From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932129AbdEKCl2 (ORCPT ); Wed, 10 May 2017 22:41:28 -0400 Received: from mail.kernel.org ([198.145.29.136]:34236 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932071AbdEKCl1 (ORCPT ); Wed, 10 May 2017 22:41:27 -0400 Date: Wed, 10 May 2017 19:41:23 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH 1/3] f2fs: use f2fs_submit_page_bio for ra_meta_pages Message-ID: <20170511024123.GB3967@jaegeuk.local> References: <20170510234816.3373-1-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/11, Chao Yu wrote: > Hi Jaegeuk, > > On 2017/5/11 7:48, Jaegeuk Kim wrote: > > This patch avoids to use f2fs_submit_merged_bio for read, which was the only > > read case. > > This makes f2fs losing the chance to merge multiple pages into one bio during > reading continuous physical blocks, it may cause potential performance > regression, how about using a local bio in ra_meta_pages to cache more pages? This is a readahead flow, which is asynchronous and not a performance critical flow. And, I expect blk_plug is still able to merge them. We're using this in readahead of node blocks as well. Thanks, > > Thanks, > > > > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/checkpoint.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > index ea9c317b5916..8d92f8249000 100644 > > --- a/fs/f2fs/checkpoint.c > > +++ b/fs/f2fs/checkpoint.c > > @@ -207,12 +207,10 @@ int ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages, > > } > > > > fio.page = page; > > - fio.old_blkaddr = fio.new_blkaddr; > > - f2fs_submit_page_mbio(&fio); > > + f2fs_submit_page_bio(&fio); > > f2fs_put_page(page, 0); > > } > > out: > > - f2fs_submit_merged_bio(sbi, META, READ); > > blk_finish_plug(&plug); > > return blkno - start; > > } > >