Commit-ID: a2f5c9ab79f78e8b91ac993e0543d65b661dd19b Gitweb: http://git.kernel.org/tip/a2f5c9ab79f78e8b91ac993e0543d65b661dd19b Author: Darren Hart <dvhart@xxxxxxxxxxxxxxx> AuthorDate: Tue, 22 Feb 2011 13:04:33 -0800 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Fri, 4 Mar 2011 11:14:29 +0100 sched: Allow SCHED_BATCH to preempt SCHED_IDLE tasks Perform the test for SCHED_IDLE before testing for SCHED_BATCH (and ensure idle tasks don't preempt idle tasks) so the non-interactive, but still important, SCHED_BATCH tasks will run in favor of the very low priority SCHED_IDLE tasks. Signed-off-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Acked-by: Mike Galbraith <efault@xxxxxx> Cc: Richard Purdie <richard.purdie@xxxxxxxxxxxxxxxxxxx> LKML-Reference: <1298408674-3130-2-git-send-email-dvhart@xxxxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/sched_fair.c | 12 +++++++----- 1 files changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 3a88dee..1438e13 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1870,16 +1870,18 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ if (test_tsk_need_resched(curr)) return; + /* Idle tasks are by definition preempted by non-idle tasks. */ + if (unlikely(curr->policy == SCHED_IDLE) && + likely(p->policy != SCHED_IDLE)) + goto preempt; + /* - * Batch and idle tasks do not preempt (their preemption is driven by - * the tick): + * Batch and idle tasks do not preempt non-idle tasks (their preemption + * is driven by the tick): */ if (unlikely(p->policy != SCHED_NORMAL)) return; - /* Idle tasks are by definition preempted by everybody. */ - if (unlikely(curr->policy == SCHED_IDLE)) - goto preempt; if (!sched_feat(WAKEUP_PREEMPT)) return; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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