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| author | Dietmar Eggemann <dietmar.eggemann@arm.com> | 2018-08-03 15:05:38 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-10-02 09:45:03 +0200 |
| commit | 4a465e3ebbc8004ce4f7f08f6022ee8315a94edf (patch) | |
| tree | 74b34e40dd3b727fbf9f02de7e3288227e764074 /kernel/sched | |
| parent | fdf5f315d5cfaefb7bb8a62ec4bf37b9891837aa (diff) | |
| download | linux-4a465e3ebbc8004ce4f7f08f6022ee8315a94edf.tar.bz2 | |
sched/fair: Remove setting task's se->runnable_weight during PELT update
A CFS (SCHED_OTHER, SCHED_BATCH or SCHED_IDLE policy) task's
se->runnable_weight must always be in sync with its se->load.weight.
se->runnable_weight is set to se->load.weight when the task is
forked (init_entity_runnable_average()) or reniced (reweight_entity()).
There are two cases in set_load_weight() which since they currently only
set se->load.weight could lead to a situation in which se->load.weight
is different to se->runnable_weight for a CFS task:
(1) A task switches to SCHED_IDLE.
(2) A SCHED_FIFO, SCHED_RR or SCHED_DEADLINE task which has been reniced
(during which only its static priority gets set) switches to
SCHED_OTHER or SCHED_BATCH.
Set se->runnable_weight to se->load.weight in these two cases to prevent
this. This eliminates the need to explicitly set it to se->load.weight
during PELT updates in the CFS scheduler fastpath.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: http://lkml.kernel.org/r/20180803140538.1178-1-dietmar.eggemann@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 2 | ||||
| -rw-r--r-- | kernel/sched/pelt.c | 6 |
2 files changed, 2 insertions, 6 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f2caf1bae4a3..56b3c1781276 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -700,6 +700,7 @@ static void set_load_weight(struct task_struct *p, bool update_load) if (idle_policy(p->policy)) { load->weight = scale_load(WEIGHT_IDLEPRIO); load->inv_weight = WMULT_IDLEPRIO; + p->se.runnable_weight = load->weight; return; } @@ -712,6 +713,7 @@ 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; } } diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c index 48a126486435..90fb5bc12ad4 100644 --- a/kernel/sched/pelt.c +++ b/kernel/sched/pelt.c @@ -269,9 +269,6 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runna int __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se) { - if (entity_is_task(se)) - se->runnable_weight = se->load.weight; - if (___update_load_sum(now, cpu, &se->avg, 0, 0, 0)) { ___update_load_avg(&se->avg, se_weight(se), se_runnable(se)); return 1; @@ -282,9 +279,6 @@ int __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se) int __update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se) { - if (entity_is_task(se)) - se->runnable_weight = se->load.weight; - if (___update_load_sum(now, cpu, &se->avg, !!se->on_rq, !!se->on_rq, cfs_rq->curr == se)) { |