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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 32BECC433DB for ; Mon, 11 Jan 2021 14:40:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C247221F8 for ; Mon, 11 Jan 2021 14:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388353AbhAKOkX (ORCPT ); Mon, 11 Jan 2021 09:40:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729285AbhAKOkX (ORCPT ); Mon, 11 Jan 2021 09:40:23 -0500 Received: from mail-lj1-x22d.google.com (mail-lj1-x22d.google.com [IPv6:2a00:1450:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6BABC061794 for ; Mon, 11 Jan 2021 06:39:42 -0800 (PST) Received: by mail-lj1-x22d.google.com with SMTP id u21so3818268lja.0 for ; Mon, 11 Jan 2021 06:39:42 -0800 (PST) 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=a+vkcHsiAqswgM9MUlspMKBKOzyC4WpGMlRs5sRsV94=; b=gtfDv0DTmxcgQyGM5dFRLwMQ1L1sDYTjaAYhwgMBTRaKAVMZcno6eWHnO9cNrkSaae wi7zBfHEqacEAvTQKockZxaIu1bdRZ32ao8z3j1TYi05DGOKGBlTCpdJ6iYwpdEbwSn+ eV9uEXYLylQo19h0lNSDaYxupYbAD8HBK3mpactKaU4uFRlT4Srj3C0j0HJsKm7N/EMj NNTj9duGYmApdDNRq954LDNFEMoM6ZqU+r2spypaL2ku2ymBA2WQga/TRLL49oSnlNp/ Q99UQ/jlU/Mh8yOAJUBa2Kcu/r2YR6Je4/0Jlc6D5PODqKQstK6ID37UowpWKBoE/pKh T/aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=a+vkcHsiAqswgM9MUlspMKBKOzyC4WpGMlRs5sRsV94=; b=OOY1eMTG9vmRhDN07y3DDoj7Qlo/4qR5r1mnJ/YJzUFEwuNMUC4Ote/IRuxGKqVibC akkPdA3Z7QiaRdBF/yMcH0ywFaiT4pk/phViKQcNRTYW+cOVzVta3iq9AnUsnpnZ0nbk byJuHF2PwsXZ1591mBdc+z7xOsMSDN5SbqqZYMK0mLrmCNLmzYu7+jyVwEVDruiKk9Zv Jgz/dfMf1bWTh6M4wj/9W2uvLDFS7uRDovBvsXksYOsxumCo4H5FUtCkzHzVqU4UZl/C aqSnUIt4dpKZPRPk1tw9bpdsuqGxvrznLsX4UsBl3De+aSrj0W1/ji0K8baBjhcYUlqv yatg== X-Gm-Message-State: AOAM532hlZusOy7baTifVYNIo9ccF/gvLN/p69yGWduE9zwloD3aPNGb WYYIXu0ov9tB95qRbsdGe6qTP3DSS1fMSnQq9+uCHA== X-Google-Smtp-Source: ABdhPJwudvHcNGRWcUJycLu57rDSTV0lI86xj/Mc4NZOWgfOwiTAovNbt55DmReaufGCsbLUokwbJgaaHQReBSZ4UbU= X-Received: by 2002:a05:651c:20b:: with SMTP id y11mr7013834ljn.176.1610375981282; Mon, 11 Jan 2021 06:39:41 -0800 (PST) MIME-Version: 1.0 References: <20201214164822.402812729@infradead.org> <20201214170017.877557652@infradead.org> <20201215075911.GA3040@hirez.programming.kicks-ass.net> <20210108102738.GB3592@techsingularity.net> <20210108144058.GD3592@techsingularity.net> In-Reply-To: From: Vincent Guittot Date: Mon, 11 Jan 2021 15:39:29 +0100 Message-ID: Subject: Re: [RFC][PATCH 1/5] sched/fair: Fix select_idle_cpu()s cost accounting To: Peter Zijlstra Cc: Mel Gorman , "Li, Aubrey" , linux-kernel , Ingo Molnar , Juri Lelli , Valentin Schneider , Qais Yousef , Dietmar Eggemann , Steven Rostedt , Ben Segall , Tim Chen , Jiang Biao Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 8 Jan 2021 at 20:45, Peter Zijlstra wrote: > > On Fri, Jan 08, 2021 at 04:10:51PM +0100, Vincent Guittot wrote: > > Also, there is another problem (that I'm investigating) which is that > > this_rq()->avg_idle is stalled when your cpu is busy. Which means that > > this avg_idle can just be a very old and meaningless value. I think > > that we should decay it periodically to reflect there is less and less > > https://lkml.kernel.org/r/20180530143105.977759909@infradead.org > > :-) :-) I was more thinking of something like decaying avg_idle during tick_fair but at leat we all agree that we can't stay with a stalled avg_idle value