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 62327C433E6 for ; Tue, 16 Mar 2021 10:56:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37E9D6500E for ; Tue, 16 Mar 2021 10:56:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236840AbhCPK4Z (ORCPT ); Tue, 16 Mar 2021 06:56:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229792AbhCPKzr (ORCPT ); Tue, 16 Mar 2021 06:55:47 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69325C06174A for ; Tue, 16 Mar 2021 03:55:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=fJg6GHGovgQHmM0kQSRyfXRZjcSHrNAE4iyqVwiI9no=; b=Ui/0k/XCr3zU8amLKvcet+NNTx OpMvSky/jZoK7ne15PGFMxvFBheONzSxh5OTD57Mn+qFXJ5PDh7xHatI9gzH8OEXHqZ+0PN8I58hZ pTYSPrMh6j60c7HgytvUboXSK5cOj/1e9qbTrM3Dwr5Nxhn5USLlFCLS4rgF8a7hVBqAwEFrACEXS mw6U0DUuoeheNi1M3qg8Sezd5Gl9V4vFEtHxRu+nIwN0gBYOpAKSAr3k2XPbdtcMgzvMAIA7BK1zD +G4PRSlcKfFXFLM1u1LiS7CbkbKA6Yoo591vvQCMvPkE2E6+5tp/Mp43VoxMkSAGhxamwhqvD5xtQ wnJwCpZQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lM7M0-000UQi-LA; Tue, 16 Mar 2021 10:55:12 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D38F73012DF; Tue, 16 Mar 2021 11:55:06 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B4F6920435CFD; Tue, 16 Mar 2021 11:55:06 +0100 (CET) Date: Tue, 16 Mar 2021 11:55:06 +0100 From: Peter Zijlstra To: changhuaixin Cc: Benjamin Segall , dietmar.eggemann@arm.com, juri.lelli@redhat.com, khlebnikov@yandex-team.ru, open list , mgorman@suse.de, mingo@redhat.com, pauld@redhead.com, Paul Turner , rostedt@goodmis.org, Shanpei Chen , Vincent Guittot , xiyou.wangcong@gmail.com Subject: Re: [PATCH v3 2/4] sched/fair: Make CFS bandwidth controller burstable Message-ID: References: <20210121110453.18899-1-changhuaixin@linux.alibaba.com> <20210121110453.18899-3-changhuaixin@linux.alibaba.com> <448372EF-B943-4E3E-8041-96884DF63BB8@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <448372EF-B943-4E3E-8041-96884DF63BB8@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 12, 2021 at 09:54:33PM +0800, changhuaixin wrote: > > On Mar 10, 2021, at 9:04 PM, Peter Zijlstra wrote: > > There's already an #ifdef block that contains that bandwidth_slice > > thing, see the previous hunk, so why create a new #ifdef here? > > > > Also, personally I think percentages are over-represented as members of > > Q. > > > Sorry, I don't quite understand the "members of Q". Is this saying that the percentages > are over-designed here? You know the number groups (in order): N, Z, Q, R, C, H, O. Percent being 1/100 is a fraction and thus part of Q (and anything higher ofcourse). Some people seem to think percent is magical and special. It's just a fraction like the inifinite many others in Q. It's also a very crappy one when we consider computers. Basically I hate percentages, they're nothing special and often employed where they should not be.