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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 7A068C433E0 for ; Tue, 2 Jun 2020 04:46:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3E57420734 for ; Tue, 2 Jun 2020 04:46:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="A2asXgvE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E57420734 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 D535980015; Tue, 2 Jun 2020 00:46:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D2A3B80007; Tue, 2 Jun 2020 00:46:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C3FE580015; Tue, 2 Jun 2020 00:46:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0242.hostedemail.com [216.40.44.242]) by kanga.kvack.org (Postfix) with ESMTP id A7F8D80007 for ; Tue, 2 Jun 2020 00:46:20 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 6DCD3180AD804 for ; Tue, 2 Jun 2020 04:46:20 +0000 (UTC) X-FDA: 76883035320.17.cent73_1a3631642a03e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id 55771180D0180 for ; Tue, 2 Jun 2020 04:46:20 +0000 (UTC) X-HE-Tag: cent73_1a3631642a03e X-Filterd-Recvd-Size: 4024 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Tue, 2 Jun 2020 04:46:19 +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 A3ADD20772; Tue, 2 Jun 2020 04:46:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591073179; bh=t/WjuE3ucXS1DdNaIO/FQIXG3l7RX5IwwyiZ509d43g=; h=Date:From:To:Subject:In-Reply-To:From; b=A2asXgvEW5xWPCtvAODjrizDF+BQQJ/5tvjQjzjZsGq04XuFCVwecI49u0WnDqV8K pmM5bvXdpTRf8hcQUVwvLWq8KYB95ujqD92KEkGFKYx/URX4KRDvIQlyRbmldYyNo7 dwFQpN6mkcnBTrqYKyQZu0Jf1yyz2DfKZEVk1UlM= Date: Mon, 01 Jun 2020 21:46:18 -0700 From: Andrew Morton To: akpm@linux-foundation.org, darrick.wong@oracle.com, dchinner@redhat.com, ebiggers@google.com, gaoxiang25@huawei.com, hch@lst.de, jaegeuk@kernel.org, jhubbard@nvidia.com, johannes.thumshirn@wdc.com, joseph.qi@linux.alibaba.com, junxiao.bi@oracle.com, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, mszeredi@redhat.com, torvalds@linux-foundation.org, william.kucharski@oracle.com, willy@infradead.org, xiyou.wangcong@gmail.com, yuchao0@huawei.com, ziy@nvidia.com Subject: [patch 017/128] mm: move readahead nr_pages check into read_pages Message-ID: <20200602044618.p1O584vWx%akpm@linux-foundation.org> In-Reply-To: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 55771180D0180 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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: From: "Matthew Wilcox (Oracle)" Subject: mm: move readahead nr_pages check into read_pages Simplify the callers by moving the check for nr_pages and the BUG_ON into read_pages(). Link: http://lkml.kernel.org/r/20200414150233.24495-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Zi Yan Reviewed-by: John Hubbard Reviewed-by: Christoph Hellwig Reviewed-by: William Kucharski Reviewed-by: Johannes Thumshirn Cc: Chao Yu Cc: Cong Wang Cc: Darrick J. Wong Cc: Dave Chinner Cc: Eric Biggers Cc: Gao Xiang Cc: Jaegeuk Kim Cc: Joseph Qi Cc: Junxiao Bi Cc: Michal Hocko Cc: Miklos Szeredi Signed-off-by: Andrew Morton --- mm/readahead.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/mm/readahead.c~mm-move-readahead-nr_pages-check-into-read_pages +++ a/mm/readahead.c @@ -119,6 +119,9 @@ static void read_pages(struct address_sp struct blk_plug plug; unsigned page_idx; + if (!nr_pages) + return; + blk_start_plug(&plug); if (mapping->a_ops->readpages) { @@ -138,6 +141,8 @@ static void read_pages(struct address_sp out: blk_finish_plug(&plug); + + BUG_ON(!list_empty(pages)); } /* @@ -180,8 +185,7 @@ void __do_page_cache_readahead(struct ad * contiguous pages before continuing with the next * batch. */ - if (nr_pages) - read_pages(mapping, filp, &page_pool, nr_pages, + read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask); nr_pages = 0; continue; @@ -202,9 +206,7 @@ void __do_page_cache_readahead(struct ad * uptodate then the caller will launch readpage again, and * will then handle the error. */ - if (nr_pages) - read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask); - BUG_ON(!list_empty(&page_pool)); + read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask); } /* _