From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 24BEB3C343F; Thu, 8 Oct 2026 07:59:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791446351; cv=none; b=S4N1TKMpcFpVW6vm02A6AwsBhCA0QFbFIejmdPzlm3CLdue2o7JJWps5M3FAzyRy/kxZVGH/aF09e7dACl89BvQ+yJC8sW7/R14WSDH0Fyu+82PoYfxQNeZqqIfd6/aaZqcrjAoRlsqUfugRhWKKqLBKIkdoaoG3+CqnoveCAE4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791446351; c=relaxed/simple; bh=qDJV4NUK9keKCwSgXigvksFKxRBTA2m8mTNRC0Bn7eg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=du31s4piuw56fVfVKTzDQ1Z5M/ZJFtttqQfDzeXYfJZgC2nOZ6JCEa83syu1ym37y7ndW6ooBpk0NXoIxPJfBILsXU8AObW7usQ1MZpAtGT3Lfd4jY8V96Kt5C/cCO0FLZICHAvaWgOJVd2Xbg57JUAC9FnNrBMy9vT7comnzOU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=fVnhGmaO; arc=none smtp.client-ip=115.124.30.133 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) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="fVnhGmaO" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1791446339; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=HcrCKp2Z/lN3tk4V8Y2aF9bTvR6+Hep4GNXCTRa+zWE=; b=fVnhGmaOL9Oz8hO+1ur5ogeXt+UlLmnY/0KWY0+xtijK+oglL14GoqDVZOHQoAoECZ5LB0L3OkDK3xT1CwtL+qJ0lsXYKktBIgql6ZboLYmlydhtjhii/gW5SG/p4kv3JQbM1Yr9Z69yCJ5p805bR5y7a5z2eEIIe1maqah+H9g= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033045133197;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=11;SR=0;TI=SMTPD_---0XCMHsUt_1791446336; Received: from 30.74.113.73(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0XCMHsUt_1791446336 cluster:ay36) by smtp.aliyun-inc.com; Thu, 08 Oct 2026 15:58:57 +0800 Message-ID: <6aa5a165-3ba6-4974-b549-fed7318ead49@linux.alibaba.com> Date: Thu, 8 Oct 2026 15:58:56 +0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [BUG] shmem: FALLOC_FL_PUNCH_HOLE vs fault-around race corrupts page cache / rss counters To: Ayush Ranjan , Pedro Falcato Cc: Hugh Dickins , Matthew Wilcox , Andrew Morton , Jan Kara , David Hildenbrand , Gregory Price , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260924061708.1645968-1-ayushr@modal.com> <20260925053027.1998394-1-ayushr@modal.com> <20260925065013.3682431-1-ayushr@modal.com> <20261003033107.1488699-1-ayushr@modal.com> From: Baolin Wang In-Reply-To: <20261003033107.1488699-1-ayushr@modal.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/3/26 11:31 AM, Ayush Ranjan wrote: > Hi all, > > Gentle ping on this. Sorry for the late reply due to my vacation. The reproducer in my previous mail [1] triggers > "Bad page cache ... still mapped when deleted" on 6.18.46 within a > couple of minutes on a 128-CPU bare-metal box, with no fork() and no > gVisor involved. > > We continue to hit this in production at low frequency, so I am happy > to test patches or collect more data if that would help. Now I can reproduce this issue on my machine with the latest mm-unstable branch, and I understand the race. I have confirmed that Andrew's patch can fix it. You can try Andrew's patch.