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 E051CC4332F for ; Mon, 14 Nov 2022 10:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235862AbiKNKlD (ORCPT ); Mon, 14 Nov 2022 05:41:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230306AbiKNKlB (ORCPT ); Mon, 14 Nov 2022 05:41:01 -0500 Received: from mail-il1-x134.google.com (mail-il1-x134.google.com [IPv6:2607:f8b0:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 117C21A062 for ; Mon, 14 Nov 2022 02:41:00 -0800 (PST) Received: by mail-il1-x134.google.com with SMTP id k18so1055295ilh.4 for ; Mon, 14 Nov 2022 02:41:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=YSq7cWIB6P+a2k/y/wp/mUypj4MJCRulYoRIkzaE0+8=; b=oTD3n6cISrgD9l2tpj7R3yBuSB3R2N01Ovpt82mzXJq0YNotI2tWwYY/ie+a8mT4dj gObHSnvcJJjf90IMfWAhccB9ht3q51hMQZn2GWpRR6fspAUDi7iRPNMxm+fVd0X8O09o VrIhC6CZhVd8uPyxbkpzHktgOVq+/89AXb0ofxOd8eHohap49AcyT69sMqnG0r/wctGQ zf7dXXcOFIEiSuWGAwzjhJJ1/h1DuRu9o82N4nbm4tvd4q/TW1VAbQMeP8/IkA/JAXkx iF0RpeNuD6TnkP6Lrpf625Q00meU5Ahw/11dw6XVd8Ta37WS/sNYnQiCGqdZ+Lo/m4ec oImA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=YSq7cWIB6P+a2k/y/wp/mUypj4MJCRulYoRIkzaE0+8=; b=ucY6RGCiANAORqw7vYLlBMST/Kkwgh3UagMKjYobTt6AJNH3tTyjbXMSBMlbd73wnM 1U5flt1XqpypSFsDqtLx0EbmwB0c2hwt3uSTKM1gSy3n+Jcktncmhg9gQkIGuezAI+q7 tOlF5Z/BBz92/IFZ5xx1/1VoV7f2MxziQq93Nrfyw7vytog5Xtt1LuFJwMYhn5CM1Yhq gVVdyGI3sBOiBbijgsihDv0kJHvYSeoYohmqpwKL4Mwlk8DOnepAoYazPoMwyIW4oMtz WjucLP25uT090wMGyGfnKxX1zWn3B7IAMP5zGrlVxOBR4NHF1Pkb2EKOiuJNj87VnC7f 4BHA== X-Gm-Message-State: ANoB5plpcyO8FHc9sU+dc87RVAWC59WJypRllc/Oa+mRktEpuRGPwhAa cB4L5OHVFPXcFkAdc81X/nHZK75z4eHQg0Ac7o5/WQ== X-Google-Smtp-Source: AA0mqf5bmycfAfaoHtsRwsrbTySxXmW0cYgyOPsnIDtLzER2bmqn9aHElP+yMajZEyuPgr5OJzC/zDHvDGC2dsxBsIY= X-Received: by 2002:a92:ad07:0:b0:2fa:8eb:ffec with SMTP id w7-20020a92ad07000000b002fa08ebffecmr6087711ilh.31.1668422459358; Mon, 14 Nov 2022 02:40:59 -0800 (PST) MIME-Version: 1.0 References: <20221028093403.6673-1-vincent.guittot@linaro.org> <78d06985-c31a-cdbf-08ef-5b4772a81a03@linux.vnet.ibm.com> In-Reply-To: <78d06985-c31a-cdbf-08ef-5b4772a81a03@linux.vnet.ibm.com> From: Vincent Guittot Date: Mon, 14 Nov 2022 11:40:47 +0100 Message-ID: Subject: Re: [PATCH v7 0/9] Add latency priority for CFS class To: shrikanth suresh hegde Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, parth@linux.ibm.com, qais.yousef@arm.com, chris.hyser@oracle.com, patrick.bellasi@matbug.net, David.Laight@aculab.com, pjt@google.com, pavel@ucw.cz, tj@kernel.org, qperret@google.com, tim.c.chen@linux.intel.com, joshdon@google.com, timj@gnu.org, kprateek.nayak@amd.com, yu.c.chen@intel.com, youssefesmat@chromium.org, joel@joelfernandes.