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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 88C3CC433E1 for ; Fri, 15 May 2020 09:04:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68D49206B6 for ; Fri, 15 May 2020 09:04:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589533486; bh=UyzUCdDrt5R2RkXVxXBajSJEoj87ZemtdIH/0a2QAKo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=SpDaIphCYKBA4Kc5YS8JZit/AO0g/bCKV58cabMWP8ShofZPuMM1iAOfvPOa5q/Vj 8oBlwcqEK9w5yNR3R707xgyqjgSbf5NffZEAFWq9h6rtslGHmj7M0d4aVA+D5tl1j+ yTKhjSJP5T23Gqxfd1nLhmD//OB3jWhfM3EPwc2Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728019AbgEOJEp (ORCPT ); Fri, 15 May 2020 05:04:45 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:35742 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726922AbgEOJEo (ORCPT ); Fri, 15 May 2020 05:04:44 -0400 Received: by mail-wr1-f65.google.com with SMTP id j5so2644586wrq.2 for ; Fri, 15 May 2020 02:04:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=9QDVZDXZoqSloGv08GEy2MAxiYOaCzJPvgAYS9OutzI=; b=RPKej9ipQyAOWjB+MJh5te19VycKFWmhJ1tftvjBczoSNPVZFW60Bm3pJ3VlfFiD3f Z6gd0z75HnUdGpcSHM8oYkjHLXKCVreLG84SDWz5sGwo/4NZymNliKel0k6sZbW8qh3t vQ0tbFuvXnNP56b+dfbWRXr6V2ZQAI/cfa8CZBxe4Cl0wxJNs/1qxJeJxeiCEtvUuDlN v0h8/A+PNDsyRFaNxY7sOn6JxW0iQAr4KU1mjK9aRNlTieR+mfEK4RlYkGTpmZhLiZOs /L8LmpwldpVqEMPMEBr59+An5M1GQH1Bf1fstUNTaW25+ye/IrLJmtSAUeclS0b2ZvIU HV2Q== X-Gm-Message-State: AOAM533kNr7zXWeQgBcbxL+2NTpft740xpAyuNHmi8cCHANN3zNbDdGq hMBLBdhV1SwSuDvgzlR6sz4= X-Google-Smtp-Source: ABdhPJy6OuUYUgPiVAlIah3CMGMVQCvfBn1TKTEVWtRuHvhUaoWQqy0w+nQkgDhq3DgMc1Ml/o1Vjg== X-Received: by 2002:a5d:530c:: with SMTP id e12mr3313165wrv.271.1589533482726; Fri, 15 May 2020 02:04:42 -0700 (PDT) Received: from localhost (ip-37-188-249-36.eurotel.cz. [37.188.249.36]) by smtp.gmail.com with ESMTPSA id m3sm2547773wrn.96.2020.05.15.02.04.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2020 02:04:41 -0700 (PDT) Date: Fri, 15 May 2020 11:04:40 +0200 From: Michal Hocko To: Feng Tang Cc: Andrew Morton , Johannes Weiner , Matthew Wilcox , Mel Gorman , Kees Cook , Luis Chamberlain , Iurii Zaikin , "Kleen, Andi" , "Chen, Tim C" , "Hansen, Dave" , "Huang, Ying" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/3] mm/util.c: make vm_memory_committed() more accurate Message-ID: <20200515090440.GN29153@dhcp22.suse.cz> References: <1588922717-63697-1-git-send-email-feng.tang@intel.com> <1588922717-63697-3-git-send-email-feng.tang@intel.com> <20200515072307.GG29153@dhcp22.suse.cz> <20200515081109.GD69177@shbuild999.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200515081109.GD69177@shbuild999.sh.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 15-05-20 16:11:09, Feng Tang wrote: > On Fri, May 15, 2020 at 03:23:07PM +0800, Michal Hocko wrote: > > On Fri 08-05-20 15:25:16, Feng Tang wrote: > > > percpu_counter_sum_positive() will provide more accurate info. > > > > Why do we need that? > > This is a preparation for patch 3/3, which will enlarge the batch size > of percpu-counter 'vm_committed_as'. Andi Kleen concerned that may > hurt the accuracy for those readers (currently only /proc/meminfo > and hyperV balloon drivers for status check) > > As in worst case, the deviation could be 'batch * nr_cpus', and > with patch 3/3, that could be totalram_pages/16. This information belongs to the changelog. -- Michal Hocko SUSE Labs