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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 14877C43387 for ; Wed, 19 Dec 2018 15:06:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D622F20874 for ; Wed, 19 Dec 2018 15:06:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="ZOz46dXO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729589AbeLSPGN (ORCPT ); Wed, 19 Dec 2018 10:06:13 -0500 Received: from mail-io1-f66.google.com ([209.85.166.66]:34048 "EHLO mail-io1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727071AbeLSPGL (ORCPT ); Wed, 19 Dec 2018 10:06:11 -0500 Received: by mail-io1-f66.google.com with SMTP id l22so486425ioh.1 for ; Wed, 19 Dec 2018 07:06:10 -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=7IVY7up4ZUWiDFb47rYR96dExMpbNSxpyBQZO50QO8c=; b=ZOz46dXOUm0SuGlvn/mE5gzqC9AY7QEesK4Eg3ZXgzGqgAvmVlDeyMzPGGvai7FM/x IMD/py+YqDgAAf13hjKd0IMsCZhEbsntAmx8smeRu3USz8VYW1AuXUDrSfuvhC2e326I 1V4S2yXCJz6rZki1ll6olUGvKld7OupvfFvGs= 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=7IVY7up4ZUWiDFb47rYR96dExMpbNSxpyBQZO50QO8c=; b=OL0jqDMXKAkQkv2mVQWbqRyF1BzcS5QggIluQjot3+s63DSE8nSQhu39IQCuOJtAj1 p8c+0XiskeKdyHAjRJZwxBGGSyEbfTdLPRWHC+yojNKb67+zuLEfFXTelThSAKBRpCHr dfCrWUw+vbFLFIUGwEl1u3VBvlmvI/VwEx6jwvLAdjxiTEVAGymDEXFFTW6nBhc6z3dq yX995Ndn5iOqiwqHop/d/+Yo0Cpb1nMzovM3VfjBMD2LjmAVmiSPc7I19fL3lmJzyWly Ha65QIeNyyx9nsKhwKAGXHAwnw2pUNmXLKCRQ+wDfLYH4k0bShM0KYJIe6Wqp3ZPMzwW y02w== X-Gm-Message-State: AA+aEWa2XQxS0mOEignIzY1h7UtPgS9O8hwCaj5aZHBEZ8XCIYMMvPfj 1myrWmcsPUw8WmfXiQNS1PD823hGEMPeubPAu0BeCw== X-Google-Smtp-Source: AFSGD/VA2PVcxzLiNCfuUYYLwYopSKAClxj3q2OqH/w+mHXAS9YX7CM9AybWM/7E90LJAciOlA96FlTEaqDKixrUc6Y= X-Received: by 2002:a6b:c8c9:: with SMTP id y192mr17281927iof.183.1545231970337; Wed, 19 Dec 2018 07:06:10 -0800 (PST) MIME-Version: 1.0 References: <1544803317-7610-1-git-send-email-vincent.guittot@linaro.org> <1544803317-7610-2-git-send-email-vincent.guittot@linaro.org> <4de22c37-fe65-4f5f-929b-320c663ee8b6@arm.com> <8ea1a96c-c2e0-cc3f-1cec-444706383e77@arm.com> In-Reply-To: <8ea1a96c-c2e0-cc3f-1cec-444706383e77@arm.com> From: Vincent Guittot Date: Wed, 19 Dec 2018 16:05:59 +0100 Message-ID: Subject: Re: [PATCH v2 1/3] sched/fair: fix rounding issue for asym packing To: Valentin Schneider Cc: Peter Zijlstra , Ingo Molnar , linux-kernel , Morten Rasmussen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 19 Dec 2018 at 15:59, Valentin Schneider wrote: > > > > On 19/12/2018 13:39, Vincent Guittot wrote: > [...] > >> I used that setup out of convenience for myself, but AFAICT that use-case > >> just stresses that issue. > > > > After looking at you UC in details, your problem comes from the wl=1 > > for cpu0 whereas there is no running task. > > But wl!=0 without running task should not be possible since fdf5f3 > > ("wsched/fair: Disable LB_BIAS by default") > > > > This explain the 1023 instead of 1022 > > > > > > True, I had a look at the trace and there doesn't seem to be any running > task on that CPU. That's a separate matter however - the rounding issues > can happen regardless of the wl values. But it means that the rounding fix +1 works and your problems comes from something else