From b2454caa8977ade27292a71f2def5e403e24b4d5 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Mar 2016 12:54:14 +0100 Subject: 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) Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160310120025.169219710@linutronix.de Signed-off-by: Thomas Gleixner --- kernel/cpu.c | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'kernel/cpu.c') diff --git a/kernel/cpu.c b/kernel/cpu.c index 15402b72fbc7..c134a35374a1 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -703,21 +703,6 @@ static int takedown_cpu(unsigned int cpu) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int err; - /* - * By now 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(); - /* Park the smpboot threads */ kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); smpboot_park_threads(cpu); -- cgit v1.2.3