From 65299a3b788bd274bed92f9fa3232082c9f3ea70 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 23 Aug 2011 14:50:29 +0200 Subject: [PATCH] block: separate priority boosting from REQ_META Add a new REQ_PRIO to let requests preempt others in the cfq I/O schedule, and lave REQ_META purely for marking requests as metadata in blktrace. All existing callers of REQ_META except for XFS are updated to also set REQ_PRIO for now. Signed-off-by: Christoph Hellwig Reviewed-by: Namhyung Kim Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 20 ++++++++++---------- drivers/mmc/card/block.c | 3 +++ fs/ext3/inode.c | 4 ++-- fs/ext3/namei.c | 3 ++- fs/ext4/inode.c | 4 ++-- fs/ext4/namei.c | 3 ++- fs/gfs2/log.c | 4 ++-- fs/gfs2/meta_io.c | 6 +++--- fs/gfs2/ops_fstype.c | 2 +- fs/gfs2/quota.c | 2 +- include/linux/blk_types.h | 6 ++++-- 11 files changed, 32 insertions(+), 25 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index a33bd4377c61..16ace89613bc 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -130,8 +130,8 @@ struct cfq_queue { unsigned long slice_end; long slice_resid; - /* pending metadata requests */ - int meta_pending; + /* pending priority requests */ + int prio_pending; /* number of requests that are on the dispatch list or inside driver */ int dispatched; @@ -684,8 +684,8 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, if (rq_is_sync(rq1) != rq_is_sync(rq2)) return rq_is_sync(rq1) ? rq1 : rq2; - if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_META) - return rq1->cmd_flags & REQ_META ? rq1 : rq2; + if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO) + return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2; s1 = blk_rq_pos(rq1); s2 = blk_rq_pos(rq2); @@ -1612,9 +1612,9 @@ static void cfq_remove_request(struct request *rq) cfqq->cfqd->rq_queued--; cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(rq), rq_is_sync(rq)); - if (rq->cmd_flags & REQ_META) { - WARN_ON(!cfqq->meta_pending); - cfqq->meta_pending--; + if (rq->cmd_flags & REQ_PRIO) { + WARN_ON(!cfqq->prio_pending); + cfqq->prio_pending--; } } @@ -3372,7 +3372,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, * So both queues are sync. Let the new request get disk time if * it's a metadata request and the current queue is doing regular IO. */ - if ((rq->cmd_flags & REQ_META) && !cfqq->meta_pending) + if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending) return true; /* @@ -3439,8 +3439,8 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, struct cfq_io_context *cic = RQ_CIC(rq); cfqd->rq_queued++; - if (rq->cmd_flags & REQ_META) - cfqq->meta_pending++; + if (rq->cmd_flags & REQ_PRIO) + cfqq->prio_pending++; cfq_update_io_thinktime(cfqd, cfqq, cic); cfq_update_io_seektime(cfqd, cfqq, rq); diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 1ff5486213fb..4c1a648d00fc 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -926,6 +926,9 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq, /* * Reliable writes are used to implement Forced Unit Access and * REQ_META accesses, and are supported only on MMCs. + * + * XXX: this really needs a good explanation of why REQ_META + * is treated special. */ bool do_rel_wr = ((req->cmd_flags & REQ_FUA) || (req->cmd_flags & REQ_META)) && diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index bba7b96e0d9b..12661e1deedd 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -1134,7 +1134,7 @@ struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode, return bh; if (buffer_uptodate(bh)) return bh; - ll_rw_block(READ | REQ_META, 1, &bh); + ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh); wait_on_buffer(bh); if (buffer_uptodate(bh)) return bh; @@ -2807,7 +2807,7 @@ make_io: trace_ext3_load_inode(inode); get_bh(bh); bh->b_end_io = end_buffer_read_sync; - submit_bh(READ | REQ_META, bh); + submit_bh(READ | REQ_META | REQ_PRIO, bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) { ext3_error(inode->i_sb, "ext3_get_inode_loc", diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c index c7d4032aa82a..0629e09f6511 100644 --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -922,7 +922,8 @@ restart: bh = ext3_getblk(NULL, dir, b++, 0, &err); bh_use[ra_max] = bh; if (bh) - ll_rw_block(READ | REQ_META, 1, &bh); + ll_rw_block(READ | REQ_META | REQ_PRIO, + 1, &bh); } } if ((bh = bh_use[ra_ptr++]) == NULL) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 