Commit 184af1cd authored Aug 25, 2014 by Srivatsa Vaddagiri Committed by Matt Wagantall May 30, 2015

sched: Initialize env->loop variable to 0

load_balance() function does not explicitly initialize env->loop
variable to 0. As a result, there is a vague possibility of
move_tasks() hitting a very long (unnecessary) loop when its unable to
move tasks from src_cpu. This can lead to unpleasant results like a
watchdog bark. Fix this by explicitly initializing env->loop variable
to 0 (in both load_balance() and active_load_balance_cpu_stop()).

Change-Id: I36b84c91a9753870fa16ef9c9339db7b706527be
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>

parent 1c3183ee

kernel/sched/fair.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -7936,6 +7936,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
		.tasks = LIST_HEAD_INIT(env.tasks),
		.imbalance = 0,
		.flags = 0,
		.loop = 0,
		};

		/*
		@@ -8388,6 +8389,7 @@ static int active_load_balance_cpu_stop(void *data)
		.src_rq = busiest_rq,
		.idle = CPU_IDLE,
		.flags = 0,
		.loop = 0,
		};

		raw_spin_lock_irq(&busiest_rq->lock);