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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=no 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 43266C63697 for ; Sat, 14 Nov 2020 18:50:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CFA2022252 for ; Sat, 14 Nov 2020 18:50:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="pMGPmxFh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CFA2022252 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 0DC496B0071; Sat, 14 Nov 2020 13:50:42 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 014E16B0072; Sat, 14 Nov 2020 13:50:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E6AA46B0073; Sat, 14 Nov 2020 13:50:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0123.hostedemail.com [216.40.44.123]) by kanga.kvack.org (Postfix) with ESMTP id ADD096B0071 for ; Sat, 14 Nov 2020 13:50:41 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 55E733625 for ; Sat, 14 Nov 2020 18:50:41 +0000 (UTC) X-FDA: 77483915082.28.camp38_1f0fed627319 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id 3C0AA6C0A for ; Sat, 14 Nov 2020 18:50:41 +0000 (UTC) X-HE-Tag: camp38_1f0fed627319 X-Filterd-Recvd-Size: 3104 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Sat, 14 Nov 2020 18:50:40 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 94B8822265; Sat, 14 Nov 2020 18:50:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605379839; bh=ezxCtaDdeZly+HW5p2b/mg5LVu5bhTfJ9fCs92Y0UZs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pMGPmxFhw48ZKVu31kEXodS5VuJ7nCpP4JNdw9xkZL/c9XuTr3psNSp6hB3uNyIlJ iQPO2Mnr7oTo4iz0n1aGaD1DJD94PouMgkwSM/4LpnoXGKC/FmQHOBGVwAHRrq7c9q xUW1RZPxRZYBOXqrkVFIYyNhWLIG0s5Qi/ipcqPo= Date: Sat, 14 Nov 2020 10:50:39 -0800 From: Andrew Morton To: Hui Su Cc: hughd@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, pankaj.gupta.linux@gmail.com, lkp@intel.com Subject: Re: [PATCH v2] mm/shmem.c: make shmem_mapping() inline Message-Id: <20201114105039.4d44e3036e22e10c9a70912c@linux-foundation.org> In-Reply-To: <20201114055134.GA186011@rlk> References: <20201114055134.GA186011@rlk> 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-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 Sat, 14 Nov 2020 13:51:34 +0800 Hui Su wrote: > inline the shmem_mapping(), and use shmem_mapping() > instead of 'inode->i_mapping->a_ops == &shmem_aops' > in shmem_evict_inode(). > > ... > > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1152,7 +1152,7 @@ static void shmem_evict_inode(struct inode *inode) > struct shmem_inode_info *info = SHMEM_I(inode); > struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); > > - if (inode->i_mapping->a_ops == &shmem_aops) { > + if (shmem_mapping(inode->i_mapping)) { > shmem_unacct_size(info->flags, inode->i_size); > inode->i_size = 0; > shmem_truncate_range(inode, 0, (loff_t)-1); > @@ -2352,7 +2352,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode > return inode; > } > > -bool shmem_mapping(struct address_space *mapping) > +inline bool shmem_mapping(struct address_space *mapping) > { > return mapping->a_ops == &shmem_aops; > } huh. I'd have expected the inlining in shmem_evict_inode() to not work because the compiler hasn't seen the definition yet. But gcc has evidently become smarter about that. But really, shmem_mapping() isn't worth an out-of-line call from any callsite - it would be best to make it inlined everywhere. - make shmem_aops global - declare shmem_aops in shmem_fs.h - export shmem_aops to modules for drivers/dma-buf/udmabuf.c - include linux/fs.h in shmem_fs.h for address_space_operations (we already include fs.h via swap.h, but we shouldn't depend on that) - make shmem_mapping() a static inline in shmem_fs.h.