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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 B7A0DC46464 for ; Mon, 13 Aug 2018 02:28:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 708832177D for ; Mon, 13 Aug 2018 02:28:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 708832177D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726345AbeHMFAO (ORCPT ); Mon, 13 Aug 2018 01:00:14 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:10660 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725787AbeHMFAO (ORCPT ); Mon, 13 Aug 2018 01:00:14 -0400 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id B2F175695375A; Mon, 13 Aug 2018 10:20:05 +0800 (CST) Received: from [127.0.0.1] (10.134.22.195) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.399.0; Mon, 13 Aug 2018 10:20:04 +0800 Subject: Re: [f2fs-dev] [PATCH v3] f2fs: fix performance issue observed with multi-thread sequential read To: Jaegeuk Kim , , References: <20180810023758.46974-1-jaegeuk@kernel.org> <20180810024859.GA48219@jaegeuk-macbookpro.roam.corp.google.com> <20180810185640.GA63079@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: <57149b77-3576-87ed-2cae-a3bc2e8088f2@huawei.com> Date: Mon, 13 Aug 2018 10:20:04 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180810185640.GA63079@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jaegeuk, On 2018/8/11 2:56, Jaegeuk Kim wrote: > This reverts the commit - "b93f771 - f2fs: remove writepages lock" > to fix the drop in sequential read throughput. > > Test: ./tiotest -t 32 -d /data/tio_tmp -f 32 -b 524288 -k 1 -k 3 -L > device: UFS > > Before - > read throughput: 185 MB/s > total read requests: 85177 (of these ~80000 are 4KB size requests). > total write requests: 2546 (of these ~2208 requests are written in 512KB). > > After - > read throughput: 758 MB/s > total read requests: 2417 (of these ~2042 are 512KB reads). > total write requests: 2701 (of these ~2034 requests are written in 512KB). IMO, it only impact sequential read performance in a large file which may be fragmented during multi-thread writing. In android environment, mostly, the large file should be cold type, such as apk, mp3, rmvb, jpeg..., so I think we only need to serialize writepages() for cold data area writer. So how about adding a mount option to serialize writepage() for different type of log, e.g. in android, using serialize=4; by default, using serialize=7 HOT_DATA 1 WARM_DATA 2 COLD_DATA 4 Thanks, > > Signed-off-by: Sahitya Tummala > Signed-off-by: Jaegeuk Kim > --- > Changelog from v2: > - fix deadlock in f2fs_gc > > fs/f2fs/data.c | 9 +++++++++ > fs/f2fs/f2fs.h | 1 + > fs/f2fs/super.c | 1 + > 3 files changed, 11 insertions(+) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 45f043ee48bd..9f0149cdeed8 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2132,6 +2132,7 @@ static int __f2fs_write_data_pages(struct address_space *mapping, > struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > struct blk_plug plug; > int ret; > + bool locked = false; > > /* deal with chardevs and other special file */ > if (!mapping->a_ops->writepage) > @@ -2162,10 +2163,18 @@ static int __f2fs_write_data_pages(struct address_space *mapping, > else if (atomic_read(&sbi->wb_sync_req[DATA])) > goto skip_write; > > + if (!S_ISDIR(inode->i_mode)) { > + mutex_lock(&sbi->writepages); > + locked = true; > + } > + > blk_start_plug(&plug); > ret = f2fs_write_cache_pages(mapping, wbc, io_type); > blk_finish_plug(&plug); > > + if (locked) > + mutex_unlock(&sbi->writepages); > + > if (wbc->sync_mode == WB_SYNC_ALL) > atomic_dec(&sbi->wb_sync_req[DATA]); > /* > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index b1c127d8383b..29bbc55cbc0b 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -1133,6 +1133,7 @@ struct f2fs_sb_info { > struct rw_semaphore sb_lock; /* lock for raw super block */ > int valid_super_block; /* valid super block no */ > unsigned long s_flag; /* flags for sbi */ > + struct mutex writepages; /* mutex for writepages() */ > > #ifdef CONFIG_BLK_DEV_ZONED > unsigned int blocks_per_blkz; /* F2FS blocks per zone */ > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index be41dbd7b261..53d70b64fea1 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -2842,6 +2842,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) > /* init f2fs-specific super block info */ > sbi->valid_super_block = valid_super_block; > mutex_init(&sbi->gc_mutex); > + mutex_init(&sbi->writepages); > mutex_init(&sbi->cp_mutex); > init_rwsem(&sbi->node_write); > init_rwsem(&sbi->node_change); >