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=-6.5 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 BA875C433DF for ; Thu, 20 Aug 2020 00:29:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96F8720885 for ; Thu, 20 Aug 2020 00:29:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZprFyVMz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726825AbgHTA3e (ORCPT ); Wed, 19 Aug 2020 20:29:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726609AbgHTA3d (ORCPT ); Wed, 19 Aug 2020 20:29:33 -0400 Received: from mail-ed1-x544.google.com (mail-ed1-x544.google.com [IPv6:2a00:1450:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36754C061757 for ; Wed, 19 Aug 2020 17:29:33 -0700 (PDT) Received: by mail-ed1-x544.google.com with SMTP id m20so294280eds.2 for ; Wed, 19 Aug 2020 17:29:33 -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=mYzA5fg5vLsbWiukQbExv7xlsQe0VTmH6cpyjVNlU0U=; b=ZprFyVMzXfxeJ3pUuCnzlj9BBhr2RRUYNrtuwyg3qcLreQiW1I9YuCeqJsr3FuOX+n sTZ7eB6EKBCfTbUZDFE6xu7vkn3W9dm2xrbF+2c9AjSIeYjUiY4h2LvakHAEosLB0AwF 8A6Cr+l2DN6+qCpA7wiV3TqwQ1ddWFpkn4H86ejH2Ejo+7fo9S2Nd+rRHHRRFg8ZmOkU fy/buLv4o+zG4kUqml4UA4vovD0kIxRvznwT4ZzYuTFtNBopOf5HiKaMZsLWKTGBCEXi WRFUH8vyIqQoHId5v0wcCEd+Po9AvSylE2AgYmh7kz8sRaT5dvlfTctIJtDvZ7L0H6jE uJvQ== 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=mYzA5fg5vLsbWiukQbExv7xlsQe0VTmH6cpyjVNlU0U=; b=gb/Jksl1v8zPahW0lpKfak7pinLxGsDKUs20RTNVEQJgnpSIONjmp75FzLJ1HXJ3tZ tDCmNtES4Tsoqq55HSsHjQ0iMYgHsWnL5p2AmUf35/elQXJb13UJ78Ac1BLRuFmfHZ4I ehnysQIlAZANx//fM1oAcyRvOJaL/py3AW2avdYy5ehORn0+hm1vWKcIRN8erzgXTywc zBPs/BCI0HsOp/rVOixg2pW5PbHVCOc8hNh0GRhKfh7pHRgvN4tOuENLlRezkasYQjWE x0YGEqgXlzp3kd0KmvRF66e1jrB4HDCoke1sguKg5bbfl5nn5zHNl2c9nNr0wEkoXbuF UVIg== X-Gm-Message-State: AOAM532oOo/ZIWDOverdFs5vWenF/CldGA+V04XHphSGiTICt4/xCvMj i+YYgPtB9t0OePe1tRoQzpPHQQYMGCY= X-Google-Smtp-Source: ABdhPJwdVBDh5qkPDJmyRmFhEqhN2F2EyIBUkeNcNddncrrCGy2DNAwJTg8cQ8GarxottVOKjlOLjQ== X-Received: by 2002:a05:6402:b32:: with SMTP id bo18mr547039edb.201.1597883371553; Wed, 19 Aug 2020 17:29:31 -0700 (PDT) Received: from [10.69.56.142] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id le20sm286759ejb.96.2020.08.19.17.29.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 Aug 2020 17:29:30 -0700 (PDT) Subject: Re: [PATCH v2] mm: include CMA pages in lowmem_reserve at boot To: Andrew Morton , Florian Fainelli Cc: Jason Baron , David Rientjes , "Kirill A. Shutemov" , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1597423766-27849-1-git-send-email-opendmb@gmail.com> <20200818201817.351499e75cba2a84e8bf33e6@linux-foundation.org> <20200819102214.32238093b116ab6f1c5c7b73@linux-foundation.org> <50ad53dc-faf2-3014-bac3-be370b972f59@gmail.com> <20200819104057.4b91898b76302b7b1c3e8e56@linux-foundation.org> From: Doug Berger Message-ID: <65909c25-71b2-0116-1ac7-a56118bca86e@gmail.com> Date: Wed, 19 Aug 2020 17:32:35 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200819104057.4b91898b76302b7b1c3e8e56@linux-foundation.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 On 8/19/2020 10:40 AM, Andrew Morton wrote: > On Wed, 19 Aug 2020 10:30:25 -0700 Florian Fainelli wrote: > >> On 8/19/20 10:22 AM, Andrew Morton wrote: >>> On Wed, 19 Aug 2020 10:15:53 -0700 Florian Fainelli wrote: >>> >>>>>> In many cases the difference is not significant, but for example >>>>>> an ARM platform with 1GB of memory and the following memory layout >>>>>> [ 0.000000] cma: Reserved 256 MiB at 0x0000000030000000 >>>>>> [ 0.000000] Zone ranges: >>>>>> [ 0.000000] DMA [mem 0x0000000000000000-0x000000002fffffff] >>>>>> [ 0.000000] Normal empty >>>>>> [ 0.000000] HighMem [mem 0x0000000030000000-0x000000003fffffff] >>>>>> >>>>>> would result in 0 lowmem_reserve for the DMA zone. This would allow >>>>>> userspace to deplete the DMA zone easily. >>>>> >>>>> Sounds fairly serious for thos machines. Was a cc:stable considered? >>>> >>>> Since there is a Fixes: tag, it may have been assumed that the patch >>>> would be picked up and as soon as it reaches Linus' tree it would be >>>> picked up by the stable selection. >>> >>> It doesn't work that way - sometimes a fix isn't considered important >>> enough to backport. It could just fix a typo in a comment! >> >> Then can this be applied ASAP and back ported? > > Sure. > As Florian guessed, I assumed the Fixes: tag was a sufficient clue since I wouldn't normally apply a Fixes tag to a typo correction in a comment. I suspect I have been spoiled by David Miller :). Thanks for the quick turn-around and applying the cc:stable to the mmotm, Doug