Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753149AbbDFJMO (ORCPT ); Mon, 6 Apr 2015 05:12:14 -0400 Received: from mga09.intel.com ([134.134.136.24]:7462 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752898AbbDFJLr (ORCPT ); Mon, 6 Apr 2015 05:11:47 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,530,1422950400"; d="scan'208";a="477167899" From: Wanpeng Li To: Ingo Molnar , Peter Zijlstra Cc: Juri Lelli , linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH 7/7] sched/rt: reschedule if stop/dl task slip in after pull operations Date: Mon, 6 Apr 2015 16:53:19 +0800 Message-Id: <1428310399-13489-7-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1428310399-13489-1-git-send-email-wanpeng.li@linux.intel.com> References: <1428310399-13489-1-git-send-email-wanpeng.li@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1730 Lines: 54 pull_rt_task() can drop (and re-acquire) rq->lock, this means a dl or stop task can slip in, in which case need to reschedule. This patch add the reschedule when the scenario occurs. Signed-off-by: Wanpeng Li --- kernel/sched/rt.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 575da76..cc973e8 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2136,7 +2136,14 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p) if (!task_on_rq_queued(p) || rq->rt.rt_nr_running) return; - if (pull_rt_task(rq)) + /* + * pull_rt_task() can drop (and re-acquire) rq->lock; this + * means a dl or stop task can slip in, in which case we need + * to reschedule. + */ + if (pull_rt_task(rq) || + (unlikely((rq->stop && task_on_rq_queued(rq->stop)) || + rq->dl.dl_nr_running))) resched_curr(rq); } @@ -2197,6 +2204,16 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) */ if (oldprio < p->prio) pull_rt_task(rq); + + /* + * pull_rt_task() can drop (and re-acquire) rq->lock; this + * means a dl or stop task can slip in, in which case we need + * to reschedule. + */ + if (unlikely((rq->stop && task_on_rq_queued(rq->stop)) || + rq->dl.dl_nr_running)) + resched_curr(rq); + /* * If there's a higher priority task waiting to run * then reschedule. Note, the above pull_rt_task -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/