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=-9.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AA26DC6377A for ; Wed, 21 Jul 2021 20:18:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A58261222 for ; Wed, 21 Jul 2021 20:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233799AbhGUTh7 (ORCPT ); Wed, 21 Jul 2021 15:37:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232808AbhGUTh5 (ORCPT ); Wed, 21 Jul 2021 15:37:57 -0400 Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5357C061575 for ; Wed, 21 Jul 2021 13:18:33 -0700 (PDT) Received: by mail-wr1-x42f.google.com with SMTP id c12so3481397wrt.3 for ; Wed, 21 Jul 2021 13:18:33 -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=eaihz9yk/xIXyCpJhUj9DbEhmhohmopa6ht/rV/hojE=; b=bz2sjsPbm+Cmk5hqFS7XQjwhpZmvkxPv0JCBTscEr4LVqdlZumEouFJ3KjhkdUTMRd FY8rzzdPH38xQwmCHreRPkc3idSnSfzVVoo5lT0vLNAeh77oY3RR/wPODEuEUOdsPEal zGMiN+pX5Wpup2SRScWt5FK8bZXk04AgqfXdMQ4kZsykTHIVdKyOqvILk1VzWSsk4dii MY8coDRHS3yOqQBYVZcBZJhqbfGAuw+w5tqHzRKrAGnyit9M3/HfmQGVyj/21puUtLgJ cjTP/6OG76YxHqCd5iLLpw8+gcBFOgNu3NpDtPryU+LLIMxH7xK1WIBpeFFnRBVl/G+P F4fQ== 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=eaihz9yk/xIXyCpJhUj9DbEhmhohmopa6ht/rV/hojE=; b=s85y5ZS5TX+xs38u/dkLhqaISUjQjf7sKtpLxCMFq8xLBvZUh1kyH/gPrm/dXLNSSo PbyGodYfX4K2cmabnEKEd5vhJ5gnftAhGrw69IKYiQ2EopEmx2nzQ+jYdn/FvvXJxH0m zQHGNfEvVH7TfBHOJ7GJgltWuXbI2/2Yl2238f3jpIDkw/LBHUubT0bTkTPGL1Np/xB2 cSAMaCD03r00v9gs4/eyTApKcy/2rvReGxtW9O66h1nmpYJddkgeBNqEYt4AnXuTVAaW vOUP+NhtHcTlvFqqNv6UTM+AO8qmpdbKo8ztu42A5MmflT3cp2XZIhHswmtEm97+HWjy /CRQ== X-Gm-Message-State: AOAM530OesGh9cs3+KnICQZywuHKXCx1EWC90cevPSl0NNcZjjtRzG26 PTVzvxkwsmcN4nEVCs4s0jc= X-Google-Smtp-Source: ABdhPJyLgdF2CFy7WeSPj87r0Vtx6jKQCPotap0PKA1yvC0GYtGjUjZ/vuTwuIsj5BbrCuJFM7+NoA== X-Received: by 2002:a5d:5589:: with SMTP id i9mr34547422wrv.8.1626898712587; Wed, 21 Jul 2021 13:18:32 -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 n5sm21074723wrp.80.2021.07.21.13.18.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 Jul 2021 13:18:32 -0700 (PDT) Subject: Re: [PATCH v2] mm/mremap: Don't account pages in vma_to_resize() To: Dmitry Safonov , Andrew Morton , Brian Geffon Cc: linux-kernel@vger.kernel.org, Alexander Viro , Andy Lutomirski , 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: <20210721131320.522061-1-dima@arista.com> <77e28552-7a13-0981-f921-cd027cb73525@gmail.com> <20210721130551.bbdeae56ca3ec2d0f28b0bac@linux-foundation.org> <48ba72b8-3da2-e438-6148-5ec22172d475@arista.com> From: Dmitry Safonov <0x7f454c46@gmail.com> Message-ID: <59c2146d-210a-bbf9-0f2f-36e1e79688e7@gmail.com> Date: Wed, 21 Jul 2021 21:18:30 +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: <48ba72b8-3da2-e438-6148-5ec22172d475@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 9:08 PM, Dmitry Safonov wrote: > On 7/21/21 9:05 PM, Andrew Morton wrote: >> On Wed, 21 Jul 2021 14:21:54 +0100 Dmitry Safonov <0x7f454c46@gmail.com> wrote: >> >>>> Let's not do this. >>>> Account memory in mremap() fast-path for growing VMAs or in move_vma() >>>> for actually moving things. The same simpler way as it's done by >>>> vm_stat_account(), but with a difference to call >>>> security_vm_enough_memory_mm() before copying/adjusting VMA. >>>> >>>> Originally noticed by Chen Wandun: >>>> https://lkml.kernel.org/r/20210717101942.120607-1-chenwandun@huawei.com >>> >>> The patch by Chen Wandun still makes sense with this v2. >>> Heh :-) >> >> Should >> https://lkml.kernel.org/r/20210717101942.120607-1-chenwandun@huawei.com >> still be applied then? Did you ack it? >> > > Yes, please keep that patch with > Acked-by: Dmitry Safonov > > This one comes on the top to correct accounting for MREMAP_DONTUNMAP. Please, also wait for reviews for this one. I think it's correct and simplifies the complex code, but now I look into the code again, I see that: : /* : * MREMAP_DONTUNMAP is always a move and it does not allow resizing : * in the process. : */ : if (flags & MREMAP_DONTUNMAP && : (!(flags & MREMAP_MAYMOVE) || old_len != new_len)) : return ret; So, this part can be dropped: > Fixes: e346b3813067 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()") But I think the patch still makes sense. Brian, can I have your review on it? Thanks, Dmitry