From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-110.freemail.mail.aliyun.com (out30-110.freemail.mail.aliyun.com [115.124.30.110]) (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 2F7C68479; Sun, 23 Nov 2025 01:23:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.110 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763861019; cv=none; b=DVN45hKikqG1KSxFquiUM+fp9eI3tSDHtp6KpwTakVxXeYBadan3GZd3FFbfcFMlwRF7yx2aAqGw36SUFlxkHPUaFeqlvMBE3Stk9HV2OAGTekhaND2B5JcQk9d6+BhQ8lxstUy2WKjh5Znzk9XPKpkPqr/QsZEXNnWDvmytxzc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763861019; c=relaxed/simple; bh=xeeOy9Y9AfZHjdQ419M8o1x6xYIid00dkdAZDe44HXo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Q5JOi1rqhMooziS3zGXQoqceGmrGtHdjfsnsgGXAvwIHUbz5BxSTH63zvYlqFE+B10f40QO/G8MgZ7QzuX4XjAP/NoQwezislGOGjKcO0qGaxjHQMGZQLg0eNFr2l6aUKe2ZabqNPLOk/S2NOLrxVS8jriusMuLfpuITOUg7Fgw= 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=iq7nSKs/; arc=none smtp.client-ip=115.124.30.110 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="iq7nSKs/" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1763861013; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=VCIF5DLiQMx6oN9DUx9P7XFgjwtiupQtB75jei15lO8=; b=iq7nSKs/oouky7FRG2MwTRD41R0/nCUFP8w5WyTRhRfU9V1d6ro26yPJvGwVIGUS30x6C2Kbwl/hVrbr7bl9gv67nYgrjR6YGvktq7QbXP4dPsBF0YNl4JvzuKJqyzfFGE6scbAXFY8J96zm2PdKRozmnpIem+15Iltez2KO0bo= Received: from 30.170.82.147(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0Wt66DMu_1763861012 cluster:ay36) by smtp.aliyun-inc.com; Sun, 23 Nov 2025 09:23:33 +0800 Message-ID: Date: Sun, 23 Nov 2025 09:23:31 +0800 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCHv5 0/6] zram: introduce writeback bio batching To: Sergey Senozhatsky Cc: Yuwen Chen , akpm@linux-foundation.org, bgeffon@google.com, licayy@outlook.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, minchan@kernel.org, richardycc@google.com References: <8c596737-95c1-4274-9834-1fe06558b431@linux.alibaba.com> <853796e3-fd44-4fc2-8fd2-5810342a6ebe@linux.alibaba.com> <2c6906d1-132e-401f-830f-ae771fe836c5@linux.alibaba.com> From: Gao Xiang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025/11/23 08:08, Sergey Senozhatsky wrote: > On (25/11/22 22:09), Gao Xiang wrote: >>> I thought you were talking about the backing device being >>> ext4/btrfs. Sorry, I don't have enough context/knowledge >>> to understand what you're getting at. zram has been doing >>> writeback for ages, I really don't know what you mean by >>> "to act like this". >> >> I mean, if zram is formatted as ext4, and then mount it; >> and then there is a backing file which is also in another >> ext4, you'd need a workqueue to do writeback I/Os (or needs >> a loop device to transit), was that the original question >> raised by Yuwen? > > We take pages of data from zram0 and write them straight to > the backing device. Those writes don't go through vfs/fs so > fs on the backing device will simply be corrupted, as far as > I can tell. This is not intendant use case for zram writeback. I'm pretty sure you don't understand what I meant. I won't reply this anymore, good luck. Thanks, Gao Xiang