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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED 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 79679ECDE44 for ; Sun, 28 Oct 2018 11:05:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B26120665 for ; Sun, 28 Oct 2018 11:05:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=aol.com header.i=@aol.com header.b="neqo9wFS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B26120665 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=aol.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727503AbeJ1TuG (ORCPT ); Sun, 28 Oct 2018 15:50:06 -0400 Received: from sonic301-21.consmr.mail.gq1.yahoo.com ([98.137.64.147]:33460 "EHLO sonic301-21.consmr.mail.gq1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727065AbeJ1TuG (ORCPT ); Sun, 28 Oct 2018 15:50:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1540724746; bh=sUVEpUzLHerQbzVzMAyN3TNpJJBFHrv2o+nirERAh88=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From:Subject; b=neqo9wFSSpXgdzI5KVnYeIm3wfMF1/bfOBKYSd65z7r4gOZklaQ7vaoY/k8JlZyusgYjHIRcUCwHp9YXxqacg8JQY5L5PTaAyx3OUS1uElB3toKpj7gnwVp7uCDO5iJTyi8FIchPxHdI93Tr05eKMRQ7J+x7dMXd9CZ6MLx2/ZZ273IT7kaSKGLXkLY7UvdUBdsOWSC++jJSQkmvPYjBBsy9bl5khSjsy3Qq+zd+IxEGUcRhFmqrQ8ZFcfY4y5SkxZdfF2hrOzAQiNGcEmi4/j3n+tVjN0rOx4idnYaHtoNO/IDxiEQLX2v8sCnCnYcawqEwUwarzTxrzTW4Tq6K/A== X-YMail-OSG: .XSLIU0VM1l8ySmwxDfWhivFDa6tnu_Fn_6HnrZu_P.1Dst5imJv1pn9OI0y3ah SAcn2pTGlZH7itFvom4dZmfJY4giTCAEdKw39m8tHXxikzSHpSqpMQD3ujkYO7hGGeMv8L1jzYKT HwkObUGz6SLHTGsGcioGVzKavFJEUfnhZdLGTBRJaxaFaoLn08yIaVesdMUKHcnEOlEt3nZNlQFk x10Mu2._lJe3LE3uTkVTgtP9bW3W8s6EGPMPdktArO8K82D1WkAQs7qwB4Nombo2Vgg27N1_p82L 2sVTs114xYJo0TCE2510mGUzRK0SGpxLc9vW7Kko0057vlp4lNgdbOD3tzT_bJATum26wtzLywhb 9OtBT25B2zaXiAeRAMgT5peagrf0qwQ_kfK3XHJDQob99K94StTDqAsNdyCYsXkh3v.pRbAOwQR2 djezRi46k9HUBcgjM_0AuqT4VesCIj4Mebl0suQnCK790pdrbwukqlAPBnuUHPtZPjRs.mwvuCd_ vK2TDxDPhjTSeH.iicbduyaSJSlLY8V3CBT6cgKxSLUBLOVYMrdR4XuvgJuXGbbgInxckkbx2pv. pYYFqtAtzLYmRnAt7.3z5SaujiJ1SB_qUcOl7x5dKCR4PZF4WsxWUblvMEoDbQ1mQfiRMHIgpOBc aUYBuDGB66KuEbsN3DCtQ4nJf_elaNnnpP0F6MPSdDONsZrJjtlIR3wM5l5KYecbTmi76Shk64IR o5H03D7jE0MZs_0HSLJF8kaRuFSRl7ZNA1tQ6_sJpHJDQwnmqFLPiUqAyQPHJperxyvho.zFxlBA J_wBzKRIkhzK3C3Fj7OmQyJo8pF2wVPvQcbHJqjCYCPPgEeJLS.rYboef7Mk6GBrymq_RBfw8uF0 uQpxJz8YgnpBCoOCqgJdmrcbGnygu2GL4yyJ2EOmFKrOt_aOyAAxoZw7WifFyiQyZNPcqvmtwLp_ vp51VOKgpmVgMKXgpC8j5xMbfkEl8YSAfzA2xUpaQNFvzdqILZs4iZR4PkB_Hj3rbxiySheGItZX n4nm7Pd3Kl5F0KbAnFyx26RZpG73FNgajMK0QFTdD Received: from sonic.gate.mail.ne1.yahoo.com by sonic301.consmr.mail.gq1.yahoo.com with HTTP; Sun, 28 Oct 2018 11:05:46 +0000 Received: from 115.192.33.5 (EHLO [192.168.199.211]) ([115.192.33.5]) by smtp418.mail.gq1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 6a3374165f371d3e4b27453eae07b9dc; Sun, 28 Oct 2018 11:05:44 +0000 (UTC) Subject: Re: [PATCH] mm: simplify get_next_ra_size To: Matthew Wilcox Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Fengguang Wu References: <1540707206-19649-1-git-send-email-hsiangkao@aol.com> <20181028102346.GC25444@bombadil.infradead.org> From: Gao Xiang Message-ID: Date: Sun, 28 Oct 2018 19:05:39 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181028102346.GC25444@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matthew, On 2018/10/28 18:23, Matthew Wilcox wrote: > On Sun, Oct 28, 2018 at 02:13:26PM +0800, Gao Xiang wrote: >> It's a trivial simplification for get_next_ra_size and >> clear enough for humans to understand. >> >> It also fixes potential overflow if ra->size(< ra_pages) is too large. >> >> Cc: Fengguang Wu >> Signed-off-by: Gao Xiang > > Reviewed-by: Matthew Wilcox > > I also considered what would happen with underflow (passing a 'max' > less than 16, or less than 2) and it would seem to do the right thing > in that case. Yeah, thanks for the review ;) I also made a simple tester to test this in order to ensure its correctness and the result shows the same behavior except for the overflowed case. Thanks, Gao Xiang >