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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-30 17:01:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-30 17:01:51 -0700
commit642e53ead6aea8740a219ede509a5d138fd4f780 (patch)
tree5c4680d0c07315dab24fe7333c62f56bc19ec4e4 /kernel
parent9b82f05f869a823d43ea4186f5f732f2924d3693 (diff)
parent313f16e2e35abb833eab5bdebc6ae30699adca18 (diff)
downloadlinux-642e53ead6aea8740a219ede509a5d138fd4f780.tar.bz2
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: "The main changes in this cycle are: - Various NUMA scheduling updates: harmonize the load-balancer and NUMA placement logic to not work against each other. The intended result is better locality, better utilization and fewer migrations. - Introduce Thermal Pressure tracking and optimizations, to improve task placement on thermally overloaded systems. - Implement frequency invariant scheduler accounting on (some) x86 CPUs. This is done by observing and sampling the 'recent' CPU frequency average at ~tick boundaries. The CPU provides this data via the APERF/MPERF MSRs. This hopefully makes our capacity estimates more precise and keeps tasks on the same CPU better even if it might seem overloaded at a lower momentary frequency. (As usual, turbo mode is a complication that we resolve by observing the maximum frequency and renormalizing to it.) - Add asymmetric CPU capacity wakeup scan to improve capacity utilization on asymmetric topologies. (big.LITTLE systems) - PSI fixes and optimizations. - RT scheduling capacity awareness fixes & improvements. - Optimize the CONFIG_RT_GROUP_SCHED constraints code. - Misc fixes, cleanups and optimizations - see the changelog for details" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (62 commits) threads: Update PID limit comment according to futex UAPI change sched/fair: Fix condition of avg_load calculation sched/rt: cpupri_find: Trigger a full search as fallback kthread: Do not preempt current task if it is going to call schedule() sched/fair: Improve spreading of utilization sched: Avoid scale real weight down to zero psi: Move PF_MEMSTALL out of task->flags MAINTAINERS: Add maintenance information for psi psi: Optimize switching tasks inside shared cgroups psi: Fix cpu.pressure for cpu.max and competing cgroups sched/core: Distribute tasks within affinity masks sched/fair: Fix enqueue_task_fair warning thermal/cpu-cooling, sched/core: Move the arch_set_thermal_pressure() API to generic scheduler code sched/rt: Remove unnecessary push for unfit tasks sched/rt: Allow pulling unfitting task sched/rt: Optimize cpupri_find() on non-heterogenous systems sched/rt: Re-instate old behavior in select_task_rq_rt() sched/rt: cpupri_find: Implement fallback mechanism for !fit case sched/fair: Fix reordering of enqueue/dequeue_task_fair() sched/fair: Fix runnable_avg for throttled cfs ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kthread.c17
-rw-r--r--kernel/sched/core.c27
-rw-r--r--kernel/sched/cpupri.c158
-rw-r--r--kernel/sched/cpupri.h6
-rw-r--r--kernel/sched/cputime.c41
-rw-r--r--kernel/sched/deadline.c6
-rw-r--r--kernel/sched/debug.c17
-rw-r--r--kernel/sched/fair.c791
-rw-r--r--kernel/sched/pelt.c90
-rw-r--r--kernel/sched/pelt.h31
-rw-r--r--kernel/sched/psi.c111
-rw-r--r--kernel/sched/rt.c66
-rw-r--r--kernel/sched/sched.h69
-rw-r--r--kernel/sched/stats.h31
-rw-r--r--kernel/sched/topology.c27
15 files changed, 1026 insertions, 462 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c
index b262f47046ca..bfbfa481be3a 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -199,8 +199,15 @@ static void __kthread_parkme(struct kthread *self)
if (!test_bit(KTHREAD_SHOULD_PARK, &self->flags))
break;
+ /*
+ * Thread is going to call schedule(), do not preempt it,
+ * or the caller of kthread_park() may spend more time in
+ * wait_task_inactive().
+ */
+ preempt_disable();
complete(&self->parked);
- schedule();
+ schedule_preempt_disabled();
+ preempt_enable();
}
__set_current_state(TASK_RUNNING);
}
@@ -245,8 +252,14 @@ static int kthread(void *_create)
/* OK, tell user we're spawned, wait for stop or wakeup */
__set_current_state(TASK_UNINTERRUPTIBLE);
create->result = current;
+ /*
+ * Thread is going to call schedule(), do not preempt it,
+ * or the creator may spend more time in wait_task_inactive().
+ */
+ preempt_disable();
complete(done);
- schedule();
+ schedule_preempt_disabled();
+ preempt_enable();
ret = -EINTR;
if (!test_bit(KTHREAD_SHOULD_STOP, &self->flags)) {
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 1a9983da4408..c1f923d647ee 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -761,7 +761,6 @@ static void set_load_weight(struct task_struct *p, bool update_load)
if (task_has_idle_policy(p)) {
load->weight = scale_load(WEIGHT_IDLEPRIO);
load->inv_weight = WMULT_IDLEPRIO;
- p->se.runnable_weight = load->weight;
return;
}
@@ -774,7 +773,6 @@ static void set_load_weight(struct task_struct *p, bool update_load)
} else {
load->weight = scale_load(sched_prio_to_weight[prio]);
load->inv_weight = sched_prio_to_wmult[prio];
- p->se.runnable_weight = load->weight;
}
}
@@ -1652,7 +1650,12 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
if (cpumask_equal(p->cpus_ptr, new_mask))
goto out;
- dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);
+ /*
+ * Picking a ~random cpu helps in cases where we are changing affinity
+ * for groups of tasks (ie. cpuset), so that load balancing is not
+ * immediately required to distribute the tasks within their new mask.
+ */
+ dest_cpu = cpumask_any_and_distribute(cpu_valid_mask, new_mask);
if (dest_cpu >= nr_cpu_ids) {
ret = -EINVAL;
goto out;
@@ -3578,6 +3581,17 @@ unsigned long long task_sched_runtime(struct task_struct *p)
return ns;
}
+DEFINE_PER_CPU(unsigned long, thermal_pressure);
+
+void arch_set_thermal_pressure(struct cpumask *cpus,
+ unsigned long th_pressure)
+{
+ int cpu;
+
+ for_each_cpu(cpu, cpus)
+ WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);
+}
+
/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
@@ -3588,12 +3602,16 @@ void scheduler_tick(void)
struct rq *rq = cpu_rq(cpu);
struct task_struct *curr = rq->curr;
struct rq_flags rf;
+ unsigned long thermal_pressure;
+ arch_scale_freq_tick();
sched_clock_tick();
rq_lock(rq, &rf);
update_rq_clock(rq);
+ thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
+ update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure);
curr->sched_class->task_tick(rq, curr, 0);
calc_global_load_tick(rq);
psi_task_tick(rq);
@@ -3671,7 +3689,6 @@ static void sched_tick_remote(struct work_struct *work)
if (cpu_is_offline(cpu))
goto out_unlock;
- curr = rq->curr;
update_rq_clock(rq);
if (!is_idle_task(curr)) {
@@ -4074,6 +4091,8 @@ static void __sched notrace __schedule(bool preempt)
*/
++*switch_count;
+ psi_sched_switch(prev, next, !task_on_rq_queued(prev));
+
trace_sched_switch(preempt, prev, next);
/* Also unlocks the rq: */
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index 1a2719e1350a..0033731a0797 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -41,8 +41,67 @@ static int convert_prio(int prio)
return cpupri;
}
+static inline int __cpupri_find(struct cpupri *cp, struct task_struct *p,
+ struct cpumask *lowest_mask, int idx)
+{
+ struct cpupri_vec *vec = &cp->pri_to_cpu[idx];
+ int skip = 0;
+
+ if (!atomic_read(&(vec)->count))
+ skip = 1;
+ /*
+ * When looking at the vector, we need to read the counter,
+ * do a memory barrier, then read the mask.
+ *
+ * Note: This is still all racey, but we can deal with it.
+ * Ideally, we only want to look at masks that are set.
+ *
+ * If a mask is not set, then the only thing wrong is that we
+ * did a little more work than necessary.
+ *
+ * If we read a zero count but the mask is set, because of the
+ * memory barriers, that can only happen when the highest prio
+ * task for a run queue has left the run queue, in which case,
+ * it will be followed by a pull. If the task we are processing
+ * fails to find a proper place to go, that pull request will
+ * pull this task if the run queue is running at a lower
+ * priority.
+ */
+ smp_rmb();
+
+ /* Need to do the rmb for every iteration */
+ if (skip)
+ return 0;
+
+ if (cpumask_any_and(p->cpus_ptr, vec->mask) >= nr_cpu_ids)
+ return 0;
+
+ if (lowest_mask) {
+ cpumask_and(lowest_mask, p->cpus_ptr, vec->mask);
+
+ /*
+ * We have to ensure that we have at least one bit
+ * still set in the array, since the map could have
+ * been concurrently emptied between the first and
+ * second reads of vec->mask. If we hit this
+ * condition, simply act as though we never hit this
+ * priority level and continue on.
+ */
+ if (cpumask_empty(lowest_mask))
+ return 0;
+ }
+
+ return 1;
+}
+
+int cpupri_find(struct cpupri *cp, struct task_struct *p,
+ struct cpumask *lowest_mask)
+{
+ return cpupri_find_fitness(cp, p, lowest_mask, NULL);
+}
+
/**
- * cpupri_find - find the best (lowest-pri) CPU in the system
+ * cpupri_find_fitness - find the best (lowest-pri) CPU in the system
* @cp: The cpupri context
* @p: The task
* @lowest_mask: A mask to fill in with selected CPUs (or NULL)
@@ -58,84 +117,59 @@ static int convert_prio(int prio)
*
* Return: (int)bool - CPUs were found
*/
-int cpupri_find(struct cpupri *cp, struct task_struct *p,
+int cpupri_find_fitness(struct cpupri *cp, struct task_struct *p,
struct cpumask *lowest_mask,
bool (*fitness_fn)(struct task_struct *p, int cpu))
{
- int idx = 0;
int task_pri = convert_prio(p->prio);
+ int idx, cpu;
BUG_ON(task_pri >= CPUPRI_NR_PRIORITIES);
for (idx = 0; idx < task_pri; idx++) {
- struct cpupri_vec *vec = &cp->pri_to_cpu[idx];
- int skip = 0;
-
- if (!atomic_read(&(vec)->count))
- skip = 1;
- /*
- * When looking at the vector, we need to read the counter,
- * do a memory barrier, then read the mask.
- *
- * Note: This is still all racey, but we can deal with it.
- * Ideally, we only want to look at masks that are set.
- *
- * If a mask is not set, then the only thing wrong is that we
- * did a little more work than necessary.
- *
- * If we read a zero count but the mask is set, because of the
- * memory barriers, that can only happen when the highest prio
- * task for a run queue has left the run queue, in which case,
- * it will be followed by a pull. If the task we are processing
- * fails to find a proper place to go, that pull request will
- * pull this task if the run queue is running at a lower
- * priority.
- */
- smp_rmb();
- /* Need to do the rmb for every iteration */
- if (skip)
+ if (!__cpupri_find(cp, p, lowest_mask, idx))
continue;
- if (cpumask_any_and(p->cpus_ptr, vec->mask) >= nr_cpu_ids)
- continue;
+ if (!lowest_mask || !fitness_fn)
+ return 1;
- if (lowest_mask) {
- int cpu;
-
- cpumask_and(lowest_mask, p->cpus_ptr, vec->mask);
-
- /*
- * We have to ensure that we have at least one bit
- * still set in the array, since the map could have
- * been concurrently emptied between the first and
- * second reads of vec->mask. If we hit this
- * condition, simply act as though we never hit this
- * priority level and continue on.
- */
- if (cpumask_empty(lowest_mask))
- continue;
-
- if (!fitness_fn)
- return 1;
-
- /* Ensure the capacity of the CPUs fit the task */
- for_each_cpu(cpu, lowest_mask) {
- if (!fitness_fn(p, cpu))
- cpumask_clear_cpu(cpu, lowest_mask);
- }
-
- /*
- * If no CPU at the current priority can fit the task
- * continue looking
- */
- if (cpumask_empty(lowest_mask))
- continue;
+ /* Ensure the capacity of the CPUs fit the task */
+ for_each_cpu(cpu, lowest_mask) {
+ if (!fitness_fn(p, cpu))
+ cpumask_clear_cpu(cpu, lowest_mask);
}
+ /*
+ * If no CPU at the current priority can fit the task
+ * continue looking
+ */
+ if (cpumask_empty(lowest_mask))
+ continue;
+
return 1;
}
+ /*
+ * If we failed to find a fitting lowest_mask, kick off a new search
+ * but without taking into account any fitness criteria this time.
