Commit 6385a475 authored Oct 28, 2016 by Syed Rameez Mustafa

sched/hmp: Disable interrupts when resetting all task stats

Taking the pi_lock without disabling interrupts in reset_all_task_stats()
is problematic. In that an interrupt can end up waking a task which in
turn needs the pi_lock again causing a deadlock. Disable interrupts along
with taking the lock to avoid this problem.

Change-Id: If27cb2bb3fcaafa5c8435f3c2e0e4be9b8f1e987
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>

parent bcd8ec92

kernel/sched/hmp.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -3106,9 +3106,9 @@ static void reset_all_task_stats(void)

		read_lock(&tasklist_lock);
		do_each_thread(g, p) {
		raw_spin_lock(&p->pi_lock);
		raw_spin_lock_irq(&p->pi_lock);
		reset_task_stats(p);
		raw_spin_unlock(&p->pi_lock);
		raw_spin_unlock_irq(&p->pi_lock);
		} while_each_thread(g, p);
		read_unlock(&tasklist_lock);
		}