we can avoid the TASK_DEAD special case currently in __schedule() because that avoids the extra preempt_disable() from schedule(). In order to facilitate this, create a do_task_dead() helper which we place in the scheduler code, such that it can access __schedule(). Also add some __noreturn annotations to the functions, there's no coming back from do_exit(). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Cheng Chao <cs.os.kernel@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: chris@chris-wilson.co.uk Cc: tj@kernel.org Link: http://lkml.kernel.org/r/20160913163729.GB5012@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22stop_machine: Avoid a sleep and wakeup in stop_one_cpu()Cheng Chao2-2/+11
In case @cpu == smp_proccessor_id(), we can avoid a sleep+wakeup cycle by doing a preemption. Callers such as sched_exec() can benefit from this change. Signed-off-by: Cheng Chao <cs.os.kernel@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: chris@chris-wilson.co.uk Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1473818510-6779-1-git-send-email-cs.os.kernel@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Remove unnecessary initialization in sched_init()Cheng Chao1-5/+0
init_idle() is called immediately after: current->sched_class = &fair_sched_class; init_idle() sets: current->sched_class = &idle_sched_class; First assignment is superfluous. Signed-off-by: Cheng Chao <cs.os.kernel@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1473819536-7398-1-git-send-email-cs.os.kernel@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar5-15/+73
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Do not use smp_processor_id() with preempt enabled in ↵Con Kolivas1-1/+1
smpboot_thread_fn() We should not be using smp_processor_id() with preempt enabled. Bug identified and fix provided by Alfred Chen. Reported-by: Alfred Chen <cchalpha@gmail.com> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: Alfred Chen <cchalpha@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/2042051.3vvUWIM0vs@hex Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-19cgroup: duplicate cgroup reference when cloning socketsJohannes Weiner1-0/+6
When a socket is cloned, the associated sock_cgroup_data is duplicated but not its reference on the cgroup. As a result, the cgroup reference count will underflow when both sockets are destroyed later on. Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Link: http://lkml.kernel.org/r/20160914194846.11153-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19genirq: Skip chained interrupt trigger setup if type is IRQ_TYPE_NONEMarc Zyngier1-2/+6
There is no point in trying to configure the trigger of a chained interrupt if no trigger information has been configured. At best this is ignored, and at the worse this confuses the underlying irqchip (which is likely not to handle such a thing), and unnecessarily alarms the user. Only apply the configuration if type is not IRQ_TYPE_NONE. Fixes: 1e12c4a9393b ("genirq: Correctly configure the trigger on chained interrupts") Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/CAMuHMdVW1eTn20=EtYcJ8hkVwohaSuH_yQXrY2MGBEvZ8fpFOg@mail.gmail.com Link: http://lkml.kernel.org/r/1474274967-15984-1-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-16cpuset: fix non static symbol warningWei Yongjun1-1/+1
Fixes the following sparse warning: kernel/cpuset.c:2088:6: warning: symbol 'cpuset_fork' was not declared. Should it be static? Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-09-13Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-0/+22
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "A try_to_wake_up() memory ordering race fix causing a busy-loop in ttwu()" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Fix a race between try_to_wake_up() and a woken up task
2016-09-13Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2-14/+48
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This contains: - a set of fixes found by directed-random perf fuzzing efforts by Vince Weaver, Alexander Shishkin and Peter Zijlstra - a cqm driver crash fix - an AMD uncore driver use after free fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Fix PEBSv3 record drain perf/x86/intel/bts: Kill a silly warning perf/x86/intel/bts: Fix BTS PMI detection perf/x86/intel/bts: Fix confused ordering of PMU callbacks perf/core: Fix aux_mmap_count vs aux_refcount order perf/core: Fix a race between mmap_close() and set_output() of AUX events perf/x86/amd/uncore: Prevent use after free perf/x86/intel/cqm: Check cqm/mbm enabled state in event init perf/core: Remove WARN from perf_event_read()
2016-09-13cpuset: handle race between CPU hotplug and cpuset_hotplug_workJoonwoo Park1-3/+14
