From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752246AbbCWJOj (ORCPT ); Mon, 23 Mar 2015 05:14:39 -0400 Received: from mga01.intel.com ([192.55.52.88]:25309 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751918AbbCWJOh (ORCPT ); Mon, 23 Mar 2015 05:14:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,451,1422950400"; d="scan'208";a="696245587" From: Wanpeng Li To: Ingo Molnar , Peter Zijlstra Cc: Juri Lelli , linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH] sched/deadline: reduce rq lock contention by eliminating locking of non-feasible target Date: Mon, 23 Mar 2015 16:56:34 +0800 Message-Id: <1427100994-4613-1-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds checks 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 | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 19d716e..9577db0 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -955,7 +955,8 @@ 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 && + p->dl.deadline < cpu_rq(target)->dl.earliest_dl.curr) cpu = target; } rcu_read_unlock(); -- 1.9.1