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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED, USER_AGENT_MUTT 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 BE4E8C6778F for ; Sat, 7 Jul 2018 01:08:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6271B2254D for ; Sat, 7 Jul 2018 01:08:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Hh4GI0cs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6271B2254D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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 S933174AbeGGBIk (ORCPT ); Fri, 6 Jul 2018 21:08:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:33028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933125AbeGGBIg (ORCPT ); Fri, 6 Jul 2018 21:08:36 -0400 Received: from localhost (unknown [104.132.1.88]) (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 A67812254D; Sat, 7 Jul 2018 01:08:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1530925715; bh=PT/8ZGpniCvCnGS0jl38ihzL52KH1dG19QDt+3UdQQc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Hh4GI0cs3C+pj7IzJYWCcaczEoRt1YV7mRTTTFM/Ge2jdHIz0FnYvRvRfwcqVJ+8D oE43TnMjYRVlGpJ50Bf6EaT3mP9Yi4+CSV0/2WonhZkJWnNcfCpPy23ISIkx1whFA0 vWI/v7Mh1C7cZDZa52+6Sl6dgnu0C+hd/1d6eeJ4= Date: Fri, 6 Jul 2018 18:08:34 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu Subject: Re: [PATCH] f2fs: split discard command in prior to block layer Message-ID: <20180707010834.GA3767@jaegeuk-macbookpro.roam.corp.google.com> References: <20180704153746.2510-1-chao@kernel.org> <20180706224533.GC77984@jaegeuk-macbookpro.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/07, Chao Yu wrote: > Hi Jaegeuk, > > On 2018/7/7 6:45, Jaegeuk Kim wrote: > > On 07/04, Chao Yu wrote: > >> From: Chao Yu > >> > >> Some devices has small max_{hw,}discard_sectors, so that in > >> __blkdev_issue_discard(), one big size discard bio can be split > >> into multiple small size discard bios, result in heavy load in IO > >> scheduler and device, which can hang other sync IO for long time. > >> > >> Now, f2fs is trying to control discard commands more elaboratively, > >> in order to make less conflict in between discard IO and user IO > >> to enhance application's performance, so in this patch, we will > >> split discard bio in f2fs in prior to in block layer to reduce > >> issuing multiple discard bios in a short time. > > > > Hi Chao, > > > > In terms of # of candidates, can we control this when actually issuing > > the discard commands? > > IIUC, you mean once we pick one discard entry in rbtree, if > max_{hw,}discard_sectors is smaller than size of this discard, then we can split > it into smaller ones by discard_sectors, and just issue one or partials of them? Yes, sort of. > > Thanks, > > > > > Thanks, > > > >> > >> Signed-off-by: Chao Yu > >> --- > >> fs/f2fs/f2fs.h | 13 ++++++------- > >> fs/f2fs/segment.c | 25 ++++++++++++++++++++++--- > >> 2 files changed, 28 insertions(+), 10 deletions(-) > >> > >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > >> index a9da5a089cb4..a09d2b2d9520 100644 > >> --- a/fs/f2fs/f2fs.h > >> +++ b/fs/f2fs/f2fs.h > >> @@ -178,7 +178,6 @@ enum { > >> > >> #define MAX_DISCARD_BLOCKS(sbi) BLKS_PER_SEC(sbi) > >> #define DEF_MAX_DISCARD_REQUEST 8 /* issue 8 discards per round */ > >> -#define DEF_MAX_DISCARD_LEN 512 /* Max. 2MB per discard */ > >> #define DEF_MIN_DISCARD_ISSUE_TIME 50 /* 50 ms, if exists */ > >> #define DEF_MID_DISCARD_ISSUE_TIME 500 /* 500 ms, if device busy */ > >> #define DEF_MAX_DISCARD_ISSUE_TIME 60000 /* 60 s, if no candidates */ > >> @@ -701,22 +700,22 @@ static inline void set_extent_info(struct extent_info *ei, unsigned int fofs, > >> } > >> > >> static inline bool __is_discard_mergeable(struct discard_info *back, > >> - struct discard_info *front) > >> + struct discard_info *front, unsigned int max_len) > >> { > >> return (back->lstart + back->len == front->lstart) && > >> - (back->len + front->len < DEF_MAX_DISCARD_LEN); > >> + (back->len + front->len <= max_len); > >> } > >> > >> static inline bool __is_discard_back_mergeable(struct discard_info *cur, > >> - struct discard_info *back) > >> + struct discard_info *back, unsigned int max_len) > >> { > >> - return __is_discard_mergeable(back, cur); > >> + return __is_discard_mergeable(back, cur, max_len); > >> } > >> > >> static inline bool __is_discard_front_mergeable(struct discard_info *cur, > >> - struct discard_info *front) > >> + struct discard_info *front, unsigned int max_len) > >> { > >> - return __is_discard_mergeable(cur, front); > >> + return __is_discard_mergeable(cur, front, max_len); > >> } > >> > >> static inline bool __is_extent_mergeable(struct extent_info *back, > >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > >> index 4648561e2bfd..8e417a12684d 100644 > >> --- a/fs/f2fs/segment.c > >> +++ b/fs/f2fs/segment.c > >> @@ -1086,6 +1086,9 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> struct discard_cmd *dc; > >> struct discard_info di = {0}; > >> struct rb_node **insert_p = NULL, *insert_parent = NULL; > >> + struct request_queue *q = bdev_get_queue(bdev); > >> + unsigned int max_discard_blocks = > >> + SECTOR_TO_BLOCK(q->limits.max_discard_sectors); > >> block_t end = lstart + len; > >> > >> mutex_lock(&dcc->cmd_lock); > >> @@ -1129,7 +1132,8 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> > >> if (prev_dc && prev_dc->state == D_PREP && > >> prev_dc->bdev == bdev && > >> - __is_discard_back_mergeable(&di, &prev_dc->di)) { > >> + __is_discard_back_mergeable(&di, &prev_dc->di, > >> + max_discard_blocks)) { > >> prev_dc->di.len += di.len; > >> dcc->undiscard_blks += di.len; > >> __relocate_discard_cmd(dcc, prev_dc); > >> @@ -1140,7 +1144,8 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> > >> if (next_dc && next_dc->state == D_PREP && > >> next_dc->bdev == bdev && > >> - __is_discard_front_mergeable(&di, &next_dc->di)) { > >> + __is_discard_front_mergeable(&di, &next_dc->di, > >> + max_discard_blocks)) { > >> next_dc->di.lstart = di.lstart; > >> next_dc->di.len += di.len; > >> next_dc->di.start = di.start; > >> @@ -1170,7 +1175,11 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> static int __queue_discard_cmd(struct f2fs_sb_info *sbi, > >> struct block_device *bdev, block_t blkstart, block_t blklen) > >> { > >> + struct request_queue *q = bdev_get_queue(bdev); > >> + unsigned int max_discard_blocks = > >> + SECTOR_TO_BLOCK(q->limits.max_discard_sectors); > >> block_t lblkstart = blkstart; > >> + block_t total_len = blklen; > >> > >> trace_f2fs_queue_discard(bdev, blkstart, blklen); > >> > >> @@ -1179,7 +1188,17 @@ static int __queue_discard_cmd(struct f2fs_sb_info *sbi, > >> > >> blkstart -= FDEV(devi).start_blk; > >> } > >> - __update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen); > >> + > >> + while (total_len) { > >> + if (blklen > max_discard_blocks) > >> + blklen = max_discard_blocks; > >> + __update_discard_tree_range(sbi, bdev, lblkstart, > >> + blkstart, blklen); > >> + lblkstart += blklen; > >> + blkstart += blklen; > >> + total_len -= blklen; > >> + blklen = total_len; > >> + } > >> return 0; > >> } > >> > >> -- > >> 2.16.2.17.g38e79b1fd From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: Re: [PATCH] f2fs: split discard command in prior to block layer Date: Fri, 6 Jul 2018 18:08:34 -0700 Message-ID: <20180707010834.GA3767@jaegeuk-macbookpro.roam.corp.google.com> References: <20180704153746.2510-1-chao@kernel.org> <20180706224533.GC77984@jaegeuk-macbookpro.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1fbbiN-0005zw-8o for linux-f2fs-devel@lists.sourceforge.net; Sat, 07 Jul 2018 01:08:43 +0000 Received: from mail.kernel.org ([198.145.29.99]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) id 1fbbiL-00246w-9d for linux-f2fs-devel@lists.sourceforge.net; Sat, 07 Jul 2018 01:08:43 +0000 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net On 07/07, Chao Yu wrote: > Hi Jaegeuk, > > On 2018/7/7 6:45, Jaegeuk Kim wrote: > > On 07/04, Chao Yu wrote: > >> From: Chao Yu > >> > >> Some devices has small max_{hw,}discard_sectors, so that in > >> __blkdev_issue_discard(), one big size discard bio can be split > >> into multiple small size discard bios, result in heavy load in IO > >> scheduler and device, which can hang other sync IO for long time. > >> > >> Now, f2fs is trying to control discard commands more elaboratively, > >> in order to make less conflict in between discard IO and user IO > >> to enhance application's performance, so in this patch, we will > >> split discard bio in f2fs in prior to in block layer to reduce > >> issuing multiple discard bios in a short time. > > > > Hi Chao, > > > > In terms of # of candidates, can we control this when actually issuing > > the discard commands? > > IIUC, you mean once we pick one discard entry in rbtree, if > max_{hw,}discard_sectors is smaller than size of this discard, then we can split > it into smaller ones by discard_sectors, and just issue one or partials of them? Yes, sort