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 X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C0B6C6369E for ; Thu, 19 Nov 2020 01:13:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49D822145D for ; Thu, 19 Nov 2020 01:13:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727369AbgKSBNP (ORCPT ); Wed, 18 Nov 2020 20:13:15 -0500 Received: from mga09.intel.com ([134.134.136.24]:16346 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727238AbgKSBNP (ORCPT ); Wed, 18 Nov 2020 20:13:15 -0500 IronPort-SDR: khWteIRhFpZKIFHirz4UMCmbAfCesiW45m6Ro3tzj6OkQM4pFdK6BXIsCj2tBtKs3tKVoxIk7U JpIZI5kIxx0g== X-IronPort-AV: E=McAfee;i="6000,8403,9809"; a="171382406" X-IronPort-AV: E=Sophos;i="5.77,488,1596524400"; d="scan'208";a="171382406" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Nov 2020 17:13:14 -0800 IronPort-SDR: XmnOwdhb8nBV3dHO8tLz40nMCMV+mCwGfBBqVBauiLe47xX0C16JKgqz6Vi7zGNsjXmb0UWfN9 Q96ogSJl3Tkw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,488,1596524400"; d="scan'208";a="368576551" Received: from cli6-desk1.ccr.corp.intel.com (HELO [10.239.161.125]) ([10.239.161.125]) by FMSMGA003.fm.intel.com with ESMTP; 18 Nov 2020 17:13:10 -0800 Subject: Re: [RFC PATCH v4] sched/fair: select idle cpu from idle cpumask for task wakeup To: Valentin Schneider Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, mgorman@techsingularity.net, qais.yousef@arm.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, tim.c.chen@linux.intel.com, linux-kernel@vger.kernel.org, Aubrey Li , Mel Gorman , Jiang Biao References: <20201116200428.47359-1-aubrey.li@linux.intel.com> From: "Li, Aubrey" Message-ID: Date: Thu, 19 Nov 2020 09:13:09 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/11/18 20:06, Valentin Schneider wrote: > > On 16/11/20 20:04, Aubrey Li wrote: >> From: Aubrey Li >> >> Add idle cpumask to track idle cpus in sched domain. When a CPU >> enters idle, if the idle driver indicates to stop tick, this CPU >> is set in the idle cpumask to be a wakeup target. And if the CPU >> is not in idle, the CPU is cleared in idle cpumask during scheduler >> tick to ratelimit idle cpumask update. >> >> When a task wakes up to select an idle cpu, scanning idle cpumask >> has low cost than scanning all the cpus in last level cache domain, >> especially when the system is heavily loaded. >> >> Benchmarks were tested on a x86 4 socket system with 24 cores per >> socket and 2 hyperthreads per core, total 192 CPUs. Hackbench and >> schbench have no notable change, uperf has: >> >> uperf throughput: netperf workload, tcp_nodelay, r/w size = 90 >> >> threads baseline-avg %std patch-avg %std >> 96 1 0.83 1.23 3.27 >> 144 1 1.03 1.67 2.67 >> 192 1 0.69 1.81 3.59 >> 240 1 2.84 1.51 2.67 >> >> Cc: Mel Gorman >> Cc: Vincent Guittot >> Cc: Qais Yousef >> Cc: Valentin Schneider >> Cc: Jiang Biao >> Cc: Tim Chen >> Signed-off-by: Aubrey Li > > That's missing a v3 -> v4 change summary > okay, I'll add in the next version soon. Thanks, -Aubrey