stop_machine: Change __stop_cpus() to rely on cpu_stop_queue_work()

Change queue_stop_cpus_work() to return true if it queues at least one
work, this means that the caller should wait.

__stop_cpus() can check the value returned by queue_stop_cpus_work() and
avoid done.executed, just like stop_one_cpu() does.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Milos Vyletel <milos@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20151115193323.GA8262@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Oleg Nesterov 2015-11-15 20:33:23 +01:00 committed by Ingo Molnar
parent 958c5f848e
commit 4aff1ca697
1 changed files with 10 additions and 4 deletions

View File

@ -318,12 +318,13 @@ bool stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
/* static data for stop_cpus */
static DEFINE_MUTEX(stop_cpus_mutex);
static void queue_stop_cpus_work(const struct cpumask *cpumask,
static bool queue_stop_cpus_work(const struct cpumask *cpumask,
cpu_stop_fn_t fn, void *arg,
struct cpu_stop_done *done)
{
struct cpu_stop_work *work;
unsigned int cpu;
bool queued = false;
/*
* Disable preemption while queueing to avoid getting
@ -336,9 +337,12 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask,
work->fn = fn;
work->arg = arg;
work->done = done;
cpu_stop_queue_work(cpu, work);
if (cpu_stop_queue_work(cpu, work))
queued = true;
}
lg_global_unlock(&stop_cpus_lock);
return queued;
}
static int __stop_cpus(const struct cpumask *cpumask,
@ -347,9 +351,11 @@ static int __stop_cpus(const struct cpumask *cpumask,
struct cpu_stop_done done;
cpu_stop_init_done(&done, cpumask_weight(cpumask));
queue_stop_cpus_work(cpumask, fn, arg, &done);
if (!queue_stop_cpus_work(cpumask, fn, arg, &done))
return -ENOENT;
wait_for_completion(&done.completion);
return done.executed ? done.ret : -ENOENT;
WARN_ON(!done.executed);
return done.ret;
}
/**