From b377c2a089d4538e6e62e51fa595c896c314d83d Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 30 Jun 2015 03:29:48 +0200 Subject: [PATCH] stop_machine: Don't do for_each_cpu() twice in queue_stop_cpus_work() queue_stop_cpus_work() can do everything in one for_each_cpu() loop. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Tejun Heo Cc: Thomas Gleixner Cc: dave@stgolabs.net Cc: der.herr@hofr.at Cc: paulmck@linux.vnet.ibm.com Cc: riel@redhat.com Cc: viro@ZenIV.linux.org.uk Link: http://lkml.kernel.org/r/20150630012948.GA23927@redhat.com Signed-off-by: Ingo Molnar --- kernel/stop_machine.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 6e677b003164..621220852df0 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -303,22 +303,19 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask, struct cpu_stop_work *work; unsigned int cpu; - /* initialize works and done */ - for_each_cpu(cpu, cpumask) { - work = &per_cpu(cpu_stopper.stop_work, cpu); - work->fn = fn; - work->arg = arg; - work->done = done; - } - /* * Disable preemption while queueing to avoid getting * preempted by a stopper which might wait for other stoppers * to enter @fn which can lead to deadlock. */ lg_global_lock(&stop_cpus_lock); - for_each_cpu(cpu, cpumask) - cpu_stop_queue_work(cpu, &per_cpu(cpu_stopper.stop_work, cpu)); + for_each_cpu(cpu, cpumask) { + work = &per_cpu(cpu_stopper.stop_work, cpu); + work->fn = fn; + work->arg = arg; + work->done = done; + cpu_stop_queue_work(cpu, work); + } lg_global_unlock(&stop_cpus_lock); }