From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([65.50.211.133]:47853 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750822AbdCHP3y (ORCPT ); Wed, 8 Mar 2017 10:29:54 -0500 Date: Wed, 8 Mar 2017 07:03:11 -0800 From: Christoph Hellwig To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-block@vger.kernel.org Subject: Re: [PATCH] f2fs: allocate a bio for discarding when actually issuing it Message-ID: <20170308150311.GA17999@infradead.org> References: <20170308023333.15034-1-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170308023333.15034-1-jaegeuk@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Mar 07, 2017 at 06:33:33PM -0800, Jaegeuk Kim wrote: > Let's allocate a bio when issuing discard commands later. Does this solve the issue with your queue stalls? > > Signed-off-by: Jaegeuk Kim > --- > fs/f2fs/f2fs.h | 4 +- > fs/f2fs/segment.c | 113 ++++++++++++++++++++++++++++-------------------------- > 2 files changed, 62 insertions(+), 55 deletions(-) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index a58c2e43bd2a..870bb4d9bc65 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -197,10 +197,12 @@ enum { > struct discard_cmd { > struct list_head list; /* command list */ > struct completion wait; /* compleation */ > + struct block_device *bdev; /* bdev */ > block_t lstart; /* logical start address */ > + block_t start; /* actual start address in dev */ > block_t len; /* length */ > - struct bio *bio; /* bio */ > int state; /* state */ > + int error; /* bio error */ > }; > > struct discard_cmd_control { > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 50c65cc4645a..d8f9e6c895cd 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -636,7 +636,8 @@ static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno) > } > > static void __add_discard_cmd(struct f2fs_sb_info *sbi, > - struct bio *bio, block_t lstart, block_t len) > + struct block_device *bdev, block_t lstart, > + block_t start, block_t len) > { > struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info; > struct list_head *cmd_list = &(dcc->discard_cmd_list); > @@ -644,9 +645,9 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi, > > dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS); > INIT_LIST_HEAD(&dc->list); > - dc->bio = bio; > - bio->bi_private = dc; > + dc->bdev = bdev; > dc->lstart = lstart; > + dc->start = start; > dc->len = len; > dc->state = D_PREP; > init_completion(&dc->wait); > @@ -658,22 +659,66 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi, > > static void __remove_discard_cmd(struct f2fs_sb_info *sbi, struct discard_cmd *dc) > { > - int err = dc->bio->bi_error; > - > if (dc->state == D_DONE) > atomic_dec(&(SM_I(sbi)->dcc_info->submit_discard)); > > - if (err == -EOPNOTSUPP) > - err = 0; > + if (dc->error == -EOPNOTSUPP) > + dc->error = 0; > > - if (err) > + if (dc->error) > f2fs_msg(sbi->sb, KERN_INFO, > - "Issue discard failed, ret: %d", err); > - bio_put(dc->bio); > + "Issue discard failed, ret: %d", dc->error); > list_del(&dc->list); > kmem_cache_free(discard_cmd_slab, dc); > } > > +static void f2fs_submit_discard_endio(struct bio *bio) > +{ > + struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private; > + > + complete(&dc->wait); > + dc->error = bio->bi_error; > + dc->state = D_DONE; > + bio_put(bio); > +} > + > +/* this function is copied from blkdev_issue_discard from block/blk-lib.c */ > +static int __submit_discard_cmd(struct discard_cmd *dc) > +{ > + struct bio *bio = NULL; > + int err; > + > + err = __blkdev_issue_discard(dc->bdev, > + SECTOR_FROM_BLOCK(dc->start), > + SECTOR_FROM_BLOCK(dc->len), > + GFP_NOFS, 0, &bio); > + if (!err && bio) { > + bio->bi_private = dc; > + bio->bi_end_io = f2fs_submit_discard_endio; > + bio->bi_opf |= REQ_SYNC; > + submit_bio(bio); > + } > + dc->state = D_SUBMIT; > + return err; > +} > + > +static int __queue_discard_cmd(struct f2fs_sb_info *sbi, > + struct block_device *bdev, block_t blkstart, block_t blklen) > +{ > + block_t lblkstart = blkstart; > + > + trace_f2fs_issue_discard(bdev, blkstart, blklen); > + > + if (sbi->s_ndevs) { > + int devi = f2fs_target_device_index(sbi, blkstart); > + > + blkstart -= FDEV(devi).start_blk; > + } > + __add_discard_cmd(sbi, bdev, lblkstart, blkstart, blklen); > + wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue); > + return 0; > +} > + > /* This should be covered by global mutex, &sit_i->sentry_lock */ > void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr) > { > @@ -690,8 +735,7 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr) > > if (blkaddr == NULL_ADDR) { > if (dc->state == D_PREP) { > - dc->state = D_SUBMIT; > - submit_bio(dc->bio); > + __submit_discard_cmd(dc); > atomic_inc(&dcc->submit_discard); > } > continue; > @@ -716,14 +760,6 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr) > mutex_unlock(&dcc->cmd_lock); > } > > -static void f2fs_submit_discard_endio(struct bio *bio) > -{ > - struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private; > - > - complete(&dc->wait); > - dc->state = D_DONE; > -} > - > static int issue_discard_thread(void *data) > { > struct f2fs_sb_info *sbi = data; > @@ -742,8 +778,7 @@ static int issue_discard_thread(void *data) > mutex_lock(&dcc->cmd_lock); > list_for_each_entry_safe(dc, tmp, cmd_list, list) { > if (dc->state == D_PREP) { > - dc->state = D_SUBMIT; > - submit_bio(dc->bio); > + __submit_discard_cmd(dc); > atomic_inc(&dcc->submit_discard); > if (iter++ > DISCARD_ISSUE_RATE) > break; > @@ -763,36 +798,6 @@ static int issue_discard_thread(void *data) > goto repeat; > } > > - > -/* this function is copied from blkdev_issue_discard from block/blk-lib.c */ > -static int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi, > - struct block_device *bdev, block_t blkstart, block_t blklen) > -{ > - struct bio *bio = NULL; > - block_t lblkstart = blkstart; > - int err; > - > - trace_f2fs_issue_discard(bdev, blkstart, blklen); > - > - if (sbi->s_ndevs) { > - int devi = f2fs_target_device_index(sbi, blkstart); > - > - blkstart -= FDEV(devi).start_blk; > - } > - err = __blkdev_issue_discard(bdev, > - SECTOR_FROM_BLOCK(blkstart), > - SECTOR_FROM_BLOCK(blklen), > - GFP_NOFS, 0, &bio); > - if (!err && bio) { > - bio->bi_end_io = f2fs_submit_discard_endio; > - bio->bi_opf |= REQ_SYNC; > - > - __add_discard_cmd(sbi, bio, lblkstart, blklen); > - wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue); > - } > - return err; > -} > - > #ifdef CONFIG_BLK_DEV_ZONED > static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi, > struct block_device *bdev, block_t blkstart, block_t blklen) > @@ -816,7 +821,7 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi, > case BLK_ZONE_TYPE_CONVENTIONAL: > if (!blk_queue_discard(bdev_get_queue(bdev))) > return 0; > - return __f2fs_issue_discard_async(sbi, bdev, lblkstart, blklen); > + return __queue_discard_cmd(sbi, bdev, lblkstart, blklen); > case BLK_ZONE_TYPE_SEQWRITE_REQ: > case BLK_ZONE_TYPE_SEQWRITE_PREF: > sector = SECTOR_FROM_BLOCK(blkstart); > @@ -848,7 +853,7 @@ static int __issue_discard_async(struct f2fs_sb_info *sbi, > bdev_zoned_model(bdev) != BLK_ZONED_NONE) > return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen); > #endif > - return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen); > + return __queue_discard_cmd(sbi, bdev, blkstart, blklen); > } > > static int f2fs_issue_discard(struct f2fs_sb_info *sbi, > -- > 2.11.0 > ---end quoted text---