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 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 56E16C11F64 for ; Thu, 1 Jul 2021 11:10:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33ADA61450 for ; Thu, 1 Jul 2021 11:10:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236157AbhGALMg (ORCPT ); Thu, 1 Jul 2021 07:12:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236040AbhGALMf (ORCPT ); Thu, 1 Jul 2021 07:12:35 -0400 Received: from mail-qk1-x72d.google.com (mail-qk1-x72d.google.com [IPv6:2607:f8b0:4864:20::72d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A414C061756 for ; Thu, 1 Jul 2021 04:10:05 -0700 (PDT) Received: by mail-qk1-x72d.google.com with SMTP id 65so5593645qko.5 for ; Thu, 01 Jul 2021 04:10:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uged.al; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=xfGds6BnQUXnFsToXmVlpRl9EGFieOscnvQwxQdcuP8=; b=WRZs228ixfJZYLWmabOSw65BO6S9roOO0ovheIy6MDtgDgyIJRcs947IMvognXs6nf /0T2GTmpYT5BB/u1Uns7KRvWrEC+ASA+5vz4f1NOCe7ABpGwBhUjKT9mfuT3Ff4ymy6y 7QWqQj34ImZYeWbn0GJoOBf3r6ZB184i/D+GYoJ9BWBcd5NGR8xtVThs/UABmkH+IneH ylYQSJ5oV2buAFl+iwbrdyu8TRauIf83GYFON8mWCMGUL6OSTSuEeOffAyP+k1ajYTQW GJTLYmDxFpSIJPLLqQKpQY8E6p90L5RenascqSdUarQ1N0ePjZuN13FmIbZS9qqi9ywL HtzQ== 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=xfGds6BnQUXnFsToXmVlpRl9EGFieOscnvQwxQdcuP8=; b=C4rjmvqncSvVZfKpppajg1EUbhGHAIHVEbwmZuhW0orhGEZZvEEwMx4zFYAjAHTwy/ IVSgTgK3kqxW1tqPww52NoPwnpXhoyjIYa8WPt11+2XL6zr6msDe0unaHmzGkVSdIKsg 9KGgfMaGnW+L1m21hg+ASQjVoIxf75Wtf+BglyKnM5hrd/2V8JYI5vIwIJDjUCMaen19 EDsG4RYlpQ42bL+Lc7gF7sj8ag/I3XlReZYDJo6qUzrWQnhE5u0Cxn0vavD3erbwXK0v YrcXjXHeQ/A6DE4jYORnl9H6f0vqONXTwPrAQwdH6YbgBrLVk9h4/7s6MK6heWci9EB+ xVFw== X-Gm-Message-State: AOAM533bKT19mePoC/q8wUgZrKTI7fb6PyqqHOD/beUDvYeTXfnWpcoK OjkpdpdsEhxNBF1gdbo4ff7YSit5AwkK8tQmBv5kmA== X-Google-Smtp-Source: ABdhPJxK81/tXcxjZ99wIr+hQBWxN/HhS0cvOYye9PN4/sTZYjwU0kMpEcu7UQuFRSm3kQaCWrNJ/fCmcmbd/+uBDfY= X-Received: by 2002:ae9:dd06:: with SMTP id r6mr42243802qkf.74.1625137804041; Thu, 01 Jul 2021 04:10:04 -0700 (PDT) MIME-Version: 1.0 References: <20210624111815.57937-1-odin@uged.al> <20210701103448.GL3840@techsingularity.net> In-Reply-To: <20210701103448.GL3840@techsingularity.net> From: Odin Ugedal Date: Thu, 1 Jul 2021 13:09:33 +0200 Message-ID: Subject: Re: [PATCH] sched/fair: Ensure _sum and _avg values stay consistent To: Mel Gorman Cc: Sachin Sant , Odin Ugedal , Vincent Guittot , Peter Zijlstra , Naresh Kamboju , Ingo Molnar , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org tor. 1. jul. 2021 kl. 12:34 skrev Mel Gorman : > > What was HEAD when you checked this? 1c35b07e6d39 was merged in the > 5.14-rc1 merge window so would not be in 5.13. >From the kernel log it looks like he used commit dbe69e433722 (somewhere in Linus' tree), and that should include my patch. I don't think the patches from Vincent in the previous thread have been posted properly, and I think those can fix the edge case you are seeing. This should mitigate some issues: https://lore.kernel.org/lkml/20210622143154.GA804@vingu-book/ while https://lore.kernel.org/lkml/20210623071935.GA29143@vingu-book/ might also help in some cases as well. Both of those are needed to make sure that *_avg is zero whenever *_sum is zero. > # git log v5.13..origin/master --pretty=one | grep 1c35b07e > 1c35b07e6d3986474e5635be566e7bc79d97c64d sched/fair: Ensure _sum and _avg values stay consistent > > It's not tagged for stable and lacks a Fixes: tag so I don't think > it'll be automatically picked up for 5.13-stable unless Odin sends it > to stable@vger.kernel.org. Ahh, so the "Fixes" tag is what makes them pick it up... Thanks! I am fairly new to this, but it does make sense when I think about it. I have seen https://www.kernel.org/doc/html/v5.13/process/stable-kernel-rules.html before, so I guess I can send it to them to get it into -stable. The assertion is not a part of v5.13 either though, so people will not see this warning there (but it can still cause fairness issues). > -- > Mel Gorman > SUSE Labs Thanks Odin