+ *
+ * This rule favours honouring priority over fitting the task in the
+ * correct CPU (Capacity Awareness being the only user now).
+ * The idea is that if a higher priority task can run, then it should
+ * run even if this ends up being on unfitting CPU.
+ *
+ * The cost of this trade-off is not entirely clear and will probably
+ * be good for some workloads and bad for others.
+ *
+ * The main idea here is that if some CPUs were overcommitted, we try
+ * to spread which is what the scheduler traditionally did. Sys admins
+ * must do proper RT planning to avoid overloading the system if they
+ * really care.
+ */
+ if (fitness_fn)
+ return cpupri_find(cp, p, lowest_mask);
+
return 0;
}
diff --git a/kernel/sched/cpupri.h b/kernel/sched/cpupri.h
index 32dd520db11f..efbb492bb94c 100644
--- a/kernel/sched/cpupri.h
+++ b/kernel/sched/cpupri.h
@@ -19,8 +19,10 @@ struct cpupri {
#ifdef CONFIG_SMP
int cpupri_find(struct cpupri *cp, struct task_struct *p,
- struct cpumask *lowest_mask,
- bool (*fitness_fn)(struct task_struct *p, int cpu));
+ struct cpumask *lowest_mask);
+int cpupri_find_fitness(struct cpupri *cp, struct task_struct *p,
+ struct cpumask *lowest_mask,
+ bool (*fitness_fn)(struct task_struct *p, int cpu));
void cpupri_set(struct cpupri *cp, int cpu, int pri);
int cpupri_init(struct cpupri *cp);
void cpupri_cleanup(struct cpupri *cp);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index cff3e656566d..dac9104d126f 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -909,8 +909,10 @@ void task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
} while (read_seqcount_retry(&vtime->seqcount, seq));
}
-static int vtime_state_check(struct vtime *vtime, int cpu)
+static int vtime_state_fetch(struct vtime *vtime, int cpu)
{
+ int state = READ_ONCE(vtime->state);
+
/*
* We raced against a context switch, fetch the
* kcpustat task again.
@@ -927,10 +929,10 @@ static int vtime_state_check(struct vtime *vtime, int cpu)
*
* Case 1) is ok but 2) is not. So wait for a safe VTIME state.
*/
- if (vtime->state == VTIME_INACTIVE)
+ if (state == VTIME_INACTIVE)
return -EAGAIN;
- return 0;
+ return state;
}
static u64 kcpustat_user_vtime(struct vtime *vtime)
@@ -949,14 +951,15 @@ static int kcpustat_field_vtime(u64 *cpustat,
{
struct vtime *vtime = &tsk->vtime;
unsigned int seq;
- int err;
do {
+ int state;
+
seq = read_seqcount_begin(&vtime->seqcount);
- err = vtime_state_check(vtime, cpu);
- if (err < 0)
- return err;
+ state = vtime_state_fetch(vtime, cpu);
+ if (state < 0)
+ return state;
*val = cpustat[usage];
@@ -969,7 +972,7 @@ static int kcpustat_field_vtime(u64 *cpustat,
*/
switch (usage) {
case CPUTIME_SYSTEM:
- if (vtime->state == VTIME_SYS)
+ if (state == VTIME_SYS)
*val += vtime->stime + vtime_delta(vtime);
break;
case CPUTIME_USER:
@@ -981,11 +984,11 @@ static int kcpustat_field_vtime(u64 *cpustat,
*val += kcpustat_user_vtime(vtime);
break;
case CPUTIME_GUEST:
- if (vtime->state == VTIME_GUEST && task_nice(tsk) <= 0)
+ if (state == VTIME_GUEST && task_nice(tsk) <= 0)
*val += vtime->gtime + vtime_delta(vtime);
break;
case CPUTIME_GUEST_NICE:
- if (vtime->state == VTIME_GUEST && task_nice(tsk) > 0)
+ if (state == VTIME_GUEST && task_nice(tsk) > 0)
*val += vtime->gtime + vtime_delta(vtime);
break;
default:
@@ -1036,23 +1039,23 @@ static int kcpustat_cpu_fetch_vtime(struct kernel_cpustat *dst,
{
struct vtime *vtime = &tsk->vtime;
unsigned int seq;
- int err;
do {
u64 *cpustat;
u64 delta;
+ int state;
seq = read_seqcount_begin(&vtime->seqcount);
- err = vtime_state_check(vtime, cpu);
- if (err < 0)
- return err;
+ state = vtime_state_fetch(vtime, cpu);
+ if (state < 0)
+ return state;
*dst = *src;
cpustat = dst->cpustat;
/* Task is sleeping, dead or idle, nothing to add */
- if (vtime->state < VTIME_SYS)
+ if (state < VTIME_SYS)
continue;
delta = vtime_delta(vtime);
@@ -1061,15 +1064,15 @@ static int kcpustat_cpu_fetch_vtime(struct kernel_cpustat *dst,
* Task runs either in user (including guest) or kernel space,
* add pending nohz time to the right place.
*/
- if (vtime->state == VTIME_SYS) {
+ if (state == VTIME_SYS) {
cpustat[CPUTIME_SYSTEM] += vtime->stime + delta;
- } else if (vtime->state == VTIME_USER) {
+ } else if (state == VTIME_USER) {
if (task_nice(tsk) > 0)
cpustat[CPUTIME_NICE] += vtime->utime + delta;
else
cpustat[CPUTIME_USER] += vtime->utime + delta;
} else {
- WARN_ON_ONCE(vtime->state != VTIME_GUEST);
+ WARN_ON_ONCE(state != VTIME_GUEST);
if (task_nice(tsk) > 0) {
cpustat[CPUTIME_GUEST_NICE] += vtime->gtime + delta;
cpustat[CPUTIME_NICE] += vtime->gtime + delta;
@@ -1080,7 +1083,7 @@ static int kcpustat_cpu_fetch_vtime(struct kernel_cpustat *dst,
}
} while (read_seqcount_retry(&vtime->seqcount, seq));
- return err;
+ return 0;
}
void kcpustat_cpu_fetch(struct kernel_cpustat *dst, int cpu)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 43323f875cb9..504d2f51b0d6 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -153,7 +153,7 @@ void sub_running_bw(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
__sub_running_bw(dl_se->dl_bw, dl_rq);
}
-void dl_change_utilization(struct task_struct *p, u64 new_bw)
+static void dl_change_utilization(struct task_struct *p, u64 new_bw)
{
struct rq *rq;
@@ -334,6 +334,8 @@ static inline int is_leftmost(struct task_struct *p, struct dl_rq *dl_rq)
return dl_rq->root.rb_leftmost == &dl_se->rb_node;
}
+static void init_dl_rq_bw_ratio(struct dl_rq *dl_rq);
+
void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime)
{
raw_spin_lock_init(&dl_b->dl_runtime_lock);
@@ -2496,7 +2498,7 @@ int sched_dl_global_validate(void)
return ret;
}
-void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)
+static void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)
{
if (global_rt_runtime() == RUNTIME_INF) {
dl_rq->bw_ratio = 1 << RATIO_SHIFT;
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 879d3ccf3806..8331bc04aea2 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -402,11 +402,10 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
}
P(se->load.weight);
- P(se->runnable_weight);
#ifdef CONFIG_SMP
P(se->avg.load_avg);
P(se->avg.util_avg);
- P(se->avg.runnable_load_avg);
+ P(se->avg.runnable_avg);
#endif
#undef PN_SCHEDSTAT
@@ -524,11 +523,10 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SEQ_printf(m, " .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
#ifdef CONFIG_SMP
- SEQ_printf(m, " .%-30s: %ld\n", "runnable_weight", cfs_rq->runnable_weight);
SEQ_printf(m, " .%-30s: %lu\n", "load_avg",
cfs_rq->avg.load_avg);
- SEQ_printf(m, " .%-30s: %lu\n", "runnable_load_avg",
- cfs_rq->avg.runnable_load_avg);
+ SEQ_printf(m, " .%-30s: %lu\n", "runnable_avg",
+ cfs_rq->avg.runnable_avg);
SEQ_printf(m, " .%-30s: %lu\n", "util_avg",
cfs_rq->avg.util_avg);
SEQ_printf(m, " .%-30s: %u\n", "util_est_enqueued",
@@ -537,8 +535,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
cfs_rq->removed.load_avg);
SEQ_printf(m, " .%-30s: %ld\n", "removed.util_avg",
cfs_rq->removed.util_avg);
- SEQ_printf(m, " .%-30s: %ld\n", "removed.runnable_sum",
- cfs_rq->removed.runnable_sum);
+ SEQ_printf(m, " .%-30s: %ld\n", "removed.runnable_avg",
+ cfs_rq->removed.runnable_avg);
#ifdef CONFIG_FAIR_GROUP_SCHED
SEQ_printf(m, " .%-30s: %lu\n", "tg_load_avg_contrib",
cfs_rq->tg_load_avg_contrib);
@@ -947,13 +945,12 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
"nr_involuntary_switches", (long long)p->nivcsw);
P(se.load.weight);
- P(se.runnable_weight);
#ifdef CONFIG_SMP
P(se.avg.load_sum);
- P(se.avg.runnable_load_sum);
+ P(se.avg.runnable_sum);
P(se.avg.util_sum);
P(se.avg.load_avg);
- P(se.avg.runnable_load_avg);
+ P(se.avg.runnable_avg);
P(se.avg.util_avg);
P(se.avg.last_update_time);
P(se.avg.util_est.ewma);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c1217bfe5e81..d7fb20adabeb 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -86,6 +86,19 @@ static unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
+int sched_thermal_decay_shift;
+static int __init setup_sched_thermal_decay_shift(char *str)
+{
+ int _shift = 0;
+
+ if (kstrtoint(str, 0, &_shift))
+ pr_warn("Unable to set scheduler thermal pressure decay shift parameter\n");
+
+ sched_thermal_decay_shift = clamp(_shift, 0, 10);
+ return 1;
+}
+__setup("sched_thermal_decay_shift=", setup_sched_thermal_decay_shift);
+
#ifdef CONFIG_SMP
/*
* For asym packing, by default the lower numbered CPU has higher priority.
@@ -741,9 +754,7 @@ void init_entity_runnable_average(struct sched_entity *se)
* nothing has been attached to the task group yet.
*/
if (entity_is_task(se))
- sa->runnable_load_avg = sa->load_avg = scale_load_down(se->load.weight);
-
- se->runnable_weight = se->load.weight;
+ sa->load_avg = scale_load_down(se->load.weight);
/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */
}
@@ -796,6 +807,8 @@ void post_init_entity_util_avg(struct task_struct *p)
}
}
+ sa->runnable_avg = cpu_scale;
+
if (p->sched_class != &fair_sched_class) {
/*
* For !fair tasks do:
@@ -1473,36 +1486,51 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4;
}
-static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq);
-
-static unsigned long cpu_runnable_load(struct rq *rq)
-{
- return cfs_rq_runnable_load_avg(&rq->cfs);
-}
+/*
+ * 'numa_type' describes the node at the moment of load balancing.
+ */
+enum numa_type {
+ /* The node has spare capacity that can be used to run more tasks. */
+ node_has_spare = 0,
+ /*
+ * The node is fully used and the tasks don't compete for more CPU
+ * cycles. Nevertheless, some tasks might wait before running.
+ */
+ node_fully_busy,
+ /*
+ * The node is overloaded and can't provide expected CPU cycles to all
+ * tasks.
