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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48C71C6FA8F for ; Wed, 30 Aug 2023 06:12:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2AB038E0043; Wed, 30 Aug 2023 02:12:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 25ACD8E0009; Wed, 30 Aug 2023 02:12:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1495D8E0043; Wed, 30 Aug 2023 02:12:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 02A508E0009 for ; Wed, 30 Aug 2023 02:12:04 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id C53E01401E5 for ; Wed, 30 Aug 2023 06:12:04 +0000 (UTC) X-FDA: 81179750568.13.9948A1F Received: from out-248.mta0.migadu.com (out-248.mta0.migadu.com [91.218.175.248]) by imf13.hostedemail.com (Postfix) with ESMTP id 8D9212001F for ; Wed, 30 Aug 2023 06:12:01 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=n8qZNKHD; spf=pass (imf13.hostedemail.com: domain of hao.xu@linux.dev designates 91.218.175.248 as permitted sender) smtp.mailfrom=hao.xu@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693375921; 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=JMzOvVHk770qYz+7D4bRM3eiaC0WBb12Z/fuZleaQ2g=; b=Hpbdk7tZUaj43jehfWh8Vdcse+uU/8lPphDxEYrMxftCmUAZzfThuO/fbZjxlJQpQdQqfB QceHlQTQxNyESE3WHlBhWM1m9LP5XEn83vghxaqMbg//NLo7ZiUfsiEKx9/FAzZD6IWysP YyZoftbibpJXsBlo+a5G51NZHaFoQN8= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=n8qZNKHD; spf=pass (imf13.hostedemail.com: domain of hao.xu@linux.dev designates 91.218.175.248 as permitted sender) smtp.mailfrom=hao.xu@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693375921; a=rsa-sha256; cv=none; b=uKo2ZSIco7ZA0oTbL9uvUg9AiBmr6A1TAtX6jFzh/mAbDBSWohtVTKdeGA6BswLzzOv/EJ RmiY6wiC0NIG9iW8PF3E7gF2v+vNmAoDhNFNc8q/ZP2McGh7/nEBwZTOJ5jEdL3X40HKmc sdnPCQqhODO63R/h9gBoEtKiPXjGnjw= Message-ID: <642de4e6-801d-fcad-a7ce-bfc6dec3b6e5@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1693375918; h=from:from: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; bh=JMzOvVHk770qYz+7D4bRM3eiaC0WBb12Z/fuZleaQ2g=; b=n8qZNKHDJ8ZkQN8s6YCFhUc5vlrIehXvAzssrfT4lOFAEgM70y7j9ccF+kTN544/il9mhv /Qwyv0zoAHdwAPeCdmanHqcxV7A/7XcL4G5u9c/o5+tWUqR2xZIKUSlHotdEAwwwHhjWvg KLK2CGyPGmGk32bcLUct3rbhOUMJhk8= Date: Wed, 30 Aug 2023 14:11:31 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 07/11] vfs: add nowait parameter for file_accessed() Content-Language: en-US To: Matthew Wilcox Cc: io-uring@vger.kernel.org, Jens Axboe , Dominique Martinet , Pavel Begunkov , Christian Brauner , Alexander Viro , Stefan Roesch , Clay Harris , Dave Chinner , "Darrick J . Wong" , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-cachefs@redhat.com, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-unionfs@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org, codalist@coda.cs.cmu.edu, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, devel@lists.orangefs.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-mtd@lists.infradead.org, Wanpeng Li References: <20230827132835.1373581-1-hao.xu@linux.dev> <20230827132835.1373581-8-hao.xu@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Hao Xu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 8D9212001F X-Rspam-User: X-Stat-Signature: 9xapmqiagw3hxz54wnxwchf39n6569sc X-Rspamd-Server: rspam01 X-HE-Tag: 1693375921-963100 X-HE-Meta: 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 xDix7Pup BV3EFTlZR5qVx/dccMWr2xE8+Qc/uSzcVtq6ZoqTSWqom6h+r54TQBSSCsIlipYm93lwrkXa9mTjolYXuMxMgMM0vTjqHjhW3WyyG440u4XsSbV1EXEA4ZVhfeH/cMLUoGO6Ma0q8VTr63BTpx9uvi+4+nVtAgeCtoaFt1aNWoD0YGickxfD/F/ek02KfJq5kVQ8pkH3GozTPHDcQLu7eEzDxtyUromUgxyTHYmerIPqryTkrNOjX89ocHtUyj7ivun4/BAhOUUxM6ocwCi/zKrmBPohqwzwv3eFoMl6HgfCG8Ylyagy6sspQLQhK6a/F0kGLLTizxAzwDEipjs1So99YqRHAgZUgwuAa X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 8/29/23 19:53, Matthew Wilcox wrote: > On Tue, Aug 29, 2023 at 03:46:13PM +0800, Hao Xu wrote: >> On 8/28/23 05:32, Matthew Wilcox wrote: >>> On Sun, Aug 27, 2023 at 09:28:31PM +0800, Hao Xu wrote: >>>> From: Hao Xu >>>> >>>> Add a boolean parameter for file_accessed() to support nowait semantics. >>>> Currently it is true only with io_uring as its initial caller. >>> >>> So why do we need to do this as part of this series? Apparently it >>> hasn't caused any problems for filemap_read(). >>> >> >> We need this parameter to indicate if nowait semantics should be enforced in >> touch_atime(), There are locks and maybe IOs in it. > > That's not my point. We currently call file_accessed() and > touch_atime() for nowait reads and nowait writes. You haven't done > anything to fix those. > > I suspect you can trim this patchset down significantly by avoiding > fixing the file_accessed() problem. And then come back with a later > patchset that fixes it for all nowait i/o. Or do a separate prep series I'm ok to do that. > first that fixes it for the existing nowait users, and then a second > series to do all the directory stuff. > > I'd do the first thing. Just ignore the problem. Directory atime > updates cause I/O so rarely that you can afford to ignore it. Almost > everyone uses relatime or nodiratime. Hi Matthew, The previous discussion shows this does cause issues in real producations: https://lore.kernel.org/io-uring/2785f009-2ebb-028d-8250-d5f3a30510f0@gmail.com/#:~:text=fwiw%2C%20we%27ve%20just%20recently%20had%20similar%20problems%20with%20io_uring%20read/write