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 2E745C3F6B0 for ; Fri, 29 Jul 2022 14:11:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 53A146B0071; Fri, 29 Jul 2022 10:11:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4E7DA6B0072; Fri, 29 Jul 2022 10:11:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3D6D68E0001; Fri, 29 Jul 2022 10:11:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 2F8AA6B0071 for ; Fri, 29 Jul 2022 10:11:52 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id DA53240138 for ; Fri, 29 Jul 2022 14:11:51 +0000 (UTC) X-FDA: 79740326064.11.A5A290A Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf02.hostedemail.com (Postfix) with ESMTP id 4205E80089 for ; Fri, 29 Jul 2022 14:11:50 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 15D2868AA6; Fri, 29 Jul 2022 16:11:46 +0200 (CEST) Date: Fri, 29 Jul 2022 16:11:45 +0200 From: Christoph Hellwig To: Mel Gorman Cc: Jan Kara , Christoph Hellwig , Bob Peterson , Andreas Gruenbacher , "Darrick J. Wong" , Damien Le Moal , Naohiro Aota , Johannes Weiner , Vlastimil Babka , Johannes Thumshirn , cluster-devel@redhat.com, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: remove iomap_writepage v2 Message-ID: <20220729141145.GA31605@lst.de> References: <20220719041311.709250-1-hch@lst.de> <20220728111016.uwbaywprzkzne7ib@quack3> <20220729092216.GE3493@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220729092216.GE3493@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659103910; a=rsa-sha256; cv=none; b=d2Sw8C3+6yB33wt8ytamvKgvNeyInvY9uWgFmT2WUjLiuLxsG/eyKV1hR6scAoK/xtald6 dGJB63bOlXOONNx6fRA2+KFrr0CxqXpQtXQUkCz5B0zAXxyq1Q9VxbmbTYl+6XwUlrkxVr zhpfOKEPOemh5WMTHYArXWYP6FG8kGc= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=none; dmarc=none; spf=none (imf02.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659103910; 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: in-reply-to:in-reply-to:references:references; bh=5JvxEjjjwGvERweBKNt8uQ/MS7Ngeidl+zqfM8v4vhQ=; b=Ce3OjjN/ymJ/gyye5B0TpaUhzyqy2z1dv2rF4lvfjdg9GN//u0DDYEW56D5tQGyFIbw9VC N2EpM/oswYy0zKHZ1/Nd7WWqFEByijrkSG/6ktAc/TgE+NwHK7bKXNslU9l6HGUqD4/qE2 9s0A3PGhnfHAgo9s5q/zD9YditUyOF8= X-Rspamd-Queue-Id: 4205E80089 X-Rspam-User: X-Stat-Signature: 5499zy79efpbwnw1a8tm8ny9fgsroaz3 Authentication-Results: imf02.hostedemail.com; dkim=none; dmarc=none; spf=none (imf02.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de X-Rspamd-Server: rspam08 X-HE-Tag: 1659103910-371544 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 Fri, Jul 29, 2022 at 10:22:16AM +0100, Mel Gorman wrote: > There is some context missing because it's not clear what the full impact is > but it is definitly the case that writepage is ignored in some contexts for > common filesystems so lets assume that writepage from reclaim context always > failed as a worst case scenario. Certainly this type of change is something > linux-mm needs to be aware of because we've been blind-sided before. Between willy and Johannes pushing or it I was under the strong assumption that linux-mm knows of it.. > I don't think it would be incredibly damaging although there *might* be > issues with small systems or cgroups. Johannes specifically mentioned that cgroup writeback will never call into ->writepage anyway.