+ */
+ node_overloaded
+};
/* Cached statistics for all CPUs within a node */
struct numa_stats {
unsigned long load;
-
+ unsigned long util;
/* Total compute capacity of CPUs on a node */
unsigned long compute_capacity;
+ unsigned int nr_running;
+ unsigned int weight;
+ enum numa_type node_type;
+ int idle_cpu;
};
-/*
- * XXX borrowed from update_sg_lb_stats
- */
-static void update_numa_stats(struct numa_stats *ns, int nid)
+static inline bool is_core_idle(int cpu)
{
- int cpu;
+#ifdef CONFIG_SCHED_SMT
+ int sibling;
- memset(ns, 0, sizeof(*ns));
- for_each_cpu(cpu, cpumask_of_node(nid)) {
- struct rq *rq = cpu_rq(cpu);
+ for_each_cpu(sibling, cpu_smt_mask(cpu)) {
+ if (cpu == sibling)
+ continue;
- ns->load += cpu_runnable_load(rq);
- ns->compute_capacity += capacity_of(cpu);
+ if (!idle_cpu(cpu))
+ return false;
}
+#endif
+ return true;
}
struct task_numa_env {
@@ -1521,20 +1549,128 @@ struct task_numa_env {
int best_cpu;
};
+static unsigned long cpu_load(struct rq *rq);
+static unsigned long cpu_util(int cpu);
+static inline long adjust_numa_imbalance(int imbalance, int src_nr_running);
+
+static inline enum
+numa_type numa_classify(unsigned int imbalance_pct,
+ struct numa_stats *ns)
+{
+ if ((ns->nr_running > ns->weight) &&
+ ((ns->compute_capacity * 100) < (ns->util * imbalance_pct)))
+ return node_overloaded;
+
+ if ((ns->nr_running < ns->weight) ||
+ ((ns->compute_capacity * 100) > (ns->util * imbalance_pct)))
+ return node_has_spare;
+
+ return node_fully_busy;
+}
+
+#ifdef CONFIG_SCHED_SMT
+/* Forward declarations of select_idle_sibling helpers */
+static inline bool test_idle_cores(int cpu, bool def);
+static inline int numa_idle_core(int idle_core, int cpu)
+{
+ if (!static_branch_likely(&sched_smt_present) ||
+ idle_core >= 0 || !test_idle_cores(cpu, false))
+ return idle_core;
+
+ /*
+ * Prefer cores instead of packing HT siblings
+ * and triggering future load balancing.
+ */
+ if (is_core_idle(cpu))
+ idle_core = cpu;
+
+ return idle_core;
+}
+#else
+static inline int numa_idle_core(int idle_core, int cpu)
+{
+ return idle_core;
+}
+#endif
+
+/*
+ * Gather all necessary information to make NUMA balancing placement
+ * decisions that are compatible with standard load balancer. This
+ * borrows code and logic from update_sg_lb_stats but sharing a
+ * common implementation is impractical.
+ */
+static void update_numa_stats(struct task_numa_env *env,
+ struct numa_stats *ns, int nid,
+ bool find_idle)
+{
+ int cpu, idle_core = -1;
+
+ memset(ns, 0, sizeof(*ns));
+ ns->idle_cpu = -1;
+
+ rcu_read_lock();
+ for_each_cpu(cpu, cpumask_of_node(nid)) {
+ struct rq *rq = cpu_rq(cpu);
+
+ ns->load += cpu_load(rq);
+ ns->util += cpu_util(cpu);
+ ns->nr_running += rq->cfs.h_nr_running;
+ ns->compute_capacity += capacity_of(cpu);
+
+ if (find_idle && !rq->nr_running && idle_cpu(cpu)) {
+ if (READ_ONCE(rq->numa_migrate_on) ||
+ !cpumask_test_cpu(cpu, env->p->cpus_ptr))
+ continue;
+
+ if (ns->idle_cpu == -1)
+ ns->idle_cpu = cpu;
+
+ idle_core = numa_idle_core(idle_core, cpu);
+ }
+ }
+ rcu_read_unlock();
+
+ ns->weight = cpumask_weight(cpumask_of_node(nid));
+
+ ns->node_type = numa_classify(env->imbalance_pct, ns);
+
+ if (idle_core >= 0)
+ ns->idle_cpu = idle_core;
+}
+
static void task_numa_assign(struct task_numa_env *env,
struct task_struct *p, long imp)
{
struct rq *rq = cpu_rq(env->dst_cpu);
- /* Bail out if run-queue part of active NUMA balance. */
- if (xchg(&rq->numa_migrate_on, 1))
+ /* Check if run-queue part of active NUMA balance. */
+ if (env->best_cpu != env->dst_cpu && xchg(&rq->numa_migrate_on, 1)) {
+ int cpu;
+ int start = env->dst_cpu;
+
+ /* Find alternative idle CPU. */
+ for_each_cpu_wrap(cpu, cpumask_of_node(env->dst_nid), start) {
+ if (cpu == env->best_cpu || !idle_cpu(cpu) ||
+ !cpumask_test_cpu(cpu, env->p->cpus_ptr)) {
+ continue;
+ }
+
+ env->dst_cpu = cpu;
+ rq = cpu_rq(env->dst_cpu);
+ if (!xchg(&rq->numa_migrate_on, 1))
+ goto assign;
+ }
+
+ /* Failed to find an alternative idle CPU */
return;
+ }
+assign:
/*
* Clear previous best_cpu/rq numa-migrate flag, since task now
* found a better CPU to move/swap.
*/
- if (env->best_cpu != -1) {
+ if (env->best_cpu != -1 && env->best_cpu != env->dst_cpu) {
rq = cpu_rq(env->best_cpu);
WRITE_ONCE(rq->numa_migrate_on, 0);
}
@@ -1590,7 +1726,7 @@ static bool load_too_imbalanced(long src_load, long dst_load,
* into account that it might be best if task running on the dst_cpu should
* be exchanged with the source task
*/
-static void task_numa_compare(struct task_numa_env *env,
+static bool task_numa_compare(struct task_numa_env *env,
long taskimp, long groupimp, bool maymove)
{
struct numa_group *cur_ng, *p_ng = deref_curr_numa_group(env->p);
@@ -1601,9 +1737,10 @@ static void task_numa_compare(struct task_numa_env *env,
int dist = env->dist;
long moveimp = imp;
long load;
+ bool stopsearch = false;
if (READ_ONCE(dst_rq->numa_migrate_on))
- return;
+ return false;
rcu_read_lock();
cur = rcu_dereference(dst_rq->curr);
@@ -1614,8 +1751,10 @@ static void task_numa_compare(struct task_numa_env *env,
* Because we have preemption enabled we can get migrated around and
* end try selecting ourselves (current == env->p) as a swap candidate.
*/
- if (cur == env->p)
+ if (cur == env->p) {
+ stopsearch = true;
goto unlock;
+ }
if (!cur) {
if (maymove && moveimp >= env->best_imp)
@@ -1624,18 +1763,27 @@ static void task_numa_compare(struct task_numa_env *env,
goto unlock;
}
+ /* Skip this swap candidate if cannot move to the source cpu. */
+ if (!cpumask_test_cpu(env->src_cpu, cur->cpus_ptr))
+ goto unlock;
+
+ /*
+ * Skip this swap candidate if it is not moving to its preferred
+ * node and the best task is.
+ */
+ if (env->best_task &&
+ env->best_task->numa_preferred_nid == env->src_nid &&
+ cur->numa_preferred_nid != env->src_nid) {
+ goto unlock;
+ }
+
/*
* "imp" is the fault differential for the source task between the
* source and destination node. Calculate the total differential for
* the source task and potential destination task. The more negative
* the value is, the more remote accesses that would be expected to
* be incurred if the tasks were swapped.
- */
- /* Skip this swap candidate if cannot move to the source cpu */
- if (!cpumask_test_cpu(env->src_cpu, cur->cpus_ptr))
- goto unlock;
-
- /*
+ *
* If dst and source tasks are in the same NUMA group, or not
* in any group then look only at task weights.
*/
@@ -1662,6 +1810,19 @@ static void task_numa_compare(struct task_numa_env *env,
task_weight(cur, env->dst_nid, dist);
}
+ /* Discourage picking a task already on its preferred node */
+ if (cur->numa_preferred_nid == env->dst_nid)
+ imp -= imp / 16;
+
+ /*
+ * Encourage picking a task that moves to its preferred node.
+ * This potentially makes imp larger than it's maximum of
+ * 1998 (see SMALLIMP and task_weight for why) but in this
+ * case, it does not matter.
+ */
+ if (cur->numa_preferred_nid == env->src_nid)
+ imp += imp / 8;
+
if (maymove && moveimp > imp && moveimp > env->best_imp) {
imp = moveimp;
cur = NULL;
@@ -1669,6 +1830,15 @@ static void task_numa_compare(struct task_numa_env *env,
}
/*
+ * Prefer swapping with a task moving to its preferred node over a
+ * task that is not.
+ */
+ if (env->best_task && cur->numa_preferred_nid == env->src_nid &&
+ env->best_task->numa_preferred_nid != env->src_nid) {
+ goto assign;
+ }
+
+ /*
* If the NUMA importance is less than SMALLIMP,
* task migration might only result in ping pong
* of tasks and also hurt performance due to cache
@@ -1691,42 +1861,95 @@ static void task_numa_compare(struct task_numa_env *env,
goto unlock;
assign:
- /*
- * One idle CPU per node is evaluated for a task numa move.
- * Call select_idle_sibling to maybe find a better one.
- */
+ /* Evaluate an idle CPU for a task numa move. */
if (!cur) {
+ int cpu = env->dst_stats.idle_cpu;
+
+ /* Nothing cached so current CPU went idle since the search. */
+ if (cpu < 0)
+ cpu = env->dst_cpu;
+
/*
- * select_idle_siblings() uses an per-CPU cpumask that
- * can be used from IRQ context.
+ * If the CPU is no longer truly idle and the previous best CPU
+ * is, keep using it.
*/
- local_irq_disable();
- env->dst_cpu = select_idle_sibling(env->p, env->src_cpu,
- env->dst_cpu);
- local_irq_enable();
+ if (!idle_cpu(cpu) && env->best_cpu >= 0 &&
+ idle_cpu(env->best_cpu)) {
+ cpu = env->best_cpu;
+ }
+
+ env->dst_cpu = cpu;
}
task_numa_assign(env, cur, imp);
+
+ /*
+ * If a move to idle is allowed because there is capacity or load
+ * balance improves then stop the search. While a better swap
+ * candidate may exist, a search is not free.
+ */
+ if (maymove && !cur && env->best_cpu >= 0 && idle_cpu(env->best_cpu))
+ stopsearch = true;
+
+ /*
+ * If a swap candidate must be identified and the current best task
+ * moves its preferred node then stop the search.
+ */
+ if (!maymove && env->best_task &&
+ env->best_task->numa_preferred_nid == env->src_nid) {
+ stopsearch = true;
+ }
unlock:
rcu_read_unlock();
+
+ return stopsearch;
}
static void task_numa_find_cpu(struct task_numa_env *env,
long taskimp, long groupimp)
{
- long src_load, dst_load, load;
bool maymove = false;
int cpu;
- load = task_h_load(env->p);
- dst_load = env->dst_stats.load + load;
- src_load = env->src_stats.load - load;
-
/*
- * If the improvement from just moving env->p direction is better
- * than swapping tasks around, check if a move is possible.
+ * If dst node has spare capacity, then check if there is an
+ * imbalance that would be overruled by the load balancer.
*/
- maymove = !load_too_imbalanced(src_load, dst_load, env);
+ if (env->dst_stats.node_type == node_has_spare) {
+ unsigned int imbalance;
+ int src_running, dst_running;
+
+ /*
+ * Would movement cause an imbalance? Note that if src has
+ * more running tasks that the imbalance is ignored as the
+ * move improves the imbalance from the perspective of the
+ * CPU load balancer.
+ * */
+ src_running = env->src_stats.nr_running - 1;
+ dst_running = env->dst_stats.nr_running + 1;
+ imbalance = max(0, dst_running - src_running);
+ imbalance = adjust_numa_imbalance(imbalance, src_running);
+
+ /* Use idle CPU if there is no imbalance */
+ if (!imbalance) {
+ maymove = true;
+ if (env->dst_stats.idle_cpu >= 0) {
+ env->dst_cpu = env->dst_stats.idle_cpu;
+ task_numa_assign(env, NULL, 0);
+ return;
+ }
+ }
+ } else {
+ long src_load, dst_load, load;
+ /*
+ * If the improvement from just moving env->p direction is better
+ * than swapping tasks around, check if a move is possible.
