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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E21CC433EF for ; Thu, 21 Oct 2021 12:42:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F29C60E05 for ; Thu, 21 Oct 2021 12:42:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230502AbhJUMod (ORCPT ); Thu, 21 Oct 2021 08:44:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230372AbhJUMob (ORCPT ); Thu, 21 Oct 2021 08:44:31 -0400 Received: from mail-qk1-x72b.google.com (mail-qk1-x72b.google.com [IPv6:2607:f8b0:4864:20::72b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFD51C06161C for ; Thu, 21 Oct 2021 05:42:15 -0700 (PDT) Received: by mail-qk1-x72b.google.com with SMTP id y10so1050256qkp.9 for ; Thu, 21 Oct 2021 05:42:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BiQuOAgT8bf0Gqc3SNvxUfomKy6p8NVPFxxm4Pd9on4=; b=fHIDggIX6AoIzwFryDzDFpdpk6ZM6gEKJ0WjsCdKKXFXm0b9XZRjEUibd19RuNDtiQ YoghFveEtWMRIbcBHMkZs4sRPxTLngeHpGzB1gO1eRs/mAHvIQcPPYwZdf2gIEXuV/ap RTcnLNBHrhMBxOilJX8Usvzja0PCLIt1YoaktLCDRviJi2dorm25/e6AzbIVhx81jzC8 hRuN2lNjhBhPX7xt4fp/kzb+27UO9pmRT6HmrMiAz8J1v0H/pRfsrFtBh9f55wogrlr4 Oie1MXwZLWzZ57JNOf6Mk3a+kodz3BDCZnMaOTDNcQeJB9yYM0ohtC2uOy7qgYhbtrNq A6uQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BiQuOAgT8bf0Gqc3SNvxUfomKy6p8NVPFxxm4Pd9on4=; b=xPLOritUZnmxmyN0Ut8etQpwu8vx7uLgRVn1gGbA04Lf9PQ0F4wCBH6jaGlF3F7B2J e1vh6i2buwb5yfoStqKIaFmrcRCVk7Zs08VECzj5V9nd55Ib5mCSYXUHGl9oRNx2f2Zx cHRMFCwchi91lrgEKc1o3oQaFzZoBWash35dltPacQKERSWX+xL6NP+qWWUsO3dXzWAp hmtv1F7zMhg7JU/nD6wvbzKMpZ9RRCCFOk6PCApQkPRhGPoyXQM3ia/lDbeHvGdutUbi zwGUefzza7Qcmfe4ZmNHk3U7b1U2AZysnEqL8A37M/tLSF0/Ug8MHa1RgsZf5me9WXkq z46A== X-Gm-Message-State: AOAM533eOG8AeS8ll/ZhfzJ3LBF9W/q3nE3V5ay7YNi7SWQCLNhxwLqP 5eZctcFeGLuAcjxBiHVJU9pIW+xvy04tKJQTZV0iNhOvmfY= X-Google-Smtp-Source: ABdhPJybXXEDfTU/yQ7WoXn8fXgWo8ZU2WpVitExz9LlBRi+hW0lh5lG1EsC755vFgrALvQkoLYDoY3wze+qY0RI46s= X-Received: by 2002:a25:73c5:: with SMTP id o188mr5845471ybc.61.1634820135059; Thu, 21 Oct 2021 05:42:15 -0700 (PDT) MIME-Version: 1.0 References: <20211019123537.17146-1-vincent.guittot@linaro.org> <20211021095219.GG3891@suse.de> In-Reply-To: <20211021095219.GG3891@suse.de> From: Vincent Guittot Date: Thu, 21 Oct 2021 14:42:03 +0200 Message-ID: Subject: Re: [PATCH v3 0/5] Improve newidle lb cost tracking and early abort To: Mel Gorman Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Daniel Bristot de Oliveira , linux-kernel , Tim Chen Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 21 Oct 2021 at 11:52, Mel Gorman wrote: > > On Tue, Oct 19, 2021 at 02:35:32PM +0200, Vincent Guittot wrote: > > This patchset updates newidle lb cost tracking and early abort: > > > > The time spent running update_blocked_averages is now accounted in the 1st > > sched_domain level. This time can be significant and move the cost of > > newidle lb above the avg_idle time. > > > > The decay of max_newidle_lb_cost is modified to start only when the field > > has not been updated for a while. Recent update will not be decayed > > immediatlybut only after a while. > > > > The condition of an avg_idle lower than sysctl_sched_migration_cost has > > been removed as the 500us value is quite large and prevent opportunity to > > pull task on the newly idle CPU for at least 1st domain levels. > > > > Monitoring sd->max_newidle_lb_cost on cpu0 of a Arm64 system > > THX2 (2 nodes * 28 cores * 4 cpus) during the benchmarks gives the > > following results: > > min avg max > > SMT: 1us 33us 273us - this one includes the update of blocked load > > MC: 7us 49us 398us > > NUMA: 10us 45us 158us > > > > > > Some results for hackbench -l $LOOPS -g $group : > > group tip/sched/core + this patchset > > 1 15.189(+/- 2%) 14.987(+/- 2%) +1% > > 4 4.336(+/- 3%) 4.322(+/- 5%) +0% > > 16 3.654(+/- 1%) 2.922(+/- 3%) +20% > > 32 3.209(+/- 1%) 2.919(+/- 3%) +9% > > 64 2.965(+/- 1%) 2.826(+/- 1%) +4% > > 128 2.954(+/- 1%) 2.993(+/- 8%) -1% > > 256 2.951(+/- 1%) 2.894(+/- 1%) +2% > > > > I read the patches earlier but had queued tests and waiting on the results > before Acking. The hackbench results were not bad, not a universal win, > but wins more than it loses with small decreaseds in system CPU usage. Thanks for running tests > > Most other results showed small gains or losses, nothing overly dramatic > and mostly within the noise. > > -- > Mel Gorman > SUSE Labs