A discrepancy between cpu_online_mask and cpuset's effective_cpus mask is inevitable during hotplug since cpuset defers updating of effective_cpus mask using a workqueue, during which time nothing prevents the system from more hotplug operations. For that reason guarantee_online_cpus() walks up the cpuset hierarchy until it finds an intersection under the assumption that top cpuset's effective_cpus mask intersects with cpu_online_mask even with such a race occurring. However a sequence of CPU hotplugs can open a time window, during which none of the effective CPUs in the top cpuset intersect with cpu_online_mask. For example when there are 4 possible CPUs 0-3 and only CPU0 is online: ======================== =========================== cpu_online_mask top_cpuset.effective_cpus ======================== =========================== echo 1 > cpu2/online. CPU hotplug notifier woke up hotplug work but not yet scheduled. [0,2] [0] echo 0 > cpu0/online. The workqueue is still runnable. [2] [0] ======================== =========================== Now there is no intersection between cpu_online_mask and top_cpuset.effective_cpus. Thus invoking sys_sched_setaffinity() at this moment can cause following: Unable to handle kernel NULL pointer dereference at virtual address 000000d0 ------------[ cut here ]------------ Kernel BUG at ffffffc0001389b0 [verbose debug info unavailable] Internal error: Oops - BUG: 96000005 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 1420 Comm: taskset Tainted: G W 4.4.8+ #98 task: ffffffc06a5c4880 ti: ffffffc06e124000 task.ti: ffffffc06e124000 PC is at guarantee_online_cpus+0x2c/0x58 LR is at cpuset_cpus_allowed+0x4c/0x6c <snip> Process taskset (pid: 1420, stack limit = 0xffffffc06e124020) Call trace: [<ffffffc0001389b0>] guarantee_online_cpus+0x2c/0x58 [<ffffffc00013b208>] cpuset_cpus_allowed+0x4c/0x6c [<ffffffc0000d61f0>] sched_setaffinity+0xc0/0x1ac [<ffffffc0000d6374>] SyS_sched_setaffinity+0x98/0xac [<ffffffc000085cb0>] el0_svc_naked+0x24/0x28 The top cpuset's effective_cpus are guaranteed to be identical to cpu_online_mask eventually. Hence fall back to cpu_online_mask when there is no intersection between top cpuset's effective_cpus and cpu_online_mask. Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Tejun Heo <tj@kernel.org> Cc: cgroups@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> # 3.17+ Signed-off-by: Tejun Heo <tj@kernel.org>
2016-09-10Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds1-0/+9
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "nvdimm fixes for v4.8, two of them are tagged for -stable: - Fix devm_memremap_pages() to use track_pfn_insert(). Otherwise, DAX pmd mappings end up with an uncached pgprot, and unusable performance for the device-dax interface. The device-dax interface appeared in 4.7 so this is tagged for -stable. - Fix a couple VM_BUG_ON() checks in the show_smaps() path to understand DAX pmd entries. This fix is tagged for -stable. - Fix a mis-merge of the nfit machine-check handler to flip the polarity of an if() to match the final version of the patch that Vishal sent for 4.8-rc1. Without this the nfit machine check handler never detects / inserts new 'badblocks' entries which applications use to identify lost portions of files. - For test purposes, fix the nvdimm_clear_poison() path to operate on legacy / simulated nvdimm memory ranges. Without this fix a test can set badblocks, but never clear them on these ranges. - Fix the range checking done by dax_dev_pmd_fault(). This is not tagged for -stable since this problem is mitigated by specifying aligned resources at device-dax setup time. These patches have appeared in a next release over the past week. The recent rebase you can see in the timestamps was to drop an invalid fix as identified by the updated device-dax unit tests [1]. The -mm touches have an ack from Andrew" [1]: "[ndctl PATCH 0/3] device-dax test for recent kernel bugs" https://lists.01.org/pipermail/linux-nvdimm/2016-September/006855.html * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm: allow legacy (e820) pmem region to clear bad blocks nfit, mce: Fix SPA matching logic in MCE handler mm: fix cache mode of dax pmd mappings mm: fix show_smap() for zone_device-pmd ranges dax: fix mapping size check
2016-09-10Revert "sched/fair: Make update_min_vruntime() more readable"Peter Zijlstra1-4/+7
There's a bug in this commit: 97a7142f157a ("sched/fair: Make update_min_vruntime() more readable") ... when !rb_leftmost && curr we fail to advance min_vruntime. So revert it. Reported-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-10perf/core: Fix aux_mmap_count vs aux_refcount orderAlexander Shishkin1-4/+11
The order of accesses to ring buffer's aux_mmap_count and aux_refcount has to be preserved across the users, namely perf_mmap_close() and perf_aux_output_begin(), otherwise the inversion can result in the latter holding the last reference to the aux buffer and subsequently free'ing it in atomic context, triggering a warning. > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 257 at kernel/events/ring_buffer.c:541 __rb_free_aux+0x11a/0x130 > CPU: 0 PID: 257 Comm: stopbug Not tainted 4.8.0-rc1+ #2596 > Call Trace: > [<ffffffff810f3e0b>] __warn+0xcb/0xf0 > [<ffffffff810f3f3d>] warn_slowpath_null+0x1d/0x20 > [<ffffffff8121182a>] __rb_free_aux+0x11a/0x130 > [<ffffffff812127a8>] rb_free_aux+0x18/0x20 > [<ffffffff81212913>] perf_aux_output_begin+0x163/0x1e0 > [<ffffffff8100c33a>] bts_event_start+0x3a/0xd0 > [<ffffffff8100c42d>] bts_event_add+0x5d/0x80 > [<ffffffff81203646>] event_sched_in.isra.104+0xf6/0x2f0 > [<ffffffff8120652e>] group_sched_in+0x6e/0x190 > [<ffffffff8120694e>] ctx_sched_in+0x2fe/0x5f0 > [<ffffffff81206ca0>] perf_event_sched_in+0x60/0x80 > [<ffffffff81206d1b>] ctx_resched+0x5b/0x90 > [<ffffffff81207281>] __perf_event_enable+0x1e1/0x240 > [<ffffffff81200639>] event_function+0xa9/0x180 > [<ffffffff81202000>] ? perf_cgroup_attach+0x70/0x70 > [<ffffffff8120203f>] remote_function+0x3f/0x50 > [<ffffffff811971f3>] flush_smp_call_function_queue+0x83/0x150 > [<ffffffff81197bd3>] generic_smp_call_function_single_interrupt+0x13/0x60 > [<ffffffff810a6477>] smp_call_function_single_interrupt+0x27/0x40 > [<ffffffff81a26ea9>] call_function_single_interrupt+0x89/0x90 > [<ffffffff81120056>] finish_task_switch+0xa6/0x210 > [<ffffffff81120017>] ? finish_task_switch+0x67/0x210 > [<ffffffff81a1e83d>] __schedule+0x3dd/0xb50 > [<ffffffff81a1efe5>] schedule+0x35/0x80 > [<ffffffff81128031>] sys_sched_yield+0x61/0x70 > [<ffffffff81a25be5>] entry_SYSCALL_64_fastpath+0x18/0xa8 > ---[ end trace 6235f556f5ea83a9 ]--- This patch puts the checks in perf_aux_output_begin() in the same order as that of perf_mmap_close(). Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160906132353.19887-3-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-10perf/core: Fix a race between mmap_close() and set_output() of AUX eventsAlexander Shishkin1-6/+25
In the mmap_close() path we need to stop all the AUX events that are writing data to the AUX area that we are unmapping, before we can safely free the pages. To determine if an event needs to be stopped, we're comparing its ->rb against the one that's getting unmapped. However, a SET_OUTPUT ioctl may turn up inside an AUX transaction and swizzle event::rb to some other ring buffer, but the transaction will keep writing data to the old ring buffer until the event gets scheduled out. At this point, mmap_close() will skip over such an event and will proceed to free the AUX area, while it's still being used by this event, which will set off a warning in the mmap_close() path and cause a memory corruption. To avoid this, always stop an AUX event before its ->rb is updated; this will release the (potentially) last reference on the AUX area of the buffer. If the event gets restarted, its new ring buffer will be used. If another SET_OUTPUT comes and switches it back to the old ring buffer that's getting unmapped, it's also fine: this ring buffer's aux_mmap_count will be zero and AUX transactions won't start any more. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160906132353.19887-2-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-09mm: fix cache mode of dax pmd mappingsDan Williams1-0/+9
track_pfn_insert() in vmf_insert_pfn_pmd() is marking dax mappings as uncacheable rendering them impractical for application usage. DAX-pte mappings are cached and the goal of establishing DAX-pmd mappings is to attain more performance, not dramatically less (3 orders of magnitude). track_pfn_insert() relies on a previous call to reserve_memtype() to establish the expected page_cache_mode for the range. While memremap() arranges for reserve_memtype() to be called, devm_memremap_pages() does not. So, teach track_pfn_insert() and untrack_pfn() how to handle tracking without a vma, and arrange for devm_memremap_pages() to establish the write-back-cache reservation in the memtype tree. Cc: <stable@vger.kernel.org> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Toshi Kani <toshi.kani@hpe.com> Reported-by: Kai Zhang <kai.ka.zhang@oracle.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-09-05PM / QoS: avoid calling cancel_delayed_work_sync() during early bootTejun Heo1-1/+10
of_clk_init() ends up calling into pm_qos_update_request() very early during boot where irq is expected to stay disabled. pm_qos_update_request() uses cancel_delayed_work_sync() which correctly assumes that irq is enabled on invocation and unconditionally disables and re-enables it. Gate cancel_delayed_work_sync() invocation with kevented_up() to avoid enabling irq unexpectedly during early boot. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Qiao Zhou <qiaozhou@asrmicro.com> Link: http://lkml.kernel.org/r/d2501c4c-8e7b-bea3-1b01-000b36b5dfe9@asrmicro.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-05sched/debug: Remove several CONFIG_SCHEDSTATS guardsJosh Poimboeuf3-144/+136
Clean up the sched code by removing several of the CONFIG_SCHEDSTATS guards, using schedstat_*() macros where needed. Code size: !CONFIG_SCHEDSTATS defconfig: text data bss dec hex filename 10209818 4368184 1105920 15683922 ef5152 vmlinux.before.nostats 10209818 4368184 1105920 15683922 ef5152 vmlinux.after.nostats CONFIG_SCHEDSTATS defconfig: text data bss dec hex filename 10214210 4370040 1105920 15690170 ef69ba vmlinux.before.stats 10214210 4370680 1105920 15690810 ef6c3a vmlinux.after.stats Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e51e0ebe5af95ac295de720dd252e7c0d2142e4a.1466184592.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-05sched/debug: Rename 'schedstat_val()' -> 'schedstat_val_or_zero()'Josh Poimboeuf2-3/+5
The schedstat_val() macro's behavior is kind of surprising: when schedstat is runtime disabled, it returns zero. Rename it to schedstat_val_or_zero(). There's also a need for a similar macro which doesn't have the 'if (schedstat_enable())' check, to avoid doing the check twice. Create a new 'schedstat_val()' macro for that. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/3bb1d2367d041fee333b0dde17171e709395b675.1466184592.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>