From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754401AbdEKDWg (ORCPT ); Wed, 10 May 2017 23:22:36 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:5871 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753226AbdEKDWf (ORCPT ); Wed, 10 May 2017 23:22:35 -0400 Subject: Re: [f2fs-dev] [PATCH 1/3] f2fs: use f2fs_submit_page_bio for ra_meta_pages To: Jaegeuk Kim References: <20170510234816.3373-1-jaegeuk@kernel.org> <20170511024123.GB3967@jaegeuk.local> CC: , , From: Chao Yu Message-ID: <2e1c8d7b-4494-29c3-1f6b-e181f2e312a5@huawei.com> Date: Thu, 11 May 2017 11:22:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <20170511024123.GB3967@jaegeuk.local> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.5913D8F3.009E,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 0191da2184fe676326a3e7cf0fb4714c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/5/11 10:41, Jaegeuk Kim wrote: > 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. Confirmed, block plug can do the merge. :) Thanks, > > 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; >>> } >>> > > . >