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=-4.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 2F93CC12002 for ; Wed, 21 Jul 2021 13:09:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F087F61248 for ; Wed, 21 Jul 2021 13:09:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235479AbhGUM2m (ORCPT ); Wed, 21 Jul 2021 08:28:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234468AbhGUM2d (ORCPT ); Wed, 21 Jul 2021 08:28:33 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71AB6C061767 for ; Wed, 21 Jul 2021 06:08:58 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id t5so2118261wrw.12 for ; Wed, 21 Jul 2021 06:08:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=p4j+IB5ABbcQqTi2Z9gFZCErxz2KV+Poiy1HA/Do+ds=; b=HWGXeogxEr4/cdQYJz3iFSBi5416qINplAbl2FXo/cUGzOEa0+NQTyAFs36U66Eb29 Vxvt5uqrLGwk6cImlwUYMC+Ew4KHvh6OekyYJCPVFBeCtqGSdYeVILnT1jZaamMvPaqA v7Tb2eUMzH+f1sye0KTbGkJgfxTJTax4IKo8Ks0Ayh/z0vs0UyM3Vta96q4/6UvfCUG0 OnOhis5x4OI8awpdfJGtSIKhwCp19aX0ZOvnlGHSq7Iy6jEgo8vmOpC3x+lDKr6y55bd cqRgERRoNM1cSwk5oSSXMB+HqE3MBysvxllbTp1teD4p+SkB5L76mq+wLMoqKxA4VApB 0Fjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=p4j+IB5ABbcQqTi2Z9gFZCErxz2KV+Poiy1HA/Do+ds=; b=naw1YiyJAauD/7mU555qeCfzRYMsUxl9DWxAxKdzQotA1PWomjnZfr0UYTSGbd+1m9 cnkUb3oGPP3KxUrCA7n+i53Zqth98L3sAcct/J9uDqX9h3UMuELukB7fVsPC6BG/2aea XNLbtiOOyUeV6Xcfo47FS98G8ipinRLVp90cuHHyeJwDcMGl1NPThrdcPUqIQNr9HLj4 2PuVVh9ehcQUpgatbspgjCqksHEQokXUYYB8XXOZlbJPHCD/tuyQJpppUab8H6SaEwst z9sWLDNs3Su+k0zdQ0QHEMzXWxp4PL7i6pYVSCCjZpXSaRq08lwnU8VxxPR3tiRmMZEs 4S2w== X-Gm-Message-State: AOAM5323uMXLkAmEKyYDucTpEgA9PP3GYmJok1roXWrZiVb4ZP1H+jfN fDHxTYN8KvdSfS5OhfwoRdQ= X-Google-Smtp-Source: ABdhPJwKF+b0l7SD4byoxy+kFrWjKbCEMnAsTwNbtXX7B0tbrrKToykQSZQvFTaioimwE04Oavb/7A== X-Received: by 2002:a05:6000:d0:: with SMTP id q16mr4958169wrx.234.1626872937096; Wed, 21 Jul 2021 06:08:57 -0700 (PDT) Received: from ?IPv6:2a02:8084:e84:2480:228:f8ff:fe6f:83a8? ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id o14sm27279663wrj.66.2021.07.21.06.08.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 Jul 2021 06:08:56 -0700 (PDT) Subject: Re: [PATCH] mm/mremap: Don't account pages in vma_to_resize() To: Dmitry Safonov , linux-kernel@vger.kernel.org Cc: Alexander Viro , Andrew Morton , Andy Lutomirski , Brian Geffon , Catalin Marinas , Chen Wandun , Dan Carpenter , Dan Williams , Dave Jiang , Hugh Dickins , Ingo Molnar , Jason Gunthorpe , John Hubbard , Kefeng Wang , "Kirill A. Shutemov" , Mike Kravetz , Minchan Kim , Ralph Campbell , Russell King , Thomas Bogendoerfer , Thomas Gleixner , Vishal Verma , Vlastimil Babka , Wei Yongjun , Will Deacon References: <20210721124949.517217-1-dima@arista.com> From: Dmitry Safonov <0x7f454c46@gmail.com> Message-ID: Date: Wed, 21 Jul 2021 14:08:55 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210721124949.517217-1-dima@arista.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/21/21 1:49 PM, Dmitry Safonov wrote: > All this vm_unacct_memory(charged) dance seems to complicate the life > without a good reason. Furthermore, it seems not always done right on > error-pathes in mremap_to(). > And worse than that: this `charged' difference is sometimes > double-accounted for growing MREMAP_DONTUNMAP mremap()s in move_vma(): > : if (security_vm_enough_memory_mm(mm, new_len >> PAGE_SHIFT)) > > Let's not do this. > Account memory in mremap() fast-path for growing VMAs or in move_vma() > for actually moving things. And this one is also wrong: the diff for growing vma should be accounted for !MREMAP_DONTUNMAP too. Sending v2... Thanks, Dmitry