+ */
+ load = task_h_load(env->p);
+ dst_load = env->dst_stats.load + load;
+ src_load = env->src_stats.load - load;
+ maymove = !load_too_imbalanced(src_load, dst_load, env);
+ }
for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) {
/* Skip this CPU if the source task cannot migrate */
@@ -1734,7 +1957,8 @@ static void task_numa_find_cpu(struct task_numa_env *env,
continue;
env->dst_cpu = cpu;
- task_numa_compare(env, taskimp, groupimp, maymove);
+ if (task_numa_compare(env, taskimp, groupimp, maymove))
+ break;
}
}
@@ -1788,10 +2012,10 @@ static int task_numa_migrate(struct task_struct *p)
dist = env.dist = node_distance(env.src_nid, env.dst_nid);
taskweight = task_weight(p, env.src_nid, dist);
groupweight = group_weight(p, env.src_nid, dist);
- update_numa_stats(&env.src_stats, env.src_nid);
+ update_numa_stats(&env, &env.src_stats, env.src_nid, false);
taskimp = task_weight(p, env.dst_nid, dist) - taskweight;
groupimp = group_weight(p, env.dst_nid, dist) - groupweight;
- update_numa_stats(&env.dst_stats, env.dst_nid);
+ update_numa_stats(&env, &env.dst_stats, env.dst_nid, true);
/* Try to find a spot on the preferred nid. */
task_numa_find_cpu(&env, taskimp, groupimp);
@@ -1824,7 +2048,7 @@ static int task_numa_migrate(struct task_struct *p)
env.dist = dist;
env.dst_nid = nid;
- update_numa_stats(&env.dst_stats, env.dst_nid);
+ update_numa_stats(&env, &env.dst_stats, env.dst_nid, true);
task_numa_find_cpu(&env, taskimp, groupimp);
}
}
@@ -1848,15 +2072,17 @@ static int task_numa_migrate(struct task_struct *p)
}
/* No better CPU than the current one was found. */
- if (env.best_cpu == -1)
+ if (env.best_cpu == -1) {
+ trace_sched_stick_numa(p, env.src_cpu, NULL, -1);
return -EAGAIN;
+ }
best_rq = cpu_rq(env.best_cpu);
if (env.best_task == NULL) {
ret = migrate_task_to(p, env.best_cpu);
WRITE_ONCE(best_rq->numa_migrate_on, 0);
if (ret != 0)
- trace_sched_stick_numa(p, env.src_cpu, env.best_cpu);
+ trace_sched_stick_numa(p, env.src_cpu, NULL, env.best_cpu);
return ret;
}
@@ -1864,7 +2090,7 @@ static int task_numa_migrate(struct task_struct *p)
WRITE_ONCE(best_rq->numa_migrate_on, 0);
if (ret != 0)
- trace_sched_stick_numa(p, env.src_cpu, task_cpu(env.best_task));
+ trace_sched_stick_numa(p, env.src_cpu, env.best_task, env.best_cpu);
put_task_struct(env.best_task);
return ret;
}
@@ -2835,25 +3061,6 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
#ifdef CONFIG_SMP
static inline void
-enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
- cfs_rq->runnable_weight += se->runnable_weight;
-
- cfs_rq->avg.runnable_load_avg += se->avg.runnable_load_avg;
- cfs_rq->avg.runnable_load_sum += se_runnable(se) * se->avg.runnable_load_sum;
-}
-
-static inline void
-dequeue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
- cfs_rq->runnable_weight -= se->runnable_weight;
-
- sub_positive(&cfs_rq->avg.runnable_load_avg, se->avg.runnable_load_avg);
- sub_positive(&cfs_rq->avg.runnable_load_sum,
- se_runnable(se) * se->avg.runnable_load_sum);
-}
-
-static inline void
enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
cfs_rq->avg.load_avg += se->avg.load_avg;
@@ -2868,28 +3075,22 @@ dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
}
#else
static inline void
-enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
-static inline void
-dequeue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
-static inline void
enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
static inline void
dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
#endif
static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
- unsigned long weight, unsigned long runnable)
+ unsigned long weight)
{
if (se->on_rq) {
/* commit outstanding execution time */
if (cfs_rq->curr == se)
update_curr(cfs_rq);
account_entity_dequeue(cfs_rq, se);
- dequeue_runnable_load_avg(cfs_rq, se);
}
dequeue_load_avg(cfs_rq, se);
- se->runnable_weight = runnable;
update_load_set(&se->load, weight);
#ifdef CONFIG_SMP
@@ -2897,16 +3098,13 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
u32 divider = LOAD_AVG_MAX - 1024 + se->avg.period_contrib;
se->avg.load_avg = div_u64(se_weight(se) * se->avg.load_sum, divider);
- se->avg.runnable_load_avg =
- div_u64(se_runnable(se) * se->avg.runnable_load_sum, divider);
} while (0);
#endif
enqueue_load_avg(cfs_rq, se);
- if (se->on_rq) {
+ if (se->on_rq)
account_entity_enqueue(cfs_rq, se);
- enqueue_runnable_load_avg(cfs_rq, se);
- }
+
}
void reweight_task(struct task_struct *p, int prio)
@@ -2916,7 +3114,7 @@ void reweight_task(struct task_struct *p, int prio)
struct load_weight *load = &se->load;
unsigned long weight = scale_load(sched_prio_to_weight[prio]);
- reweight_entity(cfs_rq, se, weight, weight);
+ reweight_entity(cfs_rq, se, weight);
load->inv_weight = sched_prio_to_wmult[prio];
}
@@ -3028,50 +3226,6 @@ static long calc_group_shares(struct cfs_rq *cfs_rq)
*/
return clamp_t(long, shares, MIN_SHARES, tg_shares);
}
-
-/*
- * This calculates the effective runnable weight for a group entity based on
- * the group entity weight calculated above.
- *
- * Because of the above approximation (2), our group entity weight is
- * an load_avg based ratio (3). This means that it includes blocked load and
- * does not represent the runnable weight.
- *
- * Approximate the group entity's runnable weight per ratio from the group
- * runqueue:
- *
- * grq->avg.runnable_load_avg
- * ge->runnable_weight = ge->load.weight * -------------------------- (7)
- * grq->avg.load_avg
- *
- * However, analogous to above, since the avg numbers are slow, this leads to
- * transients in the from-idle case. Instead we use:
- *
- * ge->runnable_weight = ge->load.weight *
- *
- * max(grq->avg.runnable_load_avg, grq->runnable_weight)
- * ----------------------------------------------------- (8)
- * max(grq->avg.load_avg, grq->load.weight)
- *
- * Where these max() serve both to use the 'instant' values to fix the slow
- * from-idle and avoid the /0 on to-idle, similar to (6).
- */
-static long calc_group_runnable(struct cfs_rq *cfs_rq, long shares)
-{
- long runnable, load_avg;
-
- load_avg = max(cfs_rq->avg.load_avg,
- scale_load_down(cfs_rq->load.weight));
-
- runnable = max(cfs_rq->avg.runnable_load_avg,
- scale_load_down(cfs_rq->runnable_weight));
-
- runnable *= shares;
- if (load_avg)
- runnable /= load_avg;
-
- return clamp_t(long, runnable, MIN_SHARES, shares);
-}
#endif /* CONFIG_SMP */
static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
@@ -3083,7 +3237,7 @@ static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
static void update_cfs_group(struct sched_entity *se)
{
struct cfs_rq *gcfs_rq = group_cfs_rq(se);
- long shares, runnable;
+ long shares;
if (!gcfs_rq)
return;
@@ -3092,16 +3246,15 @@ static void update_cfs_group(struct sched_entity *se)
return;
#ifndef CONFIG_SMP
- runnable = shares = READ_ONCE(gcfs_rq->tg->shares);
+ shares = READ_ONCE(gcfs_rq->tg->shares);
if (likely(se->load.weight == shares))
return;
#else
shares = calc_group_shares(gcfs_rq);
- runnable = calc_group_runnable(gcfs_rq, shares);
#endif
- reweight_entity(cfs_rq_of(se), se, shares, runnable);
+ reweight_entity(cfs_rq_of(se), se, shares);
}
#else /* CONFIG_FAIR_GROUP_SCHED */
@@ -3226,11 +3379,11 @@ void set_task_rq_fair(struct sched_entity *se,
* _IFF_ we look at the pure running and runnable sums. Because they
* represent the very same entity, just at different points in the hierarchy.
*
- * Per the above update_tg_cfs_util() is trivial and simply copies the running
- * sum over (but still wrong, because the group entity and group rq do not have
- * their PELT windows aligned).
+ * Per the above update_tg_cfs_util() and update_tg_cfs_runnable() are trivial
+ * and simply copies the running/runnable sum over (but still wrong, because
+ * the group entity and group rq do not have their PELT windows aligned).
*
- * However, update_tg_cfs_runnable() is more complex. So we have:
+ * However, update_tg_cfs_load() is more complex. So we have:
*
* ge->avg.load_avg = ge->load.weight * ge->avg.runnable_avg (2)
*
@@ -3313,9 +3466,35 @@ update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq
static inline void
update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
{
+ long delta = gcfs_rq->avg.runnable_avg - se->avg.runnable_avg;
+
+ /* Nothing to update */
+ if (!delta)
+ return;
+
+ /*
+ * The relation between sum and avg is:
+ *
+ * LOAD_AVG_MAX - 1024 + sa->period_contrib
+ *
+ * however, the PELT windows are not aligned between grq and gse.
+ */
+
+ /* Set new sched_entity's runnable */
+ se->avg.runnable_avg = gcfs_rq->avg.runnable_avg;
+ se->avg.runnable_sum = se->avg.runnable_avg * LOAD_AVG_MAX;
+
+ /* Update parent cfs_rq runnable */
+ add_positive(&cfs_rq->avg.runnable_avg, delta);
+ cfs_rq->avg.runnable_sum = cfs_rq->avg.runnable_avg * LOAD_AVG_MAX;
+}
+
+static inline void
+update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
+{
long delta_avg, running_sum, runnable_sum = gcfs_rq->prop_runnable_sum;
- unsigned long runnable_load_avg, load_avg;
- u64 runnable_load_sum, load_sum = 0;
+ unsigned long load_avg;
+ u64 load_sum = 0;
s64 delta_sum;
if (!runnable_sum)
@@ -3363,20 +3542,6 @@ update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cf
se->avg.load_avg = load_avg;
add_positive(&cfs_rq->avg.load_avg, delta_avg);
add_positive(&cfs_rq->avg.load_sum, delta_sum);
-
- runnable_load_sum = (s64)se_runnable(se) * runnable_sum;
- runnable_load_avg = div_s64(runnable_load_sum, LOAD_AVG_MAX);
-
- if (se->on_rq) {
- delta_sum = runnable_load_sum -
- se_weight(se) * se->avg.runnable_load_sum;
- delta_avg = runnable_load_avg - se->avg.runnable_load_avg;
- add_positive(&cfs_rq->avg.runnable_load_avg, delta_avg);
- add_positive(&cfs_rq->avg.runnable_load_sum, delta_sum);
- }
-
- se->avg.runnable_load_sum = runnable_sum;
- se->avg.runnable_load_avg = runnable_load_avg;
}
static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum)
@@ -3405,6 +3570,7 @@ static inline int propagate_entity_load_avg(struct sched_entity *se)
update_tg_cfs_util(cfs_rq, se, gcfs_rq);
update_tg_cfs_runnable(cfs_rq, se, gcfs_rq);
+ update_tg_cfs_load(cfs_rq, se, gcfs_rq);
trace_pelt_cfs_tp(cfs_rq);
trace_pelt_se_tp(se);
@@ -3474,7 +3640,7 @@ static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum
static inline int
update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
{
- unsigned long removed_load = 0, removed_util = 0, removed_runnable_sum = 0;
+ unsigned long removed_load = 0, removed_util = 0, removed_runnable = 0;
struct sched_avg *sa = &cfs_rq->avg;
int decayed = 0;
@@ -3485,7 +3651,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
raw_spin_lock(&cfs_rq->removed.lock);
swap(cfs_rq->removed.util_avg, removed_util);
swap(cfs_rq->removed.load_avg, removed_load);
- swap(cfs_rq->removed.runnable_sum, removed_runnable_sum);
+ swap(cfs_rq->removed.runnable_avg, removed_runnable);
cfs_rq->removed.nr = 0;
raw_spin_unlock(&cfs_rq->removed.lock);
@@ -3497,7 +3663,16 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
sub_positive(&sa->util_avg, r);
sub_positive(&sa->util_sum, r * divider);
- add_tg_cfs_propagate(cfs_rq, -(long)removed_runnable_sum);
+ r = removed_runnable;
+ sub_positive(&sa->runnable_avg, r);
+ sub_positive(&sa->runnable_sum, r * divider);
+
+ /*
+ * removed_runnable is the unweighted version of removed_load so we
+ * can use it to estimate removed_load_sum.
