From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753400AbbDGJ5S (ORCPT ); Tue, 7 Apr 2015 05:57:18 -0400 Received: from mga09.intel.com ([134.134.136.24]:25733 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753335AbbDGJ5M (ORCPT ); Tue, 7 Apr 2015 05:57:12 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,537,1422950400"; d="scan'208";a="691347799" Date: Tue, 7 Apr 2015 17:38:57 +0800 From: Wanpeng Li To: Peter Zijlstra Cc: Ingo Molnar , Juri Lelli , linux-kernel@vger.kernel.org, Wanpeng Li Subject: Re: [PATCH v2] sched/deadline: reduce rq lock contention by eliminating locking of non-feasible target Message-ID: <20150407093856.GA6853@kernel> Reply-To: Wanpeng Li References: <1427101333-5841-1-git-send-email-wanpeng.li@linux.intel.com> <20150326230300.GA3658@kernel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150326230300.GA3658@kernel> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping Peter, this patch is collected into this patchset https://lkml.org/lkml/2015/4/6/44 On Fri, Mar 27, 2015 at 07:03:00AM +0800, Wanpeng Li wrote: >Ping Juri, ;) >On Mon, Mar 23, 2015 at 05:02:13PM +0800, Wanpeng Li wrote: >>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 >>--- >>v1 -> v2: >> * use dl_time_before macro >> >> 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 19d716e..f48d319 100644 >>--- a/kernel/sched/deadline.c >>+++ b/kernel/sched/deadline.c >>@@ -955,7 +955,9 @@ 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