From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751877AbaKDDVn (ORCPT ); Mon, 3 Nov 2014 22:21:43 -0500 Received: from mail-pd0-f177.google.com ([209.85.192.177]:63339 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751762AbaKDDVl (ORCPT ); Mon, 3 Nov 2014 22:21:41 -0500 Message-ID: <5458462F.6000704@gmail.com> Date: Tue, 04 Nov 2014 11:21:19 +0800 From: Wanpeng Li User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Vincent Guittot , peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org, preeti@linux.vnet.ibm.com, Morten.Rasmussen@arm.com, kamalesh@linux.vnet.ibm.com, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org CC: riel@redhat.com, efault@gmx.de, nicolas.pitre@linaro.org, linaro-kernel@lists.linaro.org Subject: Re: [PATCH v8 08/10] sched: add SD_PREFER_SIBLING for SMT level References: <1414745252-4895-1-git-send-email-vincent.guittot@linaro.org> <1414745252-4895-9-git-send-email-vincent.guittot@linaro.org> In-Reply-To: <1414745252-4895-9-git-send-email-vincent.guittot@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vincent, On 14/10/31 下午4:47, Vincent Guittot wrote: > Add the SD_PREFER_SIBLING flag for SMT level in order to ensure that > the scheduler will put at least 1 task per core. What's the behavior before this patch? Regards, Wanpeng Li > > Signed-off-by: Vincent Guittot > Reviewed-by: Preeti U. Murthy > --- > kernel/sched/core.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 37fb92c..731f2ad 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -6165,6 +6165,7 @@ sd_init(struct sched_domain_topology_level *tl, int cpu) > */ > > if (sd->flags & SD_SHARE_CPUCAPACITY) { > + sd->flags |= SD_PREFER_SIBLING; > sd->imbalance_pct = 110; > sd->smt_gain = 1178; /* ~15% */ >