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| author |   Quentin Perret <qperret@google.com> | 2021-07-27 11:11:01 +0100 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2021-08-04 15:16:43 +0200 |
| commit | f95091536f78971b269ec321b057b8d630b0ad8a (patch) | |
| tree | 01e85f0272872bfddd009272a2e4ae22e9100683 /kernel/sched/sched.h | |
| parent | sched: remove redundant on_rq status change (diff) | |
| download | linux-dev-f95091536f78971b269ec321b057b8d630b0ad8a.tar.xz linux-dev-f95091536f78971b269ec321b057b8d630b0ad8a.zip | |
sched/deadline: Fix reset_on_fork reporting of DL tasks
It is possible for sched_getattr() to incorrectly report the state of
the reset_on_fork flag when called on a deadline task.
Indeed, if the flag was set on a deadline task using sched_setattr()
with flags (SCHED_FLAG_RESET_ON_FORK | SCHED_FLAG_KEEP_PARAMS), then
p->sched_reset_on_fork will be set, but __setscheduler() will bail out
early, which means that the dl_se->flags will not get updated by
__setscheduler_params()->__setparam_dl(). Consequently, if
sched_getattr() is then called on the task, __getparam_dl() will
override kattr.sched_flags with the now out-of-date copy in dl_se->flags
and report the stale value to userspace.
To fix this, make sure to only copy the flags that are relevant to
sched_deadline to and from the dl_se->flags field.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210727101103.2729607-2-qperret@google.com
Diffstat (limited to '')
| -rw-r--r-- | kernel/sched/sched.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 9a1c6aeb9165..75a5c120e7d9 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -227,6 +227,8 @@ static inline void update_avg(u64 *avg, u64 sample) */ #define SCHED_FLAG_SUGOV 0x10000000 +#define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) + static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se) { #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL |