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 1414FC47090 for ; Tue, 6 Dec 2022 20:53:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 79F9D8E0003; Tue, 6 Dec 2022 15:53:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 74FDB8E0001; Tue, 6 Dec 2022 15:53:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 63EB58E0003; Tue, 6 Dec 2022 15:53:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 53F898E0001 for ; Tue, 6 Dec 2022 15:53:40 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 02683A0BB0 for ; Tue, 6 Dec 2022 20:53:39 +0000 (UTC) X-FDA: 80213082600.22.5FB8A07 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf12.hostedemail.com (Postfix) with ESMTP id 84B9D40017 for ; Tue, 6 Dec 2022 20:53:39 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=XwL9Wmse; spf=none (imf12.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1670360019; 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:dkim-signature; bh=fCWSY7cJhC6SCsB3eS/lFIy0C//ufeGGLBNh5MPIYFM=; b=M20d38s8/xvnBiBeVJsaSG2KQ6u/mo27zy2MMiHtCLupAoSwJGGJIRU9gtZH+ls9Y260Rb 7jKfD2IeKpTg9RdGa1ViF6aZ/gP/teQlYGJ+9v4wjotpap2zkFi59NkZ7bgfjvSDoJi8pv z0S0VS/OD48A9LvEj/9kYkAPOfsv6T0= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=XwL9Wmse; spf=none (imf12.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1670360019; a=rsa-sha256; cv=none; b=Bikhpd54umipmuw5yztwZ5eXXIlejB6TQOTySyU1+eh7rTYeZEkrAy28Fx7/qbxtBP5yl7 O9a5yqvf3uTAObvDn0TkMFUl+s8JEye71ntINENrIOPMKlSFd7/Cj29wNbpYmYVF8qQunE FkRmoeDfeIN5Vv25QBJEiELkhMxKJ/0= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=fCWSY7cJhC6SCsB3eS/lFIy0C//ufeGGLBNh5MPIYFM=; b=XwL9WmsevY1I4e+gKktbMIjyPZ 7YR84ru8ttEvCxmMOObqRIzHYEebEI2uAbr1/v2x99Q+EqRSvtK7uPJ8gXa/2lhfAvsZZE5DqXeFN eGU0a8U8jQ8vZtwQiI3cmQatmYx9pjDu2HrZgw1hGOtrm/kQVW0VL3I2gYMLRTl9sbjRdRtY+vAwW pixTnKryWDAJnUtGnw/bErL/18wljmeI4qBUQvjDkAuQYlEQpIsr5pwiBrrhGsKxz8PQ2lMCYifwL rjbSBuVtzxI50nVC5RHStvS7qVU0M0JSKpdGOC+6K2ONKh32AiLueU9F1lwvd4YUZ0Cyqyqlv68ev zEa3BS9A==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1p2ewj-004oCG-4Y; Tue, 06 Dec 2022 20:53:45 +0000 Date: Tue, 6 Dec 2022 20:53:45 +0000 From: Matthew Wilcox To: "Vishal Moola (Oracle)" Cc: linux-mm@kvack.org, tytso@mit.edu, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [PATCH mm-unstable] ext4: Convert mext_page_double_lock() to mext_folio_double_lock() Message-ID: References: <20221206204115.35258-1-vishal.moola@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 84B9D40017 X-Stat-Signature: o5bhk3ohif1bs7d68iwz6d1owbshh6sj X-Rspam-User: X-Spamd-Result: default: False [-3.65 / 9.00]; BAYES_HAM(-5.95)[99.90%]; SUSPICIOUS_RECIPS(1.50)[]; SUBJECT_HAS_UNDERSCORES(1.00)[]; R_DKIM_ALLOW(-0.20)[infradead.org:s=casper.20170209]; MIME_GOOD(-0.10)[text/plain]; RCVD_NO_TLS_LAST(0.10)[]; R_SPF_NA(0.00)[no SPF record]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; ARC_SIGNED(0.00)[hostedemail.com:s=arc-20220608:i=1]; RCVD_COUNT_TWO(0.00)[2]; DKIM_TRACE(0.00)[infradead.org:+]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; FROM_HAS_DN(0.00)[]; MID_RHS_MATCH_FROMTLD(0.00)[]; TO_DN_SOME(0.00)[]; DMARC_NA(0.00)[infradead.org]; TAGGED_RCPT(0.00)[]; ARC_NA(0.00)[] X-Rspamd-Server: rspam08 X-HE-Tag: 1670360019-639846 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 Tue, Dec 06, 2022 at 08:50:02PM +0000, Matthew Wilcox wrote: > > flags = memalloc_nofs_save(); > > - page[0] = grab_cache_page_write_begin(mapping[0], index1); > > - if (!page[0]) { > > + folio[0] = __filemap_get_folio(mapping[0], index1, fgp_flags, > > + mapping_gfp_mask(mapping[0])); > > one > > > + if (!folio[0]) { > > memalloc_nofs_restore(flags); > > return -ENOMEM; > > } > > > > - page[1] = grab_cache_page_write_begin(mapping[1], index2); > > + folio[1] = __filemap_get_folio(mapping[1], index2, fgp_flags, > > + mapping_gfp_mask(mapping[1])); > > two *facepalm*. Those don't contain calls to compound_head(), they contain calls to folio_file_page(), which is still a moderately-expensive unnecessary conversion, but a conversion in the other direction.