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authorOleg Nesterov <oleg@redhat.com>2015-10-08 17:51:34 +0300
committerIngo Molnar <mingo@kernel.org>2015-10-20 11:23:54 +0300
commit5caa1c089aebcb83ccd5b79a3b88b0aa58288d05 (patch)
treefefeab98c46182094502ae2642fd8a599bb5ec0d /kernel/stop_machine.c
parent233e7f267e580fefdeb36628b7efe8bfe056d27c (diff)
downloadlinux-5caa1c089aebcb83ccd5b79a3b88b0aa58288d05.tar.xz
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: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/stop_machine.c')
-rw-r--r--kernel/stop_machine.c37
1 files changed, 26 insertions, 11 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 6a402098d4ab..688d6b37bb59 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -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();