+ */
+ add_tg_cfs_propagate(cfs_rq,
+ -(long)(removed_runnable * divider) >> SCHED_CAPACITY_SHIFT);
decayed = 1;
}
@@ -3542,17 +3717,19 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s
*/
se->avg.util_sum = se->avg.util_avg * divider;
+ se->avg.runnable_sum = se->avg.runnable_avg * divider;
+
se->avg.load_sum = divider;
if (se_weight(se)) {
se->avg.load_sum =
div_u64(se->avg.load_avg * se->avg.load_sum, se_weight(se));
}
- se->avg.runnable_load_sum = se->avg.load_sum;
-
enqueue_load_avg(cfs_rq, se);
cfs_rq->avg.util_avg += se->avg.util_avg;
cfs_rq->avg.util_sum += se->avg.util_sum;
+ cfs_rq->avg.runnable_avg += se->avg.runnable_avg;
+ cfs_rq->avg.runnable_sum += se->avg.runnable_sum;
add_tg_cfs_propagate(cfs_rq, se->avg.load_sum);
@@ -3574,6 +3751,8 @@ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s
dequeue_load_avg(cfs_rq, se);
sub_positive(&cfs_rq->avg.util_avg, se->avg.util_avg);
sub_positive(&cfs_rq->avg.util_sum, se->avg.util_sum);
+ sub_positive(&cfs_rq->avg.runnable_avg, se->avg.runnable_avg);
+ sub_positive(&cfs_rq->avg.runnable_sum, se->avg.runnable_sum);
add_tg_cfs_propagate(cfs_rq, -se->avg.load_sum);
@@ -3680,13 +3859,13 @@ static void remove_entity_load_avg(struct sched_entity *se)
++cfs_rq->removed.nr;
cfs_rq->removed.util_avg += se->avg.util_avg;
cfs_rq->removed.load_avg += se->avg.load_avg;
- cfs_rq->removed.runnable_sum += se->avg.load_sum; /* == runnable_sum */
+ cfs_rq->removed.runnable_avg += se->avg.runnable_avg;
raw_spin_unlock_irqrestore(&cfs_rq->removed.lock, flags);
}
-static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq)
+static inline unsigned long cfs_rq_runnable_avg(struct cfs_rq *cfs_rq)
{
- return cfs_rq->avg.runnable_load_avg;
+ return cfs_rq->avg.runnable_avg;
}
static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq)
@@ -3957,6 +4136,7 @@ static inline void check_schedstat_required(void)
#endif
}
+static inline bool cfs_bandwidth_used(void);
/*
* MIGRATION
@@ -4021,8 +4201,8 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
* - Add its new weight to cfs_rq->load.weight
*/
update_load_avg(cfs_rq, se, UPDATE_TG | DO_ATTACH);
+ se_update_runnable(se);
update_cfs_group(se);
- enqueue_runnable_load_avg(cfs_rq, se);
account_entity_enqueue(cfs_rq, se);
if (flags & ENQUEUE_WAKEUP)
@@ -4035,10 +4215,16 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
__enqueue_entity(cfs_rq, se);
se->on_rq = 1;
- if (cfs_rq->nr_running == 1) {
+ /*
+ * When bandwidth control is enabled, cfs might have been removed
+ * because of a parent been throttled but cfs->nr_running > 1. Try to
+ * add it unconditionnally.
+ */
+ if (cfs_rq->nr_running == 1 || cfs_bandwidth_used())
list_add_leaf_cfs_rq(cfs_rq);
+
+ if (cfs_rq->nr_running == 1)
check_enqueue_throttle(cfs_rq);
- }
}
static void __clear_buddies_last(struct sched_entity *se)
@@ -4105,7 +4291,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
* of its group cfs_rq.
*/
update_load_avg(cfs_rq, se, UPDATE_TG);
- dequeue_runnable_load_avg(cfs_rq, se);
+ se_update_runnable(se);
update_stats_dequeue(cfs_rq, se, flags);
@@ -4541,8 +4727,13 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
if (!se->on_rq)
break;
- if (dequeue)
+ if (dequeue) {
dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP);
+ } else {
+ update_load_avg(qcfs_rq, se, 0);
+ se_update_runnable(se);
+ }
+
qcfs_rq->h_nr_running -= task_delta;
qcfs_rq->idle_h_nr_running -= idle_task_delta;
@@ -4610,8 +4801,13 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
enqueue = 0;
cfs_rq = cfs_rq_of(se);
- if (enqueue)
+ if (enqueue) {
enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
+ } else {
+ update_load_avg(cfs_rq, se, 0);
+ se_update_runnable(se);
+ }
+
cfs_rq->h_nr_running += task_delta;
cfs_rq->idle_h_nr_running += idle_task_delta;
@@ -4619,11 +4815,22 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
break;
}
- assert_list_leaf_cfs_rq(rq);
-
if (!se)
add_nr_running(rq, task_delta);
+ /*
+ * The cfs_rq_throttled() breaks in the above iteration can result in
+ * incomplete leaf list maintenance, resulting in triggering the
+ * assertion below.
+ */
+ for_each_sched_entity(se) {
+ cfs_rq = cfs_rq_of(se);
+
+ list_add_leaf_cfs_rq(cfs_rq);
+ }
+
+ assert_list_leaf_cfs_rq(rq);
+
/* Determine whether we need to wake up potentially idle CPU: */
if (rq->curr == rq->idle && rq->cfs.nr_running)
resched_curr(rq);
@@ -5258,32 +5465,32 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
cfs_rq = cfs_rq_of(se);
enqueue_entity(cfs_rq, se, flags);
- /*
- * end evaluation on encountering a throttled cfs_rq
- *
- * note: in the case of encountering a throttled cfs_rq we will
- * post the final h_nr_running increment below.
- */
- if (cfs_rq_throttled(cfs_rq))
- break;
cfs_rq->h_nr_running++;
cfs_rq->idle_h_nr_running += idle_h_nr_running;
+ /* end evaluation on encountering a throttled cfs_rq */
+ if (cfs_rq_throttled(cfs_rq))
+ goto enqueue_throttle;
+
flags = ENQUEUE_WAKEUP;
}
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
+
+ update_load_avg(cfs_rq, se, UPDATE_TG);
+ se_update_runnable(se);
+ update_cfs_group(se);
+
cfs_rq->h_nr_running++;
cfs_rq->idle_h_nr_running += idle_h_nr_running;
+ /* end evaluation on encountering a throttled cfs_rq */
if (cfs_rq_throttled(cfs_rq))
- break;
-
- update_load_avg(cfs_rq, se, UPDATE_TG);
- update_cfs_group(se);
+ goto enqueue_throttle;
}
+enqueue_throttle:
if (!se) {
add_nr_running(rq, 1);
/*
@@ -5344,17 +5551,13 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
cfs_rq = cfs_rq_of(se);
dequeue_entity(cfs_rq, se, flags);
- /*
- * end evaluation on encountering a throttled cfs_rq
- *
- * note: in the case of encountering a throttled cfs_rq we will
- * post the final h_nr_running decrement below.
- */
- if (cfs_rq_throttled(cfs_rq))
- break;
cfs_rq->h_nr_running--;
cfs_rq->idle_h_nr_running -= idle_h_nr_running;
+ /* end evaluation on encountering a throttled cfs_rq */
+ if (cfs_rq_throttled(cfs_rq))
+ goto dequeue_throttle;
+
/* Don't dequeue parent if it has other entities besides us */
if (cfs_rq->load.weight) {
/* Avoid re-evaluating load for this entity: */
@@ -5372,16 +5575,21 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
+
+ update_load_avg(cfs_rq, se, UPDATE_TG);
+ se_update_runnable(se);
+ update_cfs_group(se);
+
cfs_rq->h_nr_running--;
cfs_rq->idle_h_nr_running -= idle_h_nr_running;
+ /* end evaluation on encountering a throttled cfs_rq */
if (cfs_rq_throttled(cfs_rq))
- break;
+ goto dequeue_throttle;
- update_load_avg(cfs_rq, se, UPDATE_TG);
- update_cfs_group(se);
}
+dequeue_throttle:
if (!se)
sub_nr_running(rq, 1);
@@ -5447,6 +5655,29 @@ static unsigned long cpu_load_without(struct rq *rq, struct task_struct *p)
return load;
}
+static unsigned long cpu_runnable(struct rq *rq)
+{
+ return cfs_rq_runnable_avg(&rq->cfs);
+}
+
+static unsigned long cpu_runnable_without(struct rq *rq, struct task_struct *p)
+{
+ struct cfs_rq *cfs_rq;
+ unsigned int runnable;
+
+ /* Task has no contribution or is new */
+ if (cpu_of(rq) != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time))
+ return cpu_runnable(rq);
+
+ cfs_rq = &rq->cfs;
+ runnable = READ_ONCE(cfs_rq->avg.runnable_avg);
+
+ /* Discount task's runnable from CPU's runnable */
+ lsub_positive(&runnable, p->se.avg.runnable_avg);
+
+ return runnable;
+}
+
static unsigned long capacity_of(int cpu)
{
return cpu_rq(cpu)->cpu_capacity;
@@ -5786,10 +6017,12 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int
bool idle = true;
for_each_cpu(cpu, cpu_smt_mask(core)) {
- __cpumask_clear_cpu(cpu, cpus);
- if (!available_idle_cpu(cpu))
+ if (!available_idle_cpu(cpu)) {
idle = false;
+ break;
+ }
}
+ cpumask_andnot(cpus, cpus, cpu_smt_mask(core));
if (idle)
return core;
@@ -5894,6 +6127,40 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t
}
/*
+ * Scan the asym_capacity domain for idle CPUs; pick the first idle one on which
+ * the task fits. If no CPU is big enough, but there are idle ones, try to
+ * maximize capacity.
+ */
+static int
+select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target)
+{
+ unsigned long best_cap = 0;
+ int cpu, best_cpu = -1;
+ struct cpumask *cpus;
+
+ sync_entity_load_avg(&p->se);
+
+ cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
+ cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
+
+ for_each_cpu_wrap(cpu, cpus, target) {
+ unsigned long cpu_cap = capacity_of(cpu);
+
+ if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu))
+ continue;
+ if (task_fits_capacity(p, cpu_cap))
+ return cpu;
+
+ if (cpu_cap > best_cap) {
+ best_cap = cpu_cap;
+ best_cpu = cpu;
+ }
+ }
+
+ return best_cpu;
+}
+
+/*
* Try and locate an idle core/thread in the LLC cache domain.
*/
static int select_idle_sibling(struct task_struct *p, int prev, int target)
@@ -5901,6 +6168,28 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
struct sched_domain *sd;
int i, recent_used_cpu;
+ /*
+ * For asymmetric CPU capacity systems, our domain of interest is
+ * sd_asym_cpucapacity rather than sd_llc.
+ */
+ if (static_branch_unlikely(&sched_asym_cpucapacity)) {
+ sd = rcu_dereference(per_cpu(sd_asym_cpucapacity, target));
+ /*
+ * On an asymmetric CPU capacity system where an exclusive
+ * cpuset defines a symmetric island (i.e. one unique
+ * capacity_orig value through the cpuset), the key will be set
+ * but the CPUs within that cpuset will not have a domain with
+ * SD_ASYM_CPUCAPACITY. These should follow the usual symmetric
+ * capacity path.
+ */
+ if (!sd)
+ goto symmetric;
+
+ i = select_idle_capacity(p, sd, target);
+ return ((unsigned)i < nr_cpumask_bits) ? i : target;
+ }
+
+symmetric:
if (available_idle_cpu(target) || sched_idle_cpu(target))
return target;
@@ -6101,33 +6390,6 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p)
}
/*
- * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
- * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
- *
- * In that case WAKE_AFFINE doesn't make sense and we'll let
- * BALANCE_WAKE sort things out.
