diff options
| author | Valentin Schneider <valentin.schneider@arm.com> | 2018-07-04 11:17:46 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-09-10 11:05:52 +0200 |
| commit | e90c8fe15a3bf93a23088bcf1a56a0fa391d4e50 (patch) | |
| tree | a04280c786bd43f82cb01576a8d8ff5786bb69a6 /kernel/sched/fair.c | |
| parent | 575638d1047eb057a5cdf95cc0b3c084e1279508 (diff) | |
sched/fair: Wrap rq->rd->overload accesses with READ/WRITE_ONCE()
This variable can be read and set locklessly within update_sd_lb_stats().
As such, READ/WRITE_ONCE() are added to make sure nothing terribly wrong
can happen because of the compiler.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: gaku.inami.xh@renesas.com
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1530699470-29808-9-git-send-email-morten.rasmussen@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 23017939ecab..d9c4e97bfebd 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8058,8 +8058,8 @@ next_group: if (!env->sd->parent) { /* update overload indicator if we are at root domain */ - if (env->dst_rq->rd->overload != overload) - env->dst_rq->rd->overload = overload; + if (READ_ONCE(env->dst_rq->rd->overload) != overload) + WRITE_ONCE(env->dst_rq->rd->overload, overload); } } @@ -9502,7 +9502,7 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf) rq_unpin_lock(this_rq, rf); if (this_rq->avg_idle < sysctl_sched_migration_cost || - !this_rq->rd->overload) { + !READ_ONCE(this_rq->rd->overload)) { rcu_read_lock(); sd = rcu_dereference_check_sched_domain(this_rq->sd); |