diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2016-03-10 11:54:14 (GMT) |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-05-06 12:58:24 (GMT) |
| commit | b2454caa8977ade27292a71f2def5e403e24b4d5 (patch) | |
| tree | aead0505616aa4402a99f4a85bf2dc6d001e2a4a /kernel/sched | |
| parent | 40190a78f85fec29f0fdd21f6b4415712085711e (diff) | |
| download | linux-b2454caa8977ade27292a71f2def5e403e24b4d5.tar.xz | |
sched/hotplug: Move sync_rcu to be with set_cpu_active(false)
The sync_rcu stuff is specificically for clearing bits in the active
mask, such that everybody will observe the bit cleared and will not
consider the cleared CPU for load-balancing etc.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160310120025.169219710@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 73bcd93..0a31078 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7112,6 +7112,20 @@ int sched_cpu_deactivate(unsigned int cpu) int ret; set_cpu_active(cpu, false); + /* + * We've cleared cpu_active_mask, wait for all preempt-disabled and RCU + * users of this state to go away such that all new such users will + * observe it. + * + * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might + * not imply sync_sched(), so wait for both. + * + * Do sync before park smpboot threads to take care the rcu boost case. + */ + if (IS_ENABLED(CONFIG_PREEMPT)) + synchronize_rcu_mult(call_rcu, call_rcu_sched); + else + synchronize_rcu(); if (!sched_smp_initialized) return 0; |