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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-17 10:49:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-17 10:49:42 -0700 |
| commit | c2ea72fd869145130969d6b07273c479cf2a22f5 (patch) | |
| tree | da226ab4151c20ae259249f8fc301744eeb461c6 /kernel/time | |
| parent | a706797febf4ff60ad61f855a01707be9fc3cf4c (diff) | |
| parent | 5473e0cc37c03c576adbda7591a6cc8e37c1bb7f (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:
"A migrate_tasks() locking fix, and a late-coming nohz change plus a
nohz debug check"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: 'Annotate' migrate_tasks()
nohz: Assert existing housekeepers when nohz full enabled
nohz: Affine unpinned timers to housekeepers
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/tick-sched.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3319e16f31e5..7c7ec4515983 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -290,16 +290,17 @@ static int __init tick_nohz_full_setup(char *str) __setup("nohz_full=", tick_nohz_full_setup); static int tick_nohz_cpu_down_callback(struct notifier_block *nfb, - unsigned long action, - void *hcpu) + unsigned long action, + void *hcpu) { unsigned int cpu = (unsigned long)hcpu; switch (action & ~CPU_TASKS_FROZEN) { case CPU_DOWN_PREPARE: /* - * If we handle the timekeeping duty for full dynticks CPUs, - * we can't safely shutdown that CPU. + * The boot CPU handles housekeeping duty (unbound timers, + * workqueues, timekeeping, ...) on behalf of full dynticks + * CPUs. It must remain online when nohz full is enabled. */ if (tick_nohz_full_running && tick_do_timer_cpu == cpu) return NOTIFY_BAD; @@ -370,6 +371,12 @@ void __init tick_nohz_init(void) cpu_notifier(tick_nohz_cpu_down_callback, 0); pr_info("NO_HZ: Full dynticks CPUs: %*pbl.\n", cpumask_pr_args(tick_nohz_full_mask)); + + /* + * We need at least one CPU to handle housekeeping work such + * as timekeeping, unbound timers, workqueues, ... + */ + WARN_ON_ONCE(cpumask_empty(housekeeping_mask)); } #endif |