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=-9.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,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 71418C4338F for ; Thu, 5 Aug 2021 17:13:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5192761102 for ; Thu, 5 Aug 2021 17:13:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238547AbhHERN1 (ORCPT ); Thu, 5 Aug 2021 13:13:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237497AbhHERN0 (ORCPT ); Thu, 5 Aug 2021 13:13:26 -0400 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5B26C061765 for ; Thu, 5 Aug 2021 10:13:11 -0700 (PDT) Received: by mail-pj1-x1033.google.com with SMTP id nh14so10468640pjb.2 for ; Thu, 05 Aug 2021 10:13:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=QA00P76bflJpvFVXRXCqF/ydJ5VOL2iYfCDbkN0GqY8=; b=dPL//LUqTtrv8CLM5kof9yFH7N2piQ/iZSo6IKnwqe6aj5AsKoXqNSIm7k7gjlxR8O iuzUumNd3+dySQUHoINH6ZvB7cYFzRnwohovKAaUAeBoejGAUrIzOHUBOugv3D9j/5CE 8L/RmhA0fyA7Xxm7rDs7T9A6IZxLETE0paOods9c+ot1mUkJOeOr2QMW83MnyDP6R5SG UEE7ncNeKzEmkjtosOO+xCKNwYqwv7SoOQBgwy6iFEGHcjI8cjvpwxFHbLA1lcIe6ggf 14HVTtNF4RRJEOP65jqQb3Pv/E7YIVdSPMARry9mZT3x2yd4qROW9JvMiKVmlZYfb+wp 9QMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=QA00P76bflJpvFVXRXCqF/ydJ5VOL2iYfCDbkN0GqY8=; b=dwkAiPrgckwgeLWuhfszY9ESIYYmYitz1DEHdm+EF5bpbaKj6l7Bi3gWbjeN0LzivR iTq4kTkOVeZJNfnzYZgYQl5DRLEfJ6owiiRnL8B9NgcQlTK61xLf7PhWLysKbIutbMR5 d6vVmn7LdUMTk++kNIGsG+DgfcOlhU+fM6KbcwYLi5vQlLUP+CRum2VHUqvWX8Wc4pII oxDswuiaORiNTlI9J3lMehamtmliAdFUUr/6+vz4SNkkGwanGF3sY3/WAFPTEsRPzh2z 0mDwZeLJ1ozTIyG+ERFhr3UksPCS2QqDJCDj6uvdIAI58deAeHP83v6JFfpqymvCUIbM kZew== X-Gm-Message-State: AOAM533EU+up086Ngs2fRXZGB3U2nOFQowpXKH4fehabZuCV77S1LvPc bLG2EWXtRVlTIPVUqdD1qY8= X-Google-Smtp-Source: ABdhPJxX4D3KwnOrHMR0fi0zPokEsF0OiWg9Ye/AaA06LrH3XFRI9rd5cNxLnJ9xehybB6O48X0hJw== X-Received: by 2002:a17:902:8bc3:b029:124:919f:6213 with SMTP id r3-20020a1709028bc3b0290124919f6213mr4867351plo.51.1628183591035; Thu, 05 Aug 2021 10:13:11 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:71c8]) by smtp.gmail.com with ESMTPSA id y26sm7412826pfp.176.2021.08.05.10.13.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Aug 2021 10:13:10 -0700 (PDT) Sender: Tejun Heo Date: Thu, 5 Aug 2021 07:13:06 -1000 From: Tejun Heo To: Peter Zijlstra Cc: Josh Don , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Paul Turner , Oleg Rombakh , Viresh Kumar , Steve Sistare , Rik van Riel , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] sched: cgroup SCHED_IDLE support Message-ID: References: <20210730020019.1487127-1-joshdon@google.com> <20210730020019.1487127-2-joshdon@google.com> <20210805101849.GH8057@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210805101849.GH8057@worktop.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Thu, Aug 05, 2021 at 12:18:49PM +0200, Peter Zijlstra wrote: > So I'm tempted to apply this, but last time TJ wasn't liking it much for > the interface or somesuch. His argument that this encodes the > hierarchical scheduling behaviour, but I'm not really buying that > argument, as it doesn't really add more constraints than we already have > by the hierarchical relative weight. Interface-wise, writing 1 to idle file is fine. This does move away the interface from being a purely semantical weight tree, which is a concern and I have a difficult time seeing that the stated benefits are significant enough to justify the changes. That said, this is primarily a scheduler decision, so if you think the addition is justified, please go ahead. Acked-by: Tejun Heo Thanks. -- tejun