- */
-static int wake_cap(struct task_struct *p, int cpu, int prev_cpu)
-{
- long min_cap, max_cap;
-
- if (!static_branch_unlikely(&sched_asym_cpucapacity))
- return 0;
-
- min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu));
- max_cap = cpu_rq(cpu)->rd->max_cpu_capacity;
-
- /* Minimum capacity is close to max, no need to abort wake_affine */
- if (max_cap - min_cap < max_cap >> 3)
- return 0;
-
- /* Bring task utilization in sync with prev_cpu */
- sync_entity_load_avg(&p->se);
-
- return !task_fits_capacity(p, min_cap);
-}
-
-/*
* Predicts what cpu_util(@cpu) would return if @p was migrated (and enqueued)
* to @dst_cpu.
*/
@@ -6391,8 +6653,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
new_cpu = prev_cpu;
}
- want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) &&
- cpumask_test_cpu(cpu, p->cpus_ptr);
+ want_affine = !wake_wide(p) && cpumask_test_cpu(cpu, p->cpus_ptr);
}
rcu_read_lock();
@@ -7506,6 +7767,9 @@ static inline bool others_have_blocked(struct rq *rq)
if (READ_ONCE(rq->avg_dl.util_avg))
return true;
+ if (thermal_load_avg(rq))
+ return true;
+
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
if (READ_ONCE(rq->avg_irq.util_avg))
return true;
@@ -7531,6 +7795,7 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
{
const struct sched_class *curr_class;
u64 now = rq_clock_pelt(rq);
+ unsigned long thermal_pressure;
bool decayed;
/*
@@ -7539,8 +7804,11 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
*/
curr_class = rq->curr->sched_class;
+ thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
+
decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) |
update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) |
+ update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure) |
update_irq_load_avg(rq, 0);
if (others_have_blocked(rq))
@@ -7562,7 +7830,7 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
if (cfs_rq->avg.util_sum)
return false;
- if (cfs_rq->avg.runnable_load_sum)
+ if (cfs_rq->avg.runnable_sum)
return false;
return true;
@@ -7700,7 +7968,8 @@ struct sg_lb_stats {
unsigned long avg_load; /*Avg load across the CPUs of the group */
unsigned long group_load; /* Total load over the CPUs of the group */
unsigned long group_capacity;
- unsigned long group_util; /* Total utilization of the group */
+ unsigned long group_util; /* Total utilization over the CPUs of the group */
+ unsigned long group_runnable; /* Total runnable time over the CPUs of the group */
unsigned int sum_nr_running; /* Nr of tasks running in the group */
unsigned int sum_h_nr_running; /* Nr of CFS tasks running in the group */
unsigned int idle_cpus;
@@ -7763,8 +8032,15 @@ static unsigned long scale_rt_capacity(struct sched_domain *sd, int cpu)
if (unlikely(irq >= max))
return 1;
+ /*
+ * avg_rt.util_avg and avg_dl.util_avg track binary signals
+ * (running and not running) with weights 0 and 1024 respectively.
+ * avg_thermal.load_avg tracks thermal pressure and the weighted
+ * average uses the actual delta max capacity(load).
+ */
used = READ_ONCE(rq->avg_rt.util_avg);
used += READ_ONCE(rq->avg_dl.util_avg);
+ used += thermal_load_avg(rq);
if (unlikely(used >= max))
return 1;
@@ -7921,6 +8197,10 @@ group_has_capacity(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
if (sgs->sum_nr_running < sgs->group_weight)
return true;
+ if ((sgs->group_capacity * imbalance_pct) <
+ (sgs->group_runnable * 100))
+ return false;
+
if ((sgs->group_capacity * 100) >
(sgs->group_util * imbalance_pct))
return true;
@@ -7946,6 +8226,10 @@ group_is_overloaded(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
(sgs->group_util * imbalance_pct))
return true;
+ if ((sgs->group_capacity * imbalance_pct) <
+ (sgs->group_runnable * 100))
+ return true;
+
return false;
}
@@ -8040,6 +8324,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
sgs->group_load += cpu_load(rq);
sgs->group_util += cpu_util(i);
+ sgs->group_runnable += cpu_runnable(rq);
sgs->sum_h_nr_running += rq->cfs.h_nr_running;
nr_running = rq->nr_running;
@@ -8315,6 +8600,7 @@ static inline void update_sg_wakeup_stats(struct sched_domain *sd,
sgs->group_load += cpu_load_without(rq, p);
sgs->group_util += cpu_util_without(i, p);
+ sgs->group_runnable += cpu_runnable_without(rq, p);
local = task_running_on_cpu(i, p);
sgs->sum_h_nr_running += rq->cfs.h_nr_running - local;
@@ -8345,7 +8631,8 @@ static inline void update_sg_wakeup_stats(struct sched_domain *sd,
* Computing avg_load makes sense only when group is fully busy or
* overloaded
*/
- if (sgs->group_type < group_fully_busy)
+ if (sgs->group_type == group_fully_busy ||
+ sgs->group_type == group_overloaded)
sgs->avg_load = (sgs->group_load * SCHED_CAPACITY_SCALE) /
sgs->group_capacity;
}
@@ -8628,6 +8915,21 @@ next_group:
}
}
+static inline long adjust_numa_imbalance(int imbalance, int src_nr_running)
+{
+ unsigned int imbalance_min;
+
+ /*
+ * Allow a small imbalance based on a simple pair of communicating
+ * tasks that remain local when the source domain is almost idle.
+ */
+ imbalance_min = 2;
+ if (src_nr_running <= imbalance_min)
+ return 0;
+
+ return imbalance;
+}
+
/**
* calculate_imbalance - Calculate the amount of imbalance present within the
* groups of a given sched_domain during load balance.
@@ -8724,24 +9026,9 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
}
/* Consider allowing a small imbalance between NUMA groups */
- if (env->sd->flags & SD_NUMA) {
- unsigned int imbalance_min;
-
- /*
- * Compute an allowed imbalance based on a simple
- * pair of communicating tasks that should remain
- * local and ignore them.
- *
- * NOTE: Generally this would have been based on
- * the domain size and this was evaluated. However,
- * the benefit is similar across a range of workloads
- * and machines but scaling by the domain size adds
- * the risk that lower domains have to be rebalanced.
- */
- imbalance_min = 2;
- if (busiest->sum_nr_running <= imbalance_min)
- env->imbalance = 0;
- }
+ if (env->sd->flags & SD_NUMA)
+ env->imbalance = adjust_numa_imbalance(env->imbalance,
+ busiest->sum_nr_running);
return;
}
@@ -9027,6 +9314,14 @@ static struct rq *find_busiest_queue(struct lb_env *env,
case migrate_util:
util = cpu_util(cpu_of(rq));
+ /*
+ * Don't try to pull utilization from a CPU with one
+ * running task. Whatever its utilization, we will fail
+ * detach the task.
+ */
+ if (nr_running <= 1)
+ continue;
+
if (busiest_util < util) {
busiest_util = util;
busiest = rq;
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index bd006b79b360..b647d04d9c8b 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -121,8 +121,8 @@ accumulate_sum(u64 delta, struct sched_avg *sa,
*/
if (periods) {
sa->load_sum = decay_load(sa->load_sum, periods);
- sa->runnable_load_sum =
- decay_load(sa->runnable_load_sum, periods);
+ sa->runnable_sum =
+ decay_load(sa->runnable_sum, periods);
sa->util_sum = decay_load((u64)(sa->util_sum), periods);
/*
@@ -149,7 +149,7 @@ accumulate_sum(u64 delta, struct sched_avg *sa,
if (load)
sa->load_sum += load * contrib;
if (runnable)
- sa->runnable_load_sum += runnable * contrib;
+ sa->runnable_sum += runnable * contrib << SCHED_CAPACITY_SHIFT;
if (running)
sa->util_sum += contrib << SCHED_CAPACITY_SHIFT;
@@ -238,7 +238,7 @@ ___update_load_sum(u64 now, struct sched_avg *sa,
}
static __always_inline void
-___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runnable)
+___update_load_avg(struct sched_avg *sa, unsigned long load)
{
u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib;
@@ -246,7 +246,7 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runna
* Step 2: update *_avg.
*/
sa->load_avg = div_u64(load * sa->load_sum, divider);
- sa->runnable_load_avg = div_u64(runnable * sa->runnable_load_sum, divider);
+ sa->runnable_avg = div_u64(sa->runnable_sum, divider);
WRITE_ONCE(sa->util_avg, sa->util_sum / divider);
}
@@ -254,33 +254,32 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runna
* sched_entity:
*
* task:
- * se_runnable() == se_weight()
+ * se_weight() = se->load.weight
+ * se_runnable() = !!on_rq
*
* group: [ see update_cfs_group() ]
* se_weight() = tg->weight * grq->load_avg / tg->load_avg
- * se_runnable() = se_weight(se) * grq->runnable_load_avg / grq->load_avg
+ * se_runnable() = grq->h_nr_running
*
- * load_sum := runnable_sum
- * load_avg = se_weight(se) * runnable_avg
+ * runnable_sum = se_runnable() * runnable = grq->runnable_sum
+ * runnable_avg = runnable_sum
*
- * runnable_load_sum := runnable_sum
- * runnable_load_avg = se_runnable(se) * runnable_avg
- *
- * XXX collapse load_sum and runnable_load_sum
+ * load_sum := runnable
+ * load_avg = se_weight(se) * load_sum
*
* cfq_rq:
*
+ * runnable_sum = \Sum se->avg.runnable_sum
+ * runnable_avg = \Sum se->avg.runnable_avg
+ *
* load_sum = \Sum se_weight(se) * se->avg.load_sum
* load_avg = \Sum se->avg.load_avg
- *
- * runnable_load_sum = \Sum se_runnable(se) * se->avg.runnable_load_sum
- * runnable_load_avg = \Sum se->avg.runable_load_avg
*/
int __update_load_avg_blocked_se(u64 now, struct sched_entity *se)
{
if (___update_load_sum(now, &se->avg, 0, 0, 0)) {
- ___update_load_avg(&se->avg, se_weight(se), se_runnable(se));
+ ___update_load_avg(&se->avg, se_weight(se));
trace_pelt_se_tp(se);
return 1;
}
@@ -290,10 +289,10 @@ int __update_load_avg_blocked_se(u64 now, struct sched_entity *se)
int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (___update_load_sum(now, &se->avg, !!se->on_rq, !!se->on_rq,
+ if (___update_load_sum(now, &se->avg, !!se->on_rq, se_runnable(se),
cfs_rq->curr == se)) {
- ___update_load_avg(&se->avg, se_weight(se), se_runnable(se));
+ ___update_load_avg(&se->avg, se_weight(se));
cfs_se_util_change(&se->avg);
trace_pelt_se_tp(se);
return 1;
@@ -306,10 +305,10 @@ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq)
{
if (___update_load_sum(now, &cfs_rq->avg,
scale_load_down(cfs_rq->load.weight),
- scale_load_down(cfs_rq->runnable_weight),
+ cfs_rq->h_nr_running,
cfs_rq->curr != NULL)) {
- ___update_load_avg(&cfs_rq->avg, 1, 1);
+ ___update_load_avg(&cfs_rq->avg, 1);
trace_pelt_cfs_tp(cfs_rq);
return 1;
}
@@ -322,9 +321,9 @@ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq)
*
* util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
* util_sum = cpu_scale * load_sum
- * runnable_load_sum = load_sum
+ * runnable_sum = util_sum
*
- * load_avg and runnable_load_avg are not supported and meaningless.
+ * load_avg and runnable_avg are not supported and meaningless.
*
*/
@@ -335,7 +334,7 @@ int update_rt_rq_load_avg(u64 now, struct rq *rq, int running)
running,
running)) {
- ___update_load_avg(&rq->avg_rt, 1, 1);
+ ___update_load_avg(&rq->avg_rt, 1);
trace_pelt_rt_tp(rq);
return 1;
}
@@ -348,7 +347,9 @@ int update_rt_rq_load_avg(u64 now, struct rq *rq, int running)
*
* util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
* util_sum = cpu_scale * load_sum
- * runnable_load_sum = load_sum
+ * runnable_sum = util_sum
+ *
+ * load_avg and runnable_avg are not supported and meaningless.
*
*/
@@ -359,7 +360,7 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
running,
running)) {
- ___update_load_avg(&rq->avg_dl, 1, 1);
+ ___update_load_avg(&rq->avg_dl, 1);
trace_pelt_dl_tp(rq);
return 1;
}
@@ -367,13 +368,46 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
return 0;
}
+#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+/*
+ * thermal:
+ *
+ * load_sum = \Sum se->avg.load_sum but se->avg.load_sum is not tracked
+ *
+ * util_avg and runnable_load_avg are not supported and meaningless.
