From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752366AbeDEDvR (ORCPT ); Wed, 4 Apr 2018 23:51:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:55886 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751233AbeDEDvQ (ORCPT ); Wed, 4 Apr 2018 23:51:16 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0246B20838 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jaegeuk@kernel.org Date: Wed, 4 Apr 2018 20:51:15 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chao@kernel.org Subject: Re: [PATCH] f2fs: enlarge block plug coverage Message-ID: <20180405035115.GC50337@jaegeuk-macbookpro.roam.corp.google.com> References: <20180404085404.82184-1-yuchao0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180404085404.82184-1-yuchao0@huawei.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/04, Chao Yu wrote: > This patch enlarges block plug coverage in __issue_discard_cmd, in > order to collect more pending bios before issuing them, to avoid > being disturbed by previous discard I/O in IO aware discard mode. Hmm, then we need to wait for huge discard IO for over 10 secs, which will affect following read/write IOs accordingly. In order to avoid that, we actually need to limit the discard size. Thanks, > > Signed-off-by: Chao Yu > --- > fs/f2fs/segment.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 8f0b5ba46315..4287e208c040 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -1208,10 +1208,12 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi, > pend_list = &dcc->pend_list[i]; > > mutex_lock(&dcc->cmd_lock); > + > + blk_start_plug(&plug); > + > if (list_empty(pend_list)) > goto next; > f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root)); > - blk_start_plug(&plug); > list_for_each_entry_safe(dc, tmp, pend_list, list) { > f2fs_bug_on(sbi, dc->state != D_PREP); > > @@ -1227,8 +1229,9 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi, > if (++iter >= dpolicy->max_requests) > break; > } > - blk_finish_plug(&plug); > next: > + blk_finish_plug(&plug); > + > mutex_unlock(&dcc->cmd_lock); > > if (iter >= dpolicy->max_requests) > -- > 2.15.0.55.gc2ece9dc4de6