1dfa18feeb3e..c7cbb3d85d9e 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -650,7 +650,7 @@ struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, return bh; if (buffer_uptodate(bh)) return bh; - ll_rw_block(READ | REQ_META, 1, &bh); + ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh); wait_on_buffer(bh); if (buffer_uptodate(bh)) return bh; @@ -3301,7 +3301,7 @@ make_io: trace_ext4_load_inode(inode); get_bh(bh); bh->b_end_io = end_buffer_read_sync; - submit_bh(READ | REQ_META, bh); + submit_bh(READ | REQ_META | REQ_PRIO, bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) { EXT4_ERROR_INODE_BLOCK(inode, block, diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index d36315ae629e..1c924faeb6c8 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -922,7 +922,8 @@ restart: bh = ext4_getblk(NULL, dir, b++, 0, &err); bh_use[ra_max] = bh; if (bh) - ll_rw_block(READ | REQ_META, 1, &bh); + ll_rw_block(READ | REQ_META | REQ_PRIO, + 1, &bh); } } if ((bh = bh_use[ra_ptr++]) == NULL) diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 85c62923ee29..598646434362 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -624,9 +624,9 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull) bh->b_end_io = end_buffer_write_sync; get_bh(bh); if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) - submit_bh(WRITE_SYNC | REQ_META, bh); + submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh); else - submit_bh(WRITE_FLUSH_FUA | REQ_META, bh); + submit_bh(WRITE_FLUSH_FUA | REQ_META | REQ_PRIO, bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c index 747238cd9f96..be29858900f6 100644 --- a/fs/gfs2/meta_io.c +++ b/fs/gfs2/meta_io.c @@ -37,7 +37,7 @@ static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wb { struct buffer_head *bh, *head; int nr_underway = 0; - int write_op = REQ_META | + int write_op = REQ_META | REQ_PRIO | (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); BUG_ON(!PageLocked(page)); @@ -225,7 +225,7 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, } bh->b_end_io = end_buffer_read_sync; get_bh(bh); - submit_bh(READ_SYNC | REQ_META, bh); + submit_bh(READ_SYNC | REQ_META | REQ_PRIO, bh); if (!(flags & DIO_WAIT)) return 0; @@ -435,7 +435,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen) if (buffer_uptodate(first_bh)) goto out; if (!buffer_locked(first_bh)) - ll_rw_block(READ_SYNC | REQ_META, 1, &first_bh); + ll_rw_block(READ_SYNC | REQ_META | REQ_PRIO, 1, &first_bh); dblock++; extlen--; diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index 3bc073a4cf82..079587e53849 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -224,7 +224,7 @@ static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent) bio->bi_end_io = end_bio_io_page; bio->bi_private = page; - submit_bio(READ_SYNC | REQ_META, bio); + submit_bio(READ_SYNC | REQ_META | REQ_PRIO, bio); wait_on_page_locked(page); bio_put(bio); if (!PageUptodate(page)) { diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c index 053434049dbb..0e8bb13381e4 100644 --- a/fs/gfs2/quota.c +++ b/fs/gfs2/quota.c @@ -709,7 +709,7 @@ get_a_page: set_buffer_uptodate(bh); if (!buffer_uptodate(bh)) { - ll_rw_block(READ | REQ_META, 1, &bh); + ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) goto unlock_out; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 32f0076e844b..71fc53bb8f1c 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -124,6 +124,7 @@ enum rq_flag_bits { __REQ_SYNC, /* request is sync (sync write or read) */ __REQ_META, /* metadata io request */ + __REQ_PRIO, /* boost priority in cfq */ __REQ_DISCARD, /* request to discard sectors */ __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ @@ -161,14 +162,15 @@ enum rq_flag_bits { #define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER) #define REQ_SYNC (1 << __REQ_SYNC) #define REQ_META (1 << __REQ_META) +#define REQ_PRIO (1 << __REQ_PRIO) #define REQ_DISCARD (1 << __REQ_DISCARD) #define REQ_NOIDLE (1 << __REQ_NOIDLE) #define REQ_FAILFAST_MASK \ (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) #define REQ_COMMON_MASK \ - (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_DISCARD | \ - REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE) + (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \ + REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE) #define REQ_CLONE_MASK REQ_COMMON_MASK #define REQ_RAHEAD (1 << __REQ_RAHEAD) -- 2.30.2