+ *
+ * Unlike rt/dl utilization tracking that track time spent by a cpu
+ * running a rt/dl task through util_avg, the average thermal pressure is
+ * tracked through load_avg. This is because thermal pressure signal is
+ * time weighted "delta" capacity unlike util_avg which is binary.
+ * "delta capacity" = actual capacity -
+ * capped capacity a cpu due to a thermal event.
+ */
+
+int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+{
+ if (___update_load_sum(now, &rq->avg_thermal,
+ capacity,
+ capacity,
+ capacity)) {
+ ___update_load_avg(&rq->avg_thermal, 1);
+ trace_pelt_thermal_tp(rq);
+ return 1;
+ }
+
+ return 0;
+}
+#endif
+
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
/*
* irq:
*
* util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
* util_sum = cpu_scale * load_sum
- * runnable_load_sum = load_sum
+ * runnable_sum = util_sum
+ *
+ * load_avg and runnable_avg are not supported and meaningless.
*
*/
@@ -410,7 +444,7 @@ int update_irq_load_avg(struct rq *rq, u64 running)
1);
if (ret) {
- ___update_load_avg(&rq->avg_irq, 1, 1);
+ ___update_load_avg(&rq->avg_irq, 1);
trace_pelt_irq_tp(rq);
}
diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h
index afff644da065..eb034d9f024d 100644
--- a/kernel/sched/pelt.h
+++ b/kernel/sched/pelt.h
@@ -7,6 +7,26 @@ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq);
int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
+#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity);
+
+static inline u64 thermal_load_avg(struct rq *rq)
+{
+ return READ_ONCE(rq->avg_thermal.load_avg);
+}
+#else
+static inline int
+update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+{
+ return 0;
+}
+
+static inline u64 thermal_load_avg(struct rq *rq)
+{
+ return 0;
+}
+#endif
+
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
int update_irq_load_avg(struct rq *rq, u64 running);
#else
@@ -159,6 +179,17 @@ update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
}
static inline int
+update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+{
+ return 0;
+}
+
+static inline u64 thermal_load_avg(struct rq *rq)
+{
+ return 0;
+}
+
+static inline int
update_irq_load_avg(struct rq *rq, u64 running)
{
return 0;
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 028520702717..8f45cdb6463b 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -225,7 +225,7 @@ static bool test_state(unsigned int *tasks, enum psi_states state)
case PSI_MEM_FULL:
return tasks[NR_MEMSTALL] && !tasks[NR_RUNNING];
case PSI_CPU_SOME:
- return tasks[NR_RUNNING] > 1;
+ return tasks[NR_RUNNING] > tasks[NR_ONCPU];
case PSI_NONIDLE:
return tasks[NR_IOWAIT] || tasks[NR_MEMSTALL] ||
tasks[NR_RUNNING];
@@ -669,13 +669,14 @@ static void record_times(struct psi_group_cpu *groupc, int cpu,
groupc->times[PSI_NONIDLE] += delta;
}
-static u32 psi_group_change(struct psi_group *group, int cpu,
- unsigned int clear, unsigned int set)
+static void psi_group_change(struct psi_group *group, int cpu,
+ unsigned int clear, unsigned int set,
+ bool wake_clock)
{
struct psi_group_cpu *groupc;
+ u32 state_mask = 0;
unsigned int t, m;
enum psi_states s;
- u32 state_mask = 0;
groupc = per_cpu_ptr(group->pcpu, cpu);
@@ -695,10 +696,10 @@ static u32 psi_group_change(struct psi_group *group, int cpu,
if (!(m & (1 << t)))
continue;
if (groupc->tasks[t] == 0 && !psi_bug) {
- printk_deferred(KERN_ERR "psi: task underflow! cpu=%d t=%d tasks=[%u %u %u] clear=%x set=%x\n",
+ printk_deferred(KERN_ERR "psi: task underflow! cpu=%d t=%d tasks=[%u %u %u %u] clear=%x set=%x\n",
cpu, t, groupc->tasks[0],
groupc->tasks[1], groupc->tasks[2],
- clear, set);
+ groupc->tasks[3], clear, set);
psi_bug = 1;
}
groupc->tasks[t]--;
@@ -717,7 +718,11 @@ static u32 psi_group_change(struct psi_group *group, int cpu,
write_seqcount_end(&groupc->seq);
- return state_mask;
+ if (state_mask & group->poll_states)
+ psi_schedule_poll_work(group, 1);
+
+ if (wake_clock && !delayed_work_pending(&group->avgs_work))
+ schedule_delayed_work(&group->avgs_work, PSI_FREQ);
}
static struct psi_group *iterate_groups(struct task_struct *task, void **iter)
@@ -744,27 +749,32 @@ static struct psi_group *iterate_groups(struct task_struct *task, void **iter)
return &psi_system;
}
-void psi_task_change(struct task_struct *task, int clear, int set)
+static void psi_flags_change(struct task_struct *task, int clear, int set)
{
- int cpu = task_cpu(task);
- struct psi_group *group;
- bool wake_clock = true;
- void *iter = NULL;
-
- if (!task->pid)
- return;
-
if (((task->psi_flags & set) ||
(task->psi_flags & clear) != clear) &&
!psi_bug) {
printk_deferred(KERN_ERR "psi: inconsistent task state! task=%d:%s cpu=%d psi_flags=%x clear=%x set=%x\n",
- task->pid, task->comm, cpu,
+ task->pid, task->comm, task_cpu(task),
task->psi_flags, clear, set);
psi_bug = 1;
}
task->psi_flags &= ~clear;
task->psi_flags |= set;
+}
+
+void psi_task_change(struct task_struct *task, int clear, int set)
+{
+ int cpu = task_cpu(task);
+ struct psi_group *group;
+ bool wake_clock = true;
+ void *iter = NULL;
+
+ if (!task->pid)
+ return;
+
+ psi_flags_change(task, clear, set);
/*
* Periodic aggregation shuts off if there is a period of no
@@ -777,14 +787,51 @@ void psi_task_change(struct task_struct *task, int clear, int set)
wq_worker_last_func(task) == psi_avgs_work))
wake_clock = false;
- while ((group = iterate_groups(task, &iter))) {
- u32 state_mask = psi_group_change(group, cpu, clear, set);
+ while ((group = iterate_groups(task, &iter)))
+ psi_group_change(group, cpu, clear, set, wake_clock);
+}
+
+void psi_task_switch(struct task_struct *prev, struct task_struct *next,
+ bool sleep)
+{
+ struct psi_group *group, *common = NULL;
+ int cpu = task_cpu(prev);
+ void *iter;
+
+ if (next->pid) {
+ psi_flags_change(next, 0, TSK_ONCPU);
+ /*
+ * When moving state between tasks, the group that
+ * contains them both does not change: we can stop
+ * updating the tree once we reach the first common
+ * ancestor. Iterate @next's ancestors until we
+ * encounter @prev's state.
+ */
+ iter = NULL;
+ while ((group = iterate_groups(next, &iter))) {
+ if (per_cpu_ptr(group->pcpu, cpu)->tasks[NR_ONCPU]) {
+ common = group;
+ break;
+ }
+
+ psi_group_change(group, cpu, 0, TSK_ONCPU, true);
+ }
+ }
+
+ /*
+ * If this is a voluntary sleep, dequeue will have taken care
+ * of the outgoing TSK_ONCPU alongside TSK_RUNNING already. We
+ * only need to deal with it during preemption.
+ */
+ if (sleep)
+ return;
- if (state_mask & group->poll_states)
- psi_schedule_poll_work(group, 1);
+ if (prev->pid) {
+ psi_flags_change(prev, TSK_ONCPU, 0);
- if (wake_clock && !delayed_work_pending(&group->avgs_work))
- schedule_delayed_work(&group->avgs_work, PSI_FREQ);
+ iter = NULL;
+ while ((group = iterate_groups(prev, &iter)) && group != common)
+ psi_group_change(group, cpu, TSK_ONCPU, 0, true);
}
}
@@ -818,17 +865,17 @@ void psi_memstall_enter(unsigned long *flags)
if (static_branch_likely(&psi_disabled))
return;
- *flags = current->flags & PF_MEMSTALL;
+ *flags = current->in_memstall;
if (*flags)
return;
/*
- * PF_MEMSTALL setting & accounting needs to be atomic wrt
+ * in_memstall setting & accounting needs to be atomic wrt
* changes to the task's scheduling state, otherwise we can
* race with CPU migration.
*/
rq = this_rq_lock_irq(&rf);
- current->flags |= PF_MEMSTALL;
+ current->in_memstall = 1;
psi_task_change(current, 0, TSK_MEMSTALL);
rq_unlock_irq(rq, &rf);
@@ -851,13 +898,13 @@ void psi_memstall_leave(unsigned long *flags)
if (*flags)
return;
/*
- * PF_MEMSTALL clearing & accounting needs to be atomic wrt
+ * in_memstall clearing & accounting needs to be atomic wrt
* changes to the task's scheduling state, otherwise we could
* race with CPU migration.
*/
rq = this_rq_lock_irq(&rf);
- current->flags &= ~PF_MEMSTALL;
+ current->in_memstall = 0;
psi_task_change(current, TSK_MEMSTALL, 0);
rq_unlock_irq(rq, &rf);
@@ -916,12 +963,14 @@ void cgroup_move_task(struct task_struct *task, struct css_set *to)
rq = task_rq_lock(task, &rf);
- if (task_on_rq_queued(task))
+ if (task_on_rq_queued(task)) {
task_flags = TSK_RUNNING;
- else if (task->in_iowait)
+ if (task_current(rq, task))
+ task_flags |= TSK_ONCPU;
+ } else if (task->in_iowait)
task_flags = TSK_IOWAIT;
- if (task->flags & PF_MEMSTALL)
+ if (task->in_memstall)
task_flags |= TSK_MEMSTALL;
if (task_flags)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 4043abe45459..df11d88c9895 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1475,6 +1475,13 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags)
int target = find_lowest_rq(p);
/*
+ * Bail out if we were forcing a migration to find a better
+ * fitting CPU but our search failed.
+ */
+ if (!test && target != -1 && !rt_task_fits_capacity(p, target))
+ goto out_unlock;
+
+ /*
* Don't bother moving it if the destination CPU is
* not running a lower priority task.
*/
@@ -1482,6 +1489,8 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags)
p->prio < cpu_rq(target)->rt.highest_prio.curr)
cpu = target;
}
+
+out_unlock:
rcu_read_unlock();
out:
@@ -1495,7 +1504,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
* let's hope p can move out.
*/
if (rq->curr->nr_cpus_allowed == 1 ||
- !cpupri_find(&rq->rd->cpupri, rq->curr, NULL, NULL))
+ !cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
return;
/*
@@ -1503,7 +1512,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
* see if it is pushed or pulled somewhere else.
*/
if (p->nr_cpus_allowed != 1 &&
- cpupri_find(&rq->rd->cpupri, p, NULL, NULL))
+ cpupri_find(&rq->rd->cpupri, p, NULL))
return;
/*
@@ -1647,8 +1656,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
{
if (!task_running(rq, p) &&
- cpumask_test_cpu(cpu, p->cpus_ptr) &&
- rt_task_fits_capacity(p, cpu))
+ cpumask_test_cpu(cpu, p->cpus_ptr))
return 1;
return 0;
@@ -1682,6 +1690,7 @@ static int find_lowest_rq(struct task_struct *task)
struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
+ int ret;
/* Make sure the mask is initialized first */
if (unlikely(!lowest_mask))
@@ -1690,8 +1699,22 @@ static int find_lowest_rq(struct task_struct *task)
if (task->nr_cpus_allowed == 1)
return -1; /* No other targets possible */
- if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask,
- rt_task_fits_capacity))
+ /*
+ * If we're on asym system ensure we consider the different capacities
+ * of the CPUs when searching for the lowest_mask.
