From patchwork Wed Mar 29 20:48:15 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jaegeuk Kim X-Patchwork-Id: 9652569 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3195D60349 for ; Wed, 29 Mar 2017 20:53:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 23EDC28484 for ; Wed, 29 Mar 2017 20:53:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 18EE328554; Wed, 29 Mar 2017 20:53:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C955528484 for ; Wed, 29 Mar 2017 20:53:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932813AbdC2Usp (ORCPT ); Wed, 29 Mar 2017 16:48:45 -0400 Received: from mail.kernel.org ([198.145.29.136]:42108 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932745AbdC2UsZ (ORCPT ); Wed, 29 Mar 2017 16:48:25 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1759F2024F; Wed, 29 Mar 2017 20:48:23 +0000 (UTC) Received: from localhost (107-1-141-74-ip-static.hfc.comcastbusiness.net [107.1.141.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0890520225; Wed, 29 Mar 2017 20:48:21 +0000 (UTC) From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim Subject: [PATCH 2/2] f2fs: avoid IO split due to mixed WB_SYNC_ALL and WB_SYNC_NONE Date: Wed, 29 Mar 2017 13:48:15 -0700 Message-Id: <20170329204815.9175-2-jaegeuk@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170329204815.9175-1-jaegeuk@kernel.org> References: <20170329204815.9175-1-jaegeuk@kernel.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If two threads try to flush dirty pages in different inodes respectively, f2fs_write_data_pages() will produce WRITE and WRITE_SYNC one at a time, resulting in a lot of 4KB seperated IOs. So, this patch gives higher priority to WB_SYNC_ALL IOs and gathers write IOs with a big WRITE_SYNC'ed bio. Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 15 +++++++++++++-- fs/f2fs/f2fs.h | 3 +++ fs/f2fs/super.c | 2 ++ 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 8f36080b47c4..b1cac6d85bcb 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1605,8 +1605,10 @@ static int f2fs_write_cache_pages(struct address_space *mapping, last_idx = page->index; } - if (--wbc->nr_to_write <= 0 && - wbc->sync_mode == WB_SYNC_NONE) { + /* give a priority to WB_SYNC threads */ + if ((atomic_read(&F2FS_M_SB(mapping)->wb_sync_req) || + --wbc->nr_to_write <= 0) && + wbc->sync_mode == WB_SYNC_NONE) { done = 1; break; } @@ -1662,9 +1664,18 @@ static int f2fs_write_data_pages(struct address_space *mapping, trace_f2fs_writepages(mapping->host, wbc, DATA); + /* to avoid spliting IOs due to mixed WB_SYNC_ALL and WB_SYNC_NONE */ + if (wbc->sync_mode == WB_SYNC_ALL) + atomic_inc(&sbi->wb_sync_req); + else if (atomic_read(&sbi->wb_sync_req)) + goto skip_write; + blk_start_plug(&plug); ret = f2fs_write_cache_pages(mapping, wbc); blk_finish_plug(&plug); + + if (wbc->sync_mode == WB_SYNC_ALL) + atomic_dec(&sbi->wb_sync_req); /* * if some pages were truncated, we cannot guarantee its mapping->host * to detect pending bios. diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 32d6f674c114..fd39db681226 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -888,6 +888,9 @@ struct f2fs_sb_info { /* # of allocated blocks */ struct percpu_counter alloc_valid_block_count; + /* writeback control */ + atomic_t wb_sync_req; /* count # of WB_SYNC threads */ + /* valid inode count */ struct percpu_counter total_valid_inode_count; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 2d78f3c76d18..cb65e6d0d275 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1566,6 +1566,8 @@ static void init_sb_info(struct f2fs_sb_info *sbi) for (i = 0; i < NR_COUNT_TYPE; i++) atomic_set(&sbi->nr_pages[i], 0); + atomic_set(&sbi->wb_sync_req, 0); + INIT_LIST_HEAD(&sbi->s_list); mutex_init(&sbi->umount_mutex); mutex_init(&sbi->wio_mutex[NODE]);