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authorDavid S. Miller <davem@davemloft.net>2014-11-01 18:53:27 (GMT)
committerDavid S. Miller <davem@davemloft.net>2014-11-01 18:53:27 (GMT)
commit55b42b5ca2dcf143465968697fe6c6503b05fca1 (patch)
tree91878cd53efc44ba67244d4d3897020828c87c01 /kernel/sched/deadline.c
parent10738eeaf4ab3de092586cefcc082e7d43ca0044 (diff)
parentec1f1276022e4e3ca40871810217d513e39ff250 (diff)
downloadlinux-55b42b5ca2dcf143465968697fe6c6503b05fca1.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/phy/marvell.c Simple overlapping changes in drivers/net/phy/marvell.c Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/sched/deadline.c')
-rw-r--r--kernel/sched/deadline.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 256e577..5285332 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -518,12 +518,20 @@ again:
}
/*
- * We need to take care of a possible races here. In fact, the
- * task might have changed its scheduling policy to something
- * different from SCHED_DEADLINE or changed its reservation
- * parameters (through sched_setattr()).
+ * We need to take care of several possible races here:
+ *
+ * - the task might have changed its scheduling policy
+ * to something different than SCHED_DEADLINE
+ * - the task might have changed its reservation parameters
+ * (through sched_setattr())
+ * - the task might have been boosted by someone else and
+ * might be in the boosting/deboosting path
+ *
+ * In all this cases we bail out, as the task is already
+ * in the runqueue or is going to be enqueued back anyway.
*/
- if (!dl_task(p) || dl_se->dl_new)
+ if (!dl_task(p) || dl_se->dl_new ||
+ dl_se->dl_boosted || !dl_se->dl_throttled)
goto unlock;
sched_clock_tick();
@@ -532,7 +540,7 @@ again:
dl_se->dl_yielded = 0;
if (task_on_rq_queued(p)) {
enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
- if (task_has_dl_policy(rq->curr))
+ if (dl_task(rq->curr))
check_preempt_curr_dl(rq, p, 0);
else
resched_curr(rq);
@@ -847,8 +855,19 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
* smaller than our one... OTW we keep our runtime and
* deadline.
*/
- if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio))
+ if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) {
pi_se = &pi_task->dl;
+ } else if (!dl_prio(p->normal_prio)) {
+ /*
+ * Special case in which we have a !SCHED_DEADLINE task
+ * that is going to be deboosted, but exceedes its
+ * runtime while doing so. No point in replenishing
+ * it, as it's going to return back to its original
+ * scheduling class after this.
+ */
+ BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH);
+ return;
+ }
/*
* If p is throttled, we do nothing. In fact, if it exhausted
@@ -1607,8 +1626,12 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
/* Only reschedule if pushing failed */
check_resched = 0;
#endif /* CONFIG_SMP */
- if (check_resched && task_has_dl_policy(rq->curr))
- check_preempt_curr_dl(rq, p, 0);
+ if (check_resched) {
+ if (dl_task(rq->curr))
+ check_preempt_curr_dl(rq, p, 0);
+ else
+ resched_curr(rq);
+ }
}
}