Qais Yousef 315c4f8848 sched/uclamp: Fix rq->uclamp_max not set on first enqueue ... Commit d81ae8aac8 ("sched/uclamp: Fix initialization of struct uclamp_rq") introduced a bug where uclamp_max of the rq is not reset to match the woken up task's uclamp_max when the rq is idle. The code was relying on rq->uclamp_max initialized to zero, so on first enqueue static inline void uclamp_rq_inc_id(struct rq *rq, struct task_struct *p, enum uclamp_id clamp_id) { ... if (uc_se->value > READ_ONCE(uc_rq->value)) WRITE_ONCE(uc_rq->value, uc_se->value); } was actually resetting it. But since commit d81ae8aac8 changed the default to 1024, this no longer works. And since rq->uclamp_flags is also initialized to 0, neither above code path nor uclamp_idle_reset() update the rq->uclamp_max on first wake up from idle. This is only visible from first wake up(s) until the first dequeue to idle after enabling the static key. And it only matters if the uclamp_max of this task is < 1024 since only then its uclamp_max will be effectively ignored. Fix it by properly initializing rq->uclamp_flags = UCLAMP_FLAG_IDLE to ensure uclamp_idle_reset() is called which then will update the rq uclamp_max value as expected. Fixes: d81ae8aac8 ("sched/uclamp: Fix initialization of struct uclamp_rq") Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lkml.kernel.org/r/20211202112033.1705279-1-qais.yousef@arm.com		2021-12-04 10:56:18 +01:00
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autogroup.c	sched/fair: Prevent dead task groups from regaining cfs_rq's	2021-11-11 13:09:33 +01:00
autogroup.h
clock.c
completion.c
core.c	sched/uclamp: Fix rq->uclamp_max not set on first enqueue	2021-12-04 10:56:18 +01:00
core_sched.c	kernel.sys.v5.16	2021-11-10 16:10:47 -08:00
cpuacct.c
cpudeadline.c
cpudeadline.h
cpufreq.c
cpufreq_schedutil.c	cpufreq: schedutil: Use kobject release() method to free sugov_tunables	2021-08-06 15:34:55 +02:00
cpupri.c
cpupri.h
cputime.c	sched/cputime: Fix getrusage(RUSAGE_THREAD) with nohz_full	2021-12-02 15:08:22 +01:00
deadline.c	sched/dl: Support schedstats for deadline sched class	2021-10-05 15:51:53 +02:00
debug.c	sched: Fix DEBUG && !SCHEDSTATS warn	2021-10-06 10:30:57 +02:00
fair.c	sched/fair: Prevent dead task groups from regaining cfs_rq's	2021-11-11 13:09:33 +01:00
features.h	sched: Disable TTWU_QUEUE on RT	2021-10-05 15:52:12 +02:00
idle.c	sched/idle: Make the idle timer expire in hard interrupt context	2021-09-09 10:36:16 +02:00
isolation.c
loadavg.c
Makefile	sched: Disable -Wunused-but-set-variable	2021-10-15 11:25:15 +02:00
membarrier.c
pelt.c
pelt.h
psi.c
rt.c	sched/fair: Prevent dead task groups from regaining cfs_rq's	2021-11-11 13:09:33 +01:00
sched-pelt.h
sched.h	sched/fair: Prevent dead task groups from regaining cfs_rq's	2021-11-11 13:09:33 +01:00
smp.h
stats.c	sched: Introduce task block time in schedstats	2021-10-05 15:51:48 +02:00
stats.h	sched: Make schedstats helpers independent of fair sched class	2021-10-05 15:51:47 +02:00
stop_task.c	sched: Make struct sched_statistics independent of fair sched class	2021-10-05 15:51:45 +02:00
swait.c
topology.c	Merge branch 'akpm' (patches from Andrew)	2021-11-06 14:08:17 -07:00
wait.c
wait_bit.c