of. > > Thanks, > > > > > Thanks, > > > >> > >> Signed-off-by: Chao Yu > >> --- > >> fs/f2fs/f2fs.h | 13 ++++++------- > >> fs/f2fs/segment.c | 25 ++++++++++++++++++++++--- > >> 2 files changed, 28 insertions(+), 10 deletions(-) > >> > >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > >> index a9da5a089cb4..a09d2b2d9520 100644 > >> --- a/fs/f2fs/f2fs.h > >> +++ b/fs/f2fs/f2fs.h > >> @@ -178,7 +178,6 @@ enum { > >> > >> #define MAX_DISCARD_BLOCKS(sbi) BLKS_PER_SEC(sbi) > >> #define DEF_MAX_DISCARD_REQUEST 8 /* issue 8 discards per round */ > >> -#define DEF_MAX_DISCARD_LEN 512 /* Max. 2MB per discard */ > >> #define DEF_MIN_DISCARD_ISSUE_TIME 50 /* 50 ms, if exists */ > >> #define DEF_MID_DISCARD_ISSUE_TIME 500 /* 500 ms, if device busy */ > >> #define DEF_MAX_DISCARD_ISSUE_TIME 60000 /* 60 s, if no candidates */ > >> @@ -701,22 +700,22 @@ static inline void set_extent_info(struct extent_info *ei, unsigned int fofs, > >> } > >> > >> static inline bool __is_discard_mergeable(struct discard_info *back, > >> - struct discard_info *front) > >> + struct discard_info *front, unsigned int max_len) > >> { > >> return (back->lstart + back->len == front->lstart) && > >> - (back->len + front->len < DEF_MAX_DISCARD_LEN); > >> + (back->len + front->len <= max_len); > >> } > >> > >> static inline bool __is_discard_back_mergeable(struct discard_info *cur, > >> - struct discard_info *back) > >> + struct discard_info *back, unsigned int max_len) > >> { > >> - return __is_discard_mergeable(back, cur); > >> + return __is_discard_mergeable(back, cur, max_len); > >> } > >> > >> static inline bool __is_discard_front_mergeable(struct discard_info *cur, > >> - struct discard_info *front) > >> + struct discard_info *front, unsigned int max_len) > >> { > >> - return __is_discard_mergeable(cur, front); > >> + return __is_discard_mergeable(cur, front, max_len); > >> } > >> > >> static inline bool __is_extent_mergeable(struct extent_info *back, > >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > >> index 4648561e2bfd..8e417a12684d 100644 > >> --- a/fs/f2fs/segment.c > >> +++ b/fs/f2fs/segment.c > >> @@ -1086,6 +1086,9 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> struct discard_cmd *dc; > >> struct discard_info di = {0}; > >> struct rb_node **insert_p = NULL, *insert_parent = NULL; > >> + struct request_queue *q = bdev_get_queue(bdev); > >> + unsigned int max_discard_blocks = > >> + SECTOR_TO_BLOCK(q->limits.max_discard_sectors); > >> block_t end = lstart + len; > >> > >> mutex_lock(&dcc->cmd_lock); > >> @@ -1129,7 +1132,8 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> > >> if (prev_dc && prev_dc->state == D_PREP && > >> prev_dc->bdev == bdev && > >> - __is_discard_back_mergeable(&di, &prev_dc->di)) { > >> + __is_discard_back_mergeable(&di, &prev_dc->di, > >> + max_discard_blocks)) { > >> prev_dc->di.len += di.len; > >> dcc->undiscard_blks += di.len; > >> __relocate_discard_cmd(dcc, prev_dc); > >> @@ -1140,7 +1144,8 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> > >> if (next_dc && next_dc->state == D_PREP && > >> next_dc->bdev == bdev && > >> - __is_discard_front_mergeable(&di, &next_dc->di)) { > >> + __is_discard_front_mergeable(&di, &next_dc->di, > >> + max_discard_blocks)) { > >> next_dc->di.lstart = di.lstart; > >> next_dc->di.len += di.len; > >> next_dc->di.start = di.start; > >> @@ -1170,7 +1175,11 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, > >> static int __queue_discard_cmd(struct f2fs_sb_info *sbi, > >> struct block_device *bdev, block_t blkstart, block_t blklen) > >> { > >> + struct request_queue *q = bdev_get_queue(bdev); > >> + unsigned int max_discard_blocks = > >> + SECTOR_TO_BLOCK(q->limits.max_discard_sectors); > >> block_t lblkstart = blkstart; > >> + block_t total_len = blklen; > >> > >> trace_f2fs_queue_discard(bdev, blkstart, blklen); > >> > >> @@ -1179,7 +1188,17 @@ static int __queue_discard_cmd(struct f2fs_sb_info *sbi, > >> > >> blkstart -= FDEV(devi).start_blk; > >> } > >> - __update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen); > >> + > >> + while (total_len) { > >> + if (blklen > max_discard_blocks) > >> + blklen = max_discard_blocks; > >> + __update_discard_tree_range(sbi, bdev, lblkstart, > >> + blkstart, blklen); > >> + lblkstart += blklen; > >> + blkstart += blklen; > >> + total_len -= blklen; > >> + blklen = total_len; > >> + } > >> return 0; > >> } > >> > >> -- > >> 2.16.2.17.g38e79b1fd ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot