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 X-Spam-Level: X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81693C48BE5 for ; Thu, 17 Jun 2021 01:30:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1918C613E2 for ; Thu, 17 Jun 2021 01:30:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1918C613E2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 745746B0070; Wed, 16 Jun 2021 21:30:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 71A876B0071; Wed, 16 Jun 2021 21:30:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 60A216B0072; Wed, 16 Jun 2021 21:30:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0044.hostedemail.com [216.40.44.44]) by kanga.kvack.org (Postfix) with ESMTP id 2F5D46B0070 for ; Wed, 16 Jun 2021 21:30:46 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D06DE10FC5 for ; Thu, 17 Jun 2021 01:30:45 +0000 (UTC) X-FDA: 78261486450.22.8491E3C Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf04.hostedemail.com (Postfix) with ESMTP id B0BC63C3 for ; Thu, 17 Jun 2021 01:30:38 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 2E114613DE; Thu, 17 Jun 2021 01:30:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1623893444; bh=W0OF5R3t53yx4zub1670pkWGrC9nfpb1vIKuqiJaCh4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=w6VhJc4sSRYSgeu7Evu4pcjgqmgza4fFFpEAocIgswoG/i8H03pH+4tUPcm1QA6zY TUqV4M4q0XnpDTXsL3EEumxGeqMPeY40D7SQdUVHkuhZrzR3Ztoo0JosUiL+N5YCJW wbaJJwVAMhkcLHeBqab6NfnoBqK1quFSsuEycK4s= Date: Wed, 16 Jun 2021 18:30:43 -0700 From: Andrew Morton To: Johannes Weiner Cc: Dave Chinner , Roman Gushchin , Tejun Heo , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 4/4] vfs: keep inodes with page cache off the inode shrinker LRU Message-Id: <20210616183043.cdd36c5ca6bee8614c609a90@linux-foundation.org> In-Reply-To: References: <20210614211904.14420-1-hannes@cmpxchg.org> <20210614211904.14420-4-hannes@cmpxchg.org> <20210615062640.GD2419729@dread.disaster.area> <20210616012008.GE2419729@dread.disaster.area> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: B0BC63C3 X-Stat-Signature: jkgexpitbbw9yywr49bspj96eqoyjxdx Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=w6VhJc4s; dmarc=none; spf=pass (imf04.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-HE-Tag: 1623893438-310997 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 Wed, 16 Jun 2021 00:54:15 -0400 Johannes Weiner wrote: > On Wed, Jun 16, 2021 at 11:20:08AM +1000, Dave Chinner wrote: > > On Tue, Jun 15, 2021 at 02:50:09PM -0400, Johannes Weiner wrote: > > > On Tue, Jun 15, 2021 at 04:26:40PM +1000, Dave Chinner wrote: > > > > On Mon, Jun 14, 2021 at 05:19:04PM -0400, Johannes Weiner wrote: > > > > > @@ -1123,6 +1125,9 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, > > > > > shadow = workingset_eviction(page, target_memcg); > > > > > __delete_from_page_cache(page, shadow); > > > > > xa_unlock_irq(&mapping->i_pages); > > > > > + if (mapping_shrinkable(mapping)) > > > > > + inode_add_lru(mapping->host); > > > > > + spin_unlock(&mapping->host->i_lock); > > > > > > > > > > > > > No. Inode locks have absolutely no place serialising core vmscan > > > > algorithms. > > > > > > What if, and hear me out on this one, core vmscan algorithms change > > > the state of the inode? > > > > Then the core vmscan algorithm has a layering violation. > > You're just playing a word game here. Don't think so. David is quite correct in saying that vmscan shouldn't mess with inode state unless it's via address_space_operations?