From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=115.124.30.131 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793933356; b=c9gaW9cuKtpSepsxZ96iCUybERkTTvskL3G0/qqExnb38LYeFur78rPEh3XgjCR6xM87 Y1GABVeW6Gys4Q4fZojc2QOs6nv0W6FWN2axc/rFAdm4Hg78Eus1n9I/z7VtOALr8PZdJ BCW3KY11q7aod7o7gPbt0Sy8pFR8zEdlBQZKc7/PCoC95kt6pEefotKQf9hQfOyGlDxwP 1nLe8ToNUAsc9OTD4B0G/u0oMDmmS6iftZgqF0JTmqWwMPwMl4ZwXOg4kd2le9uQkzK3T 1LJgvLH2CEcjFYGV7JdPwB139mae6gVkKbM3XlQBb0zf00aXTRyGDIXfm0mg0Ivdzrw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793933356; h=DMARC-Filter:DKIM-Signature:X-Alimail-AntiSpam:Received:Message-ID: Date:MIME-Version:User-Agent:Subject:To:Cc:References:From: In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=MhQ3c2PQxxIs273fLfDsJaAlMJ7k+j2UNp/PTN7YehA=; b=vnesSp0KsAyCa9oGQy5yFRyAg8yW7VdXfSoou7w7FnJiHOzgRgshQcOtKqa4Uqfko4nw A5tU6d/2P579PkesL2HdVq2aZjnFeniL4k9HSrRcrgrg4cJMV1s3lbbay0Qg5JG1c463K FE98FaH4waiGCsXJ606Ms9sck/ZE0f3xHEyWPMGEy3HLU1ZTIXPENHRt4n8hfQj/06tCU GeMPB3M7Qp883JrVUFZLm9kV8zsj6RdMmkmJfVmpz4BljJvzYQySjONUxUn0u9Xi+a4qN Z+Bb8TeWYOzhgBqPGrsW8IKmeNzTNk/avkRdsUOXjrRsWoXSoMesQnOLem77ZcUOsNg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=QYzRZBdU; arc=none smtp.remote-ip=115.124.30.131 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66DDB606A332; Fri, 6 Nov 2026 02:49:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 66DDB606A332 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=QYzRZBdU DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1793933351; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=MhQ3c2PQxxIs273fLfDsJaAlMJ7k+j2UNp/PTN7YehA=; b=QYzRZBdUo4vmbD7D7WIAm31Q9xSnwQWALKdD0Gd9MBP9iKxK8o4/etn4td7zq3R70RZ5Y4+VBvgKiC6NEsEtCMceEyAgBY4+KybTf/GySPmCje2gJQUxhGoUFvEJ7xzgPvhqWKDCDA5Dk7vlxtKX6D5F5rFdxD2OJbtLQjeyhLk= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R131e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037033178;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0XEAEjFl_1793933349; Received: from 30.74.144.130(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0XEAEjFl_1793933349 cluster:ay36) by smtp.aliyun-inc.com; Fri, 06 Nov 2026 10:49:10 +0800 Message-ID: Date: Fri, 6 Nov 2026 10:49:09 +0800 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/khugepaged: don't map folios that are not uptodate in MADV_COLLAPSE To: "David Hildenbrand (Arm)" , Andrew Morton , Zi Yan , Hugh Dickins , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Zach O'Keefe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chris Mason , stable@vger.kernel.org References: <20261105-set_huge_pmd_uptodate-v1-1-a78d8a1b7117@kernel.org> From: Baolin Wang In-Reply-To: <20261105-set_huge_pmd_uptodate-v1-1-a78d8a1b7117@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/6/26 2:16 AM, David Hildenbrand (Arm) wrote: > madvise(MADV_COLLAPSE) can map PMD-sized pagecache folios that are not > uptodate. For example, shmem fallocate() can put such folios into the > page cache. > > collapse_file() already refuses to proceed with folios that are not > uptodate. Let's just do the same in try_collapse_pte_mapped_thp() and skip > such folios, leaving handling to the page faults. > > Note that collapse_file() effectively clears shmem folios through > shmem_get_folio(); let's keep this fix simple and simply let the page > fault path deal with that. > > Fixes: 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") > Reported-by: Chris Mason > Cc: stable@vger.kernel.org > Signed-off-by: David Hildenbrand (Arm) > --- Make sense to me. Reviewed-by: Baolin Wang