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 13 Nov 2022 at 09:51, shrikanth suresh hegde wrote: > > > > This patchset restarts the work about adding a latency priority to describe > > the latency tolerance of cfs tasks. > > Hi Vincent. > > Tested the patches on the power10 machine. It is 80 core system with SMT=8. i.e > total of 640 cpus. on the large workload which mainly interacts with the > database there is minor improvement of 3-5%. > > the method followed is creating a cgroup, assigning a latency nice value of -20, > -10, 0 and adding the tasks to procs of the cgroup. outside of cgroup, stress-ng > load is running and it is not set any latency value. stress-ng --cpu=768 -l 50 > > with microbenchmarks, hackbench the values are more or less the same. for large > process pool of 60, there is 10% improvement. schbench tail latencies show > significant improvement with low and medium load upto 256 groups. only 512 > groups shows a slight decline. > > Hackbench (Iterations or N=50) > Process 6.1_Base 6.1_Latency_Nice > 10 0.13 0.14 > 20 0.18 0.18 > 30 0.24 0.25 > 40 0.34 0.33 > 50 0.40 0.41 > 60 0.53 0.49 > > schbench (Iterations or N=5) > > Groups: 1 > 6.1_Base 6.1_Latency_Nice > 50.0th: 10.8 9.8 > 75.0th: 12.4 11.4 > 90.0th: 14.2 13.2 > 95.0th: 15.6 14.6 > 99.0th: 27.8 19.0 > 99.5th: 38.0 21.6 > 99.9th: 66.2 25.4 > > Groups: 2 > 6.1_Base 6.1_Latency_Nice > 50.0th: 11.2 10.8 > 75.0th: 13.2 12.4 > 90.0th: 15.0 15.0 > 95.0th: 16.6 16.6 > 99.0th: 22.4 22.8 > 99.5th: 23.8 27.8 > 99.9th: 30.2 45.6 > > Groups: 4 > 6.1_Base 6.1_Latency_Nice > 50.0th: 13.8 11.2 > 75.0th: 16.0 13.2 > 90.0th: 18.6 15.2 > 95.0th: 20.4 16.6 > 99.0th: 28.8 21.6 > 99.5th: 48.8 25.2 > 99.9th: 900.2 47.0 > > Groups: 8 > 6.1_Base 6.1_Latency_Nice > 50.0th: 17.8 14.4 > 75.0th: 21.8 17.2 > 90.0th: 25.4 20.4 > 95.0th: 28.0 22.4 > 99.0th: 52.8 28.4 > 99.5th: 156.4 32.6 > 99.9th: 1990.2 52.0 > > Groups: 16 > 6.1_Base 6.1_Latency_Nice > 50.0th: 26.0 21.0 > 75.0th: 33.0 27.8 > 90.0th: 39.6 34.4 > 95.0th: 43.4 38.6 > 99.0th: 66.8 48.8 > 99.5th: 170.6 60.6 > 99.9th: 3308.8 201.6 > > Groups: 32 > 6.1_Base 6.1_Latency_Nice > 50.0th: 40.8 38.6 > 75.0th: 55.4 52.8 > 90.0th: 67.0 64.2 > 95.0th: 74.2 71.6 > 99.0th: 106.0 90.0 > 99.5th: 323.8 133.0 > 99.9th: 4789.6 459.2 > > Groups: 64 > 6.1_Base 6.1_Latency_Nice > 50.0th: 72.6 68.2 > 75.0th: 103.4 97.8 > 90.0th: 127.6 120.0 > 95.0th: 141.2 132.0 > 99.0th: 343.4 158.4 > 99.5th: 1609.0 180.8 > 99.9th: 6571.2 686.6 > > Groups: 128 > 6.1_Base 6.1_Latency_Nice > 50.0th: 147.2 147.2 > 75.0th: 216.4 217.2 > 90.0th: 268.4 268.2 > 95.0th: 300.6 294.8 > 99.0th: 3500.0 638.6 > 99.5th: 5995.2 2522.8 > 99.9th: 10390.4 9451.2 > > Groups: 256 > 6.1_Base 6.1_Latency_Nice > 50.0th: 340.8 333.2 > 75.0th: 551.8 530.2 > 90.0th: 3528.4 1919.2 > 95.0th: 7312.8 5558.4 > 99.0th: 14630.4 12912.0 > 99.5th: 17955.2 14950.4 > 99.9th: 23059.2 20230.4 > > Groups: 512 > 6.1_Base 6.1_Latency_Nice > 50.0th: 1021.8 990.6 > 75.0th: 9545.6 10044.8 > 90.0th: 20972.8 21638.4 > 95.0th: 29971.2 30291.2 > 99.0th: 42355.2 46707.2 > 99.5th: 48550.4 52057.6 > 99.9th: 58867.2 60147.2 > > Tested-by: shrikanth Hegde Thanks for the tests and the results >