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Commit 5caa1c08 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Ingo Molnar
Browse files

stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works() 



Preparation to simplify the review of the next change. Add two simple
helpers, __cpu_stop_queue_work() and cpu_stop_queue_two_works() which
simply take a bit of code from their callers.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20151008145134.GA18146@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 233e7f26

kernel/stop_machine.c

+26 −11
Original line number Diff line number Diff line
@@ -73,21 +73,24 @@ static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed) 
	}

}



static void __cpu_stop_queue_work(struct cpu_stopper *stopper,

					struct cpu_stop_work *work)

{

	list_add_tail(&work->list, &stopper->works);

	wake_up_process(stopper->thread);

}



/* queue @work to @stopper.  if offline, @work is completed immediately */

static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)

{

	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);



	unsigned long flags;



	spin_lock_irqsave(&stopper->lock, flags);



	if (stopper->enabled) {

		list_add_tail(&work->list, &stopper->works);

		wake_up_process(stopper->thread);

	} else

	if (stopper->enabled)

		__cpu_stop_queue_work(stopper, work);

	else

		cpu_stop_signal_done(work->done, false);



	spin_unlock_irqrestore(&stopper->lock, flags);

}
@@ -213,6 +216,16 @@ static int multi_cpu_stop(void *data) 
	return err;

}



static int cpu_stop_queue_two_works(int cpu1, struct cpu_stop_work *work1,

				    int cpu2, struct cpu_stop_work *work2)

{

	lg_double_lock(&stop_cpus_lock, cpu1, cpu2);

	cpu_stop_queue_work(cpu1, work1);

	cpu_stop_queue_work(cpu2, work2);

	lg_double_unlock(&stop_cpus_lock, cpu1, cpu2);



	return 0;

}

/**

 * stop_two_cpus - stops two cpus

 * @cpu1: the cpu to stop
@@ -260,10 +273,12 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void * 
		return -ENOENT;

	}



	lg_double_lock(&stop_cpus_lock, cpu1, cpu2);

	cpu_stop_queue_work(cpu1, &work1);

	cpu_stop_queue_work(cpu2, &work2);

	lg_double_unlock(&stop_cpus_lock, cpu1, cpu2);

	if (cpu1 > cpu2)

		swap(cpu1, cpu2);

	if (cpu_stop_queue_two_works(cpu1, &work1, cpu2, &work2)) {

		preempt_enable();

		return -ENOENT;

	}



	preempt_enable();