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spf=pass (imf11.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.110 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793106267; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gC/pRsYim10huITDmGzR2CXBohnwZSkq49YKoF5hze4=; b=WrKs2/XWsJItlf/LMIkAWdA4OhEJApvoi+I/NrACRnpRlWv5ob3wZ7hOXd534I3erMGuUY xRhPHWUq43bbmwA4LLtoy/O6jA6ro1rU4cvwSe2tn/gyX8c+5uaXeqQDxBVaY5hE8RBGWx Yjf0jDGUItyKaVk3fAzBSMoI/c+f8dE= DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1793106260; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=gC/pRsYim10huITDmGzR2CXBohnwZSkq49YKoF5hze4=; b=Syv1OBCVvxlQ3xaCIk2I8+H9FP4vQkDT+z4/6mkWV0QuUvs1V1ksuwRsW5Xahy5VgHOTXn/0avR/pHoMSDp/nzdIA4JgRipCOOQLZP0B3iVbJExdACsLlU8Qe/LZ0UYvTurnmRhzfq4uFBmKaS3MYWujcL289pUeiRdTO33i8VQ= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R761e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033032089153;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0XDdo7mv_1793106258; Received: from 30.74.144.191(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0XDdo7mv_1793106258 cluster:ay36) by smtp.aliyun-inc.com; Tue, 27 Oct 2026 21:04:19 +0800 Message-ID: <2890601a-e842-4321-94e9-673df94c97a3@linux.alibaba.com> Date: Tue, 27 Oct 2026 21:04:17 +0800 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5] mm: memory: fix truncation removing mapped folios To: "David Hildenbrand (Arm)" , akpm@linux-foundation.org Cc: ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, qi.zheng@linux.dev, jack@suse.cz, pfalcato@suse.de, ayushr@modal.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <2ba579e8-06fb-41f5-9eb2-f02b2aabe29b@kernel.org> <87e32afd-75de-4407-8f0c-fb70b40d5eca@linux.alibaba.com> <81ee2c92-f342-4f7f-aacd-d9558e67a980@kernel.org> <4880d4ff-8486-4e22-9923-bd4f2407b1cb@kernel.org> <3c73fe54-68d8-41f3-8f9f-06c4a1891e01@kernel.org> From: Baolin Wang In-Reply-To: <3c73fe54-68d8-41f3-8f9f-06c4a1891e01@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: 8B3AB40005 X-Stat-Signature: x7dcznfkk3r4eeixtpqhdqcto3n3rzbu X-Rspamd-Server: rspam01 X-Spam-Status: No, score=-14.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=4.0.1 X-HE-Tag: 1793106264-19047 X-HE-Meta: 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 Ng6ZJ88X SMd33dZZeQrpfbFwKHw8PYKs/DAXeNs/UrdQJTR0UNZYBmJOjCr2LEt7oU8J3SULoRbrGBw8I9i1n9uA3wQDJPZi1AFAHWkV0/xTHXYrUcbzgaTzFO9FeDa6QXRCl4+Qie3PW0nGQ6d7nlMH3l17oj0E9/34CgwWWKRgqvWSlwyoV5cKhb5/F7aSZ/HhYn9aaBQ01gr7hN3lLY9DtJnJGUJSSbi2IkjHzH8Nvw5HYj9RGuqvqS73nonGyw0BSsCAJOfIFAnSvXIlZNBeYLsXpchRnKB0pUozboV6xVpGyjuVOiPWh2NIFdtJ9H+5OxwsduedS Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/27/26 8:53 PM, David Hildenbrand (Arm) wrote: > On 10/27/26 13:50, Baolin Wang wrote: >> >> >> On 10/27/26 6:55 PM, David Hildenbrand (Arm) wrote: >>> On 10/27/26 11:35, Baolin Wang wrote: >>>> >>>> >>>> >>>> Sure. >>>> >>>> >>>> IMHO, I'm not a big fan of adding two pmd_none() checks just to avoid an >>>> uncommon concurrent sync. >>> >>> It's what we already had. We had to: one for handling pmd_none() directly and >>> one for handling zapping while splitting (file THPs). >>> >>> We just managed to let the second also handle the final piece of the former. >>> >>> Anyhow, let's get this fixed. >>> >>> If you think the code is clearer your way (where I disagree) >> >> Fair enough. Though I have a different taste, I'd still like to make the >> maintainer happy. > > Don't worry, it's hard to make me unhappy :) > > (just a bit overloaded right now) > >> I'll send out v6 tomorrow following your suggestion. >> > > That looks good. Thanks. > Are you planning on following up with the memory barrier > optimization for smaller folios? If I can find some time, though I have quite a few pending TODOs now :). I don't think this is urgent, so if no one else picks it up, I'll add it to my TODO list. > I hope below doesn't end up in some performance degradation. This is not a common case, so I think it's fine.