Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Thomas Gleixner:
 "A single bugfix to prevent a pinned thread which queues stomp machine
  work to be preempted by the stopper thread on its CPU which causes a
  live lock as it is unable to wake the second CPUs stopper thread"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine: Atomically queue and wake stopper threads
This commit is contained in:
Linus Torvalds 2018-08-13 11:21:34 -07:00
commit 2406fb8d94

View File

@ -81,6 +81,7 @@ static bool cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
unsigned long flags;
bool enabled;
preempt_disable();
raw_spin_lock_irqsave(&stopper->lock, flags);
enabled = stopper->enabled;
if (enabled)
@ -90,6 +91,7 @@ static bool cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
raw_spin_unlock_irqrestore(&stopper->lock, flags);
wake_up_q(&wakeq);
preempt_enable();
return enabled;
}