From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 8 Mar 2017 13:43:11 -0800 From: Jaegeuk Kim To: Christoph Hellwig 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: <20170308214311.GD5483@jaegeuk.local> References: <20170308023333.15034-1-jaegeuk@kernel.org> <20170308150311.GA17999@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170308150311.GA17999@infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: On 03/08, Christoph Hellwig wrote: > 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? No, the patch just changes bio_alloc timings, but the stall happens when doing submit_bio. Thanks, > > > > > 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---