+ */
+ if (static_branch_unlikely(&sched_asym_cpucapacity)) {
+
+ ret = cpupri_find_fitness(&task_rq(task)->rd->cpupri,
+ task, lowest_mask,
+ rt_task_fits_capacity);
+ } else {
+
+ ret = cpupri_find(&task_rq(task)->rd->cpupri,
+ task, lowest_mask);
+ }
+
+ if (!ret)
return -1; /* No targets found */
/*
@@ -2202,7 +2225,7 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p)
(rq->curr->nr_cpus_allowed < 2 ||
rq->curr->prio <= p->prio);
- if (need_to_push || !rt_task_fits_capacity(p, cpu_of(rq)))
+ if (need_to_push)
push_rt_tasks(rq);
}
@@ -2274,10 +2297,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
*/
if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
- bool need_to_push = rq->rt.overloaded ||
- !rt_task_fits_capacity(p, cpu_of(rq));
-
- if (p->nr_cpus_allowed > 1 && need_to_push)
+ if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
rt_queue_push_tasks(rq);
#endif /* CONFIG_SMP */
if (p->prio < rq->curr->prio && cpu_online(cpu_of(rq)))
@@ -2449,10 +2469,11 @@ const struct sched_class rt_sched_class = {
*/
static DEFINE_MUTEX(rt_constraints_mutex);
-/* Must be called with tasklist_lock held */
static inline int tg_has_rt_tasks(struct task_group *tg)
{
- struct task_struct *g, *p;
+ struct task_struct *task;
+ struct css_task_iter it;
+ int ret = 0;
/*
* Autogroups do not have RT tasks; see autogroup_create().
@@ -2460,12 +2481,12 @@ static inline int tg_has_rt_tasks(struct task_group *tg)
if (task_group_is_autogroup(tg))
return 0;
- for_each_process_thread(g, p) {
- if (rt_task(p) && task_group(p) == tg)
- return 1;
- }
+ css_task_iter_start(&tg->css, 0, &it);
+ while (!ret && (task = css_task_iter_next(&it)))
+ ret |= rt_task(task);
+ css_task_iter_end(&it);
- return 0;
+ return ret;
}
struct rt_schedulable_data {
@@ -2496,9 +2517,10 @@ static int tg_rt_schedulable(struct task_group *tg, void *data)
return -EINVAL;
/*
- * Ensure we don't starve existing RT tasks.
+ * Ensure we don't starve existing RT tasks if runtime turns zero.
*/
- if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
+ if (rt_bandwidth_enabled() && !runtime &&
+ tg->rt_bandwidth.rt_runtime && tg_has_rt_tasks(tg))
return -EBUSY;
total = to_ratio(period, runtime);
@@ -2564,7 +2586,6 @@ static int tg_set_rt_bandwidth(struct task_group *tg,
return -EINVAL;
mutex_lock(&rt_constraints_mutex);
- read_lock(&tasklist_lock);
err = __rt_schedulable(tg, rt_period, rt_runtime);
if (err)
goto unlock;
@@ -2582,7 +2603,6 @@ static int tg_set_rt_bandwidth(struct task_group *tg,
}
raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
unlock:
- read_unlock(&tasklist_lock);
mutex_unlock(&rt_constraints_mutex);
return err;
@@ -2641,9 +2661,7 @@ static int sched_rt_global_constraints(void)
int ret = 0;
mutex_lock(&rt_constraints_mutex);
- read_lock(&tasklist_lock);
ret = __rt_schedulable(NULL, 0, 0);
- read_unlock(&tasklist_lock);
mutex_unlock(&rt_constraints_mutex);
return ret;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index fdc77e796324..464742874be3 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -118,7 +118,13 @@ extern long calc_load_fold_active(struct rq *this_rq, long adjust);
#ifdef CONFIG_64BIT
# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
-# define scale_load_down(w) ((w) >> SCHED_FIXEDPOINT_SHIFT)
+# define scale_load_down(w) \
+({ \
+ unsigned long __w = (w); \
+ if (__w) \
+ __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \
+ __w; \
+})
#else
# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
# define scale_load(w) (w)
@@ -305,7 +311,6 @@ bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
}
-extern void dl_change_utilization(struct task_struct *p, u64 new_bw);
extern void init_dl_bw(struct dl_bw *dl_b);
extern int sched_dl_global_validate(void);
extern void sched_dl_do_global(void);
@@ -489,7 +494,6 @@ struct cfs_bandwidth { };
/* CFS-related fields in a runqueue */
struct cfs_rq {
struct load_weight load;
- unsigned long runnable_weight;
unsigned int nr_running;
unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */
unsigned int idle_h_nr_running; /* SCHED_IDLE */
@@ -528,7 +532,7 @@ struct cfs_rq {
int nr;
unsigned long load_avg;
unsigned long util_avg;
- unsigned long runnable_sum;
+ unsigned long runnable_avg;
} removed;
#ifdef CONFIG_FAIR_GROUP_SCHED
@@ -688,8 +692,30 @@ struct dl_rq {
#ifdef CONFIG_FAIR_GROUP_SCHED
/* An entity is a task if it doesn't "own" a runqueue */
#define entity_is_task(se) (!se->my_q)
+
+static inline void se_update_runnable(struct sched_entity *se)
+{
+ if (!entity_is_task(se))
+ se->runnable_weight = se->my_q->h_nr_running;
+}
+
+static inline long se_runnable(struct sched_entity *se)
+{
+ if (entity_is_task(se))
+ return !!se->on_rq;
+ else
+ return se->runnable_weight;
+}
+
#else
#define entity_is_task(se) 1
+
+static inline void se_update_runnable(struct sched_entity *se) {}
+
+static inline long se_runnable(struct sched_entity *se)
+{
+ return !!se->on_rq;
+}
#endif
#ifdef CONFIG_SMP
@@ -701,10 +727,6 @@ static inline long se_weight(struct sched_entity *se)
return scale_load_down(se->load.weight);
}
-static inline long se_runnable(struct sched_entity *se)
-{
- return scale_load_down(se->runnable_weight);
-}
static inline bool sched_asym_prefer(int a, int b)
{
@@ -944,6 +966,9 @@ struct rq {
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
struct sched_avg avg_irq;
#endif
+#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+ struct sched_avg avg_thermal;
+#endif
u64 idle_stamp;
u64 avg_idle;
@@ -1107,6 +1132,24 @@ static inline u64 rq_clock_task(struct rq *rq)
return rq->clock_task;
}
+/**
+ * By default the decay is the default pelt decay period.
+ * The decay shift can change the decay period in
+ * multiples of 32.
+ * Decay shift Decay period(ms)
+ * 0 32
+ * 1 64
+ * 2 128
+ * 3 256
+ * 4 512
+ */
+extern int sched_thermal_decay_shift;
+
+static inline u64 rq_clock_thermal(struct rq *rq)
+{
+ return rq_clock_task(rq) >> sched_thermal_decay_shift;
+}
+
static inline void rq_clock_skip_update(struct rq *rq)
{
lockdep_assert_held(&rq->lock);
@@ -1337,8 +1380,6 @@ extern void sched_ttwu_pending(void);
for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
__sd; __sd = __sd->parent)
-#define for_each_lower_domain(sd) for (; sd; sd = sd->child)
-
/**
* highest_flag_domain - Return highest sched_domain containing flag.
* @cpu: The CPU whose highest level of sched domain is to
@@ -1869,7 +1910,6 @@ extern struct dl_bandwidth def_dl_bandwidth;
extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
-extern void init_dl_rq_bw_ratio(struct dl_rq *dl_rq);
#define BW_SHIFT 20
#define BW_UNIT (1 << BW_SHIFT)
@@ -1968,6 +2008,13 @@ static inline int hrtick_enabled(struct rq *rq)
#endif /* CONFIG_SCHED_HRTICK */
+#ifndef arch_scale_freq_tick
+static __always_inline
+void arch_scale_freq_tick(void)
+{
+}
+#endif
+
#ifndef arch_scale_freq_capacity
static __always_inline
unsigned long arch_scale_freq_capacity(int cpu)
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index ba683fe81a6e..33d0daf83842 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -70,7 +70,7 @@ static inline void psi_enqueue(struct task_struct *p, bool wakeup)
return;
if (!wakeup || p->sched_psi_wake_requeue) {
- if (p->flags & PF_MEMSTALL)
+ if (p->in_memstall)
set |= TSK_MEMSTALL;
if (p->sched_psi_wake_requeue)
p->sched_psi_wake_requeue = 0;
@@ -90,9 +90,17 @@ static inline void psi_dequeue(struct task_struct *p, bool sleep)
return;
if (!sleep) {
- if (p->flags & PF_MEMSTALL)
+ if (p->in_memstall)
clear |= TSK_MEMSTALL;
} else {
+ /*
+ * When a task sleeps, schedule() dequeues it before
+ * switching to the next one. Merge the clearing of
+ * TSK_RUNNING and TSK_ONCPU to save an unnecessary
+ * psi_task_change() call in psi_sched_switch().
+ */
+ clear |= TSK_ONCPU;
+
if (p->in_iowait)
set |= TSK_IOWAIT;
}
@@ -109,14 +117,14 @@ static inline void psi_ttwu_dequeue(struct task_struct *p)
* deregister its sleep-persistent psi states from the old
* queue, and let psi_enqueue() know it has to requeue.
*/
- if (unlikely(p->in_iowait || (p->flags & PF_MEMSTALL))) {
+ if (unlikely(p->in_iowait || p->in_memstall)) {
struct rq_flags rf;
struct rq *rq;
int clear = 0;
if (p->in_iowait)
clear |= TSK_IOWAIT;
- if (p->flags & PF_MEMSTALL)
+ if (p->in_memstall)
clear |= TSK_MEMSTALL;
rq = __task_rq_lock(p, &rf);
@@ -126,18 +134,31 @@ static inline void psi_ttwu_dequeue(struct task_struct *p)
}
}
+static inline void psi_sched_switch(struct task_struct *prev,
+ struct task_struct *next,
+ bool sleep)
+{
+ if (static_branch_likely(&psi_disabled))
+ return;
+
+ psi_task_switch(prev, next, sleep);
+}
+
static inline void psi_task_tick(struct rq *rq)
{
if (static_branch_likely(&psi_disabled))
return;
- if (unlikely(rq->curr->flags & PF_MEMSTALL))
+ if (unlikely(rq->curr->in_memstall))
psi_memstall_tick(rq->curr, cpu_of(rq));
}
#else /* CONFIG_PSI */
static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
static inline void psi_ttwu_dequeue(struct task_struct *p) {}
+static inline void psi_sched_switch(struct task_struct *prev,
+ struct task_struct *next,
+ bool sleep) {}
static inline void psi_task_tick(struct rq *rq) {}
#endif /* CONFIG_PSI */
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index dfb64c08a407..8344757bba6e 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -317,8 +317,9 @@ static void sched_energy_set(bool has_eas)
* EAS can be used on a root domain if it meets all the following conditions:
* 1. an Energy Model (EM) is available;
* 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
- * 3. the EM complexity is low enough to keep scheduling overheads low;
- * 4. schedutil is driving the frequency of all CPUs of the rd;
+ * 3. no SMT is detected.
+ * 4. the EM complexity is low enough to keep scheduling overheads low;
+ * 5. schedutil is driving the frequency of all CPUs of the rd;
*
* The complexity of the Energy Model is defined as:
*
@@ -360,6 +361,13 @@ static bool build_perf_domains(const struct cpumask *cpu_map)
goto free;
}
+ /* EAS definitely does *not* handle SMT */
+ if (sched_smt_active()) {
+ pr_warn("rd %*pbl: Disabling EAS, SMT is not supported\n",
+ cpumask_pr_args(cpu_map));
+ goto free;
+ }
+
for_each_cpu(i, cpu_map) {
/* Skip already covered CPUs. */
if (find_pd(pd, i))
@@ -1374,18 +1382,9 @@ sd_init(struct sched_domain_topology_level *tl,
* Convert topological properties into behaviour.
*/
- if (sd->flags & SD_ASYM_CPUCAPACITY) {
- struct sched_domain *t = sd;
-
- /*
- * Don't attempt to spread across CPUs of different capacities.
- */
- if (sd->child)
- sd->child->flags &= ~SD_PREFER_SIBLING;
-
- for_each_lower_domain(t)
- t->flags |= SD_BALANCE_WAKE;
- }
+ /* Don't attempt to spread across CPUs of different capacities. */
+ if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child)
+ sd->child->flags &= ~SD_PREFER_SIBLING;
if (sd->flags & SD_SHARE_CPUCAPACITY) {
sd->imbalance_pct = 110;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 05:50:34 +0000