From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753236AbbDBImi (ORCPT ); Thu, 2 Apr 2015 04:42:38 -0400 Received: from mga01.intel.com ([192.55.52.88]:27658 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753022AbbDBIm2 (ORCPT ); Thu, 2 Apr 2015 04:42:28 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,509,1422950400"; d="scan'208";a="707820366" From: Wanpeng Li To: Ingo Molnar , Peter Zijlstra Cc: Juri Lelli , linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH 3/3] sched/deadline: reduce rq lock contention by eliminating locking of non-feasible target Date: Thu, 2 Apr 2015 16:23:58 +0800 Message-Id: <1427963038-4561-3-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1427963038-4561-1-git-send-email-wanpeng.li@linux.intel.com> References: <1427963038-4561-1-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 This patch adds check that prevents futile attempts to move dl tasks to a CPU with active tasks of equal or earlier deadline. The same behavior as commit 80e3d87b2c55 ("sched/rt: Reduce rq lock contention by eliminating locking of non-feasible target") for rt class. Signed-off-by: Wanpeng Li --- kernel/sched/deadline.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 37425fd..e72194f 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1012,7 +1012,9 @@ select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags) (p->nr_cpus_allowed > 1)) { int target = find_later_rq(p); - if (target != -1) + if (target != -1 && + dl_time_before(p->dl.deadline, + cpu_rq(target)->dl.earliest_dl.curr)) cpu = target; } rcu_read_unlock(); -- 1.9.1