From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 017/128] mm: move readahead nr_pages check into read_pages Date: Mon, 01 Jun 2020 21:46:18 -0700 Message-ID: <20200602044618.p1O584vWx%akpm@linux-foundation.org> References: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:36996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725793AbgFBEqT (ORCPT ); Tue, 2 Jun 2020 00:46:19 -0400 In-Reply-To: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org 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 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); } /* _