From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8C83C433EF for ; Mon, 13 Jun 2022 09:08:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239720AbiFMJIs (ORCPT ); Mon, 13 Jun 2022 05:08:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240558AbiFMJIh (ORCPT ); Mon, 13 Jun 2022 05:08:37 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63F7F1085 for ; Mon, 13 Jun 2022 02:08:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655111316; x=1686647316; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=/xfr7er5pb9mxRpWgXM+pcGqC+mkTeha9+7hr/drtQI=; b=EAVflvIUqux6I1Kkj9r4qxx4Ky4F6JHtx9S1P2t+s3DR9x/RoMUQSPDS TQXKX8X3wQRkdvtVvwCtvgzUG15acqpoOaijnXTETSUIDVsjzbNgCmMd0 qhqH5IvwrNPspsJVDqxe38gWoRnanCQSBpf2GLH8C2/B16lfG0/t6/EqL svkAXGtSgCan1etW2oJgli8Wsk8zel0j8U98zo6bkM2apF4viMNnnrrXX IoNKDbQQBTHUfB/4wgUacTsCrxpsxa01pSnrniwZgZjDYWsNfqa5mZsXM ljcsjpSUzLcExQeXZbGfcxuV+svRq3Vu4FDcHdM4+26SnerRoSE68qSEn g==; X-IronPort-AV: E=McAfee;i="6400,9594,10376"; a="258662354" X-IronPort-AV: E=Sophos;i="5.91,297,1647327600"; d="scan'208";a="258662354" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2022 02:08:36 -0700 X-IronPort-AV: E=Sophos;i="5.91,296,1647327600"; d="scan'208";a="639627927" Received: from xiruzha-mobl1.ccr.corp.intel.com (HELO chenyu5-mobl1) ([10.249.169.88]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2022 02:08:29 -0700 Date: Mon, 13 Jun 2022 17:08:26 +0800 From: Chen Yu To: Mel Gorman Cc: Yicong Yang , Peter Zijlstra , Vincent Guittot , yangyicong@hisilicon.com, Ingo Molnar , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Barry Song <21cnbao@gmail.com>, Srikar Dronamraju , Len Brown , Ben Segall , Aubrey Li , Abel Wu , Daniel Bristot de Oliveira , Tim Chen , linux-kernel@vger.kernel.org, K Prateek Nayak , Mohini Narkhede Subject: Re: [PATCH v4] sched/fair: Introduce SIS_UTIL to search idle CPU based on sum of util_avg Message-ID: <20220613090826.GA36036@chenyu5-mobl1> References: <20220612163428.849378-1-yu.c.chen@intel.com> <20220613080636.GA32587@chenyu5-mobl1> <20220613085437.GC3195@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220613085437.GC3195@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 13, 2022 at 09:54:37AM +0100, Mel Gorman wrote: > On Mon, Jun 13, 2022 at 04:06:36PM +0800, Chen Yu wrote: > > On Mon, Jun 13, 2022 at 03:40:52PM +0800, Yicong Yang wrote: > > > On 2022/6/13 0:34, Chen Yu wrote: > > > > > > [cut...] > > > > #define NUMA_IMBALANCE_MIN 2 > > > > diff --git a/kernel/sched/features.h b/kernel/sched/features.h > > > > index 1cf435bbcd9c..3334a1b93fc6 100644 > > > > --- a/kernel/sched/features.h > > > > +++ b/kernel/sched/features.h > > > > @@ -61,6 +61,7 @@ SCHED_FEAT(TTWU_QUEUE, true) > > > > * When doing wakeups, attempt to limit superfluous scans of the LLC domain. > > > > */ > > > > SCHED_FEAT(SIS_PROP, true) > > > > +SCHED_FEAT(SIS_UTIL, true) > > > > > > > > > > confused here that shouldn't we have SCHED_FEAT(SIS_PROP, false)? With SIS_UTIL enabled, SIS_PROP will have no > > > effect since nr is overridden by SIS_UTIL. > > Yes, no matter what SIS_PROP is set, the result of SIS_UTIL would be used to decide > > the scan depth. We don't change the default value of SIS_PROP here, as this patch > > tends to only touch one feature at one time. And the options could be tuned by user via > > sysfs manually. Besides, the target is to replace SIS_PROP with another search policy, > > Peter mentioned that "And ideally we're remove SIS_PROP after a few releases if this > > works out", so I assume that changing the default value of SIS_PROP does not matter > > in current patch. > > > > I had expected it to be disabled given that SIS_PROP does work to > calculcate nr, I see, disable SIS_PROP would reduce duplicated nr calculation. > then discards it, and uses SIS_UTIL. If SIS_UTIL shows a > regression and reports a bug, the first step would be to disable > SIS_UTIL and enable SIS_PROP via sched_feat. OK, I'll change it in next version. thanks, Chenyu > > -- > Mel Gorman > SUSE Labs