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| author | Qais Yousef <qais.yousef@arm.com> | 2020-06-30 12:21:22 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-19 08:15:55 +0200 |
| commit | 047187eb0a3f5aa233ecd1d01102eeb8fc64a67a (patch) | |
| tree | 617b344c2d52c06b59f142663961fe7ab5669a66 /kernel/sched | |
| parent | 4d7115d29201a1dfa77ac1b7bc3f29606b14b700 (diff) | |
| download | linux-stable-047187eb0a3f5aa233ecd1d01102eeb8fc64a67a.tar.gz linux-stable-047187eb0a3f5aa233ecd1d01102eeb8fc64a67a.tar.bz2 linux-stable-047187eb0a3f5aa233ecd1d01102eeb8fc64a67a.zip | |
sched/uclamp: Fix initialization of struct uclamp_rq
[ Upstream commit d81ae8aac85ca2e307d273f6dc7863a721bf054e ]
struct uclamp_rq was zeroed out entirely in assumption that in the first
call to uclamp_rq_inc() they'd be initialized correctly in accordance to
default settings.
But when next patch introduces a static key to skip
uclamp_rq_{inc,dec}() until userspace opts in to use uclamp, schedutil
will fail to perform any frequency changes because the
rq->uclamp[UCLAMP_MAX].value is zeroed at init and stays as such. Which
means all rqs are capped to 0 by default.
Fix it by making sure we do proper initialization at init without
relying on uclamp_rq_inc() doing it later.
Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting")
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: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lkml.kernel.org/r/20200630112123.12076-2-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 38ae3cf9d173..b34b5c6e2524 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1238,6 +1238,20 @@ static void uclamp_fork(struct task_struct *p) } } +static void __init init_uclamp_rq(struct rq *rq) +{ + enum uclamp_id clamp_id; + struct uclamp_rq *uc_rq = rq->uclamp; + + for_each_clamp_id(clamp_id) { + uc_rq[clamp_id] = (struct uclamp_rq) { + .value = uclamp_none(clamp_id) + }; + } + + rq->uclamp_flags = 0; +} + static void __init init_uclamp(void) { struct uclamp_se uc_max = {}; @@ -1246,11 +1260,8 @@ static void __init init_uclamp(void) mutex_init(&uclamp_mutex); - for_each_possible_cpu(cpu) { - memset(&cpu_rq(cpu)->uclamp, 0, - sizeof(struct uclamp_rq)*UCLAMP_CNT); - cpu_rq(cpu)->uclamp_flags = 0; - } + for_each_possible_cpu(cpu) + init_uclamp_rq(cpu_rq(cpu)); for_each_clamp_id(clamp_id) { uclamp_se_set(&init_task.uclamp_req[clamp_id], |