Do not call dequeue_pushable_task() when failing to push an eligible
task, as it remains pushable, merely not at this particular moment.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Mike Galbraith <mgalbraith@gmx.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Yong Zhang <yong.zhang0@gmail.com>
Link: http://lkml.kernel.org/r/1306895385.4791.26.camel@marge.simson.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
{
struct task_struct *next_task;
struct rq *lowest_rq;
{
struct task_struct *next_task;
struct rq *lowest_rq;
if (!rq->rt.overloaded)
return 0;
if (!rq->rt.overloaded)
return 0;
if (!lowest_rq) {
struct task_struct *task;
/*
if (!lowest_rq) {
struct task_struct *task;
/*
- * find lock_lowest_rq releases rq->lock
+ * find_lock_lowest_rq releases rq->lock
* so it is possible that next_task has migrated.
*
* We need to make sure that the task is still on the same
* so it is possible that next_task has migrated.
*
* We need to make sure that the task is still on the same
task = pick_next_pushable_task(rq);
if (task_cpu(next_task) == rq->cpu && task == next_task) {
/*
task = pick_next_pushable_task(rq);
if (task_cpu(next_task) == rq->cpu && task == next_task) {
/*
- * If we get here, the task hasn't moved at all, but
- * it has failed to push. We will not try again,
- * since the other cpus will pull from us when they
- * are ready.
+ * The task hasn't migrated, and is still the next
+ * eligible task, but we failed to find a run-queue
+ * to push it to. Do not retry in this case, since
+ * other cpus will pull from us when ready.
- dequeue_pushable_task(rq, next_task);
deactivate_task(rq, next_task, 0);
set_task_cpu(next_task, lowest_rq->cpu);
activate_task(lowest_rq, next_task, 0);
deactivate_task(rq, next_task, 0);
set_task_cpu(next_task, lowest_rq->cpu);
activate_task(lowest_rq, next_task, 0);
resched_task(lowest_rq->curr);
resched_task(lowest_rq->curr);
out:
put_task_struct(next_task);
out:
put_task_struct(next_task);
}
static void push_rt_tasks(struct rq *rq)
}
static void push_rt_tasks(struct rq *rq)