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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-13 12:22:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-13 12:22:32 -0700 |
| commit | ec846ecd6350857a8b8b9a6b78c763d45e0f09b8 (patch) | |
| tree | 44896da8501c42f2c41b7fc17975dc7fe16b2789 /kernel/sched/fair.c | |
| parent | b5df1b3a5637deae352d282b50d4b99d0e2b8d1d (diff) | |
| parent | 9469eb01db891b55367ee7539f1b9f7f6fd2819d (diff) | |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Three CPU hotplug related fixes and a debugging improvement"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/debug: Add debugfs knob for "sched_debug"
sched/core: WARN() when migrating to an offline CPU
sched/fair: Plug hole between hotplug and active_load_balance()
sched/fair: Avoid newidle balance for !active CPUs
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0a85641e62ce..70ba32e08a23 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8437,6 +8437,12 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf) this_rq->idle_stamp = rq_clock(this_rq); /* + * Do not pull tasks towards !active CPUs... + */ + if (!cpu_active(this_cpu)) + return 0; + + /* * This is OK, because current is on_cpu, which avoids it being picked * for load-balance and preemption/IRQs are still disabled avoiding * further scheduler activity on it and we're being very careful to @@ -8543,6 +8549,13 @@ static int active_load_balance_cpu_stop(void *data) struct rq_flags rf; rq_lock_irq(busiest_rq, &rf); + /* + * Between queueing the stop-work and running it is a hole in which + * CPUs can become inactive. We should not move tasks from or to + * inactive CPUs. + */ + if (!cpu_active(busiest_cpu) || !cpu_active(target_cpu)) + goto out_unlock; /* make sure the requested cpu hasn't gone down in the meantime */ if (unlikely(busiest_cpu != smp_processor_id() || |