From c8a446ad695ada43a885ec12b38411dbd190a11b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 13 Sep 2014 16:40:10 -0700 Subject: blk-mq: rename blk_mq_end_io to blk_mq_end_request Now that we've changed the driver API on the submission side use the opportunity to fix up the name on the completion side to fit into the general scheme. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-flush.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index 3cb5e9e..698e692 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -202,7 +202,7 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, list_del_init(&rq->flush.list); blk_flush_restore_request(rq); if (q->mq_ops) - blk_mq_end_io(rq, error); + blk_mq_end_request(rq, error); else __blk_end_request_all(rq, error); break; @@ -378,7 +378,7 @@ void blk_insert_flush(struct request *rq) */ if (!policy) { if (q->mq_ops) - blk_mq_end_io(rq, 0); + blk_mq_end_request(rq, 0); else __blk_end_bidi_request(rq, 0, 0, 0); return; -- cgit v1.1 From 2edd2c740b2918eb0a9a1fe1b69678b903769ec2 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 17 Sep 2014 17:47:58 +0800 Subject: blk-mq: remove unnecessary blk_clear_rq_complete() This patch removes two unnecessary blk_clear_rq_complete(), the REQ_ATOM_COMPLETE flag is cleared inside blk_mq_start_request(), so: - The blk_clear_rq_complete() in blk_flush_restore_request() needn't because the request will be freed later, and clearing it here may open a small race window with timeout. - The blk_clear_rq_complete() in blk_mq_requeue_request() isn't necessary too, even though REQ_ATOM_STARTED is cleared in __blk_mq_requeue_request(), in theory it still may cause a small race window with timeout since the two clear_bit() may be reordered. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index 698e692..c8e2576 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -126,8 +126,6 @@ static void blk_flush_restore_request(struct request *rq) /* make @rq a normal request */ rq->cmd_flags &= ~REQ_FLUSH_SEQ; rq->end_io = rq->flush.saved_end_io; - - blk_clear_rq_complete(rq); } static bool blk_flush_queue_rq(struct request *rq, bool add_front) -- cgit v1.1 From 1bcb1eada4f11a713cbe586d1b5a5d93a48277cb Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:39 +0800 Subject: blk-mq: allocate flush_rq in blk_mq_init_flush() It is reasonable to allocate flush req in blk_mq_init_flush(). Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index c8e2576..55028a7 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -472,7 +472,16 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, } EXPORT_SYMBOL(blkdev_issue_flush); -void blk_mq_init_flush(struct request_queue *q) +int blk_mq_init_flush(struct request_queue *q) { + struct blk_mq_tag_set *set = q->tag_set; + spin_lock_init(&q->mq_flush_lock); + + q->flush_rq = kzalloc(round_up(sizeof(struct request) + + set->cmd_size, cache_line_size()), + GFP_KERNEL); + if (!q->flush_rq) + return -ENOMEM; + return 0; } -- cgit v1.1 From f355265571440a7db16e784b6edf4e7d26971a03 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:40 +0800 Subject: block: introduce blk_init_flush and its pair These two temporary functions are introduced for holding flush initialization and de-initialization, so that we can introduce 'flush queue' easier in the following patch. And once 'flush queue' and its allocation/free functions are ready, they will be removed for sake of code readability. Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index 55028a7..c72ab32 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -472,7 +472,7 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, } EXPORT_SYMBOL(blkdev_issue_flush); -int blk_mq_init_flush(struct request_queue *q) +static int blk_mq_init_flush(struct request_queue *q) { struct blk_mq_tag_set *set = q->tag_set; @@ -485,3 +485,20 @@ int blk_mq_init_flush(struct request_queue *q) return -ENOMEM; return 0; } + +int blk_init_flush(struct request_queue *q) +{ + if (q->mq_ops) + return blk_mq_init_flush(q); + + q->flush_rq = kzalloc(sizeof(struct request), GFP_KERNEL); + if (!q->flush_rq) + return -ENOMEM; + + return 0; +} + +void blk_exit_flush(struct request_queue *q) +{ + kfree(q->flush_rq); +} -- cgit v1.1 From 3c09676c12b1dabf84acbb5849bfc54acadaf092 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:41 +0800 Subject: block: move flush initialization to blk_flush_init These fields are always used with the flush request, so initialize them together. Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index c72ab32..a49ffbd 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -488,6 +488,10 @@ static int blk_mq_init_flush(struct request_queue *q) int blk_init_flush(struct request_queue *q) { + INIT_LIST_HEAD(&q->flush_queue[0]); + INIT_LIST_HEAD(&q->flush_queue[1]); + INIT_LIST_HEAD(&q->flush_data_in_flight); + if (q->mq_ops) return blk_mq_init_flush(q); -- cgit v1.1 From 7ddab5de5b80d3111f9e6765714e728b2c4f1c07 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:42 +0800 Subject: block: avoid to use q->flush_rq directly This patch trys to use local variable to access flush request, so that we can convert to per-queue flush machinery a bit easier. Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index a49ffbd..caf44756 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -223,7 +223,7 @@ static void flush_end_io(struct request *flush_rq, int error) if (q->mq_ops) { spin_lock_irqsave(&q->mq_flush_lock, flags); - q->flush_rq->tag = -1; + flush_rq->tag = -1; } running = &q->flush_queue[q->flush_running_idx]; @@ -281,6 +281,7 @@ static bool blk_kick_flush(struct request_queue *q) struct list_head *pending = &q->flush_queue[q->flush_pending_idx]; struct request *first_rq = list_