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| author | Quentin Perret <qperret@google.com> | 2020-04-16 10:59:56 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-04-22 23:10:13 +0200 |
| commit | eaf5a92ebde5bca3bb2565616115bd6d579486cd (patch) | |
| tree | 2aeb36e9b491ab5f5ad9049c5abf2b7d123dab1e /kernel | |
| parent | x86, sched: Move check for CPU type to caller function (diff) | |
| download | linux-eaf5a92ebde5bca3bb2565616115bd6d579486cd.tar.xz linux-eaf5a92ebde5bca3bb2565616115bd6d579486cd.zip | |
sched/core: Fix reset-on-fork from RT with uclamp
uclamp_fork() resets the uclamp values to their default when the
reset-on-fork flag is set. It also checks whether the task has a RT
policy, and sets its uclamp.min to 1024 accordingly. However, during
reset-on-fork, the task's policy is lowered to SCHED_NORMAL right after,
hence leading to an erroneous uclamp.min setting for the new task if it
was forked from RT.
Fix this by removing the unnecessary check on rt_task() in
uclamp_fork() as this doesn't make sense if the reset-on-fork flag is
set.
Fixes: 1a00d999971c ("sched/uclamp: Set default clamps for RT tasks")
Reported-by: Chitti Babu Theegala <ctheegal@codeaurora.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Patrick Bellasi <patrick.bellasi@matbug.net>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lkml.kernel.org/r/20200416085956.217587-1-qperret@google.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3a61a3b8eaa9..9a2fbf98fd6f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1232,13 +1232,8 @@ static void uclamp_fork(struct task_struct *p) return; for_each_clamp_id(clamp_id) { - unsigned int clamp_value = uclamp_none(clamp_id); - - /* By default, RT tasks always get 100% boost */ - if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN)) - clamp_value = uclamp_none(UCLAMP_MAX); - - uclamp_se_set(&p->uclamp_req[clamp_id], clamp_value, false); + uclamp_se_set(&p->uclamp_req[clamp_id], + uclamp_none(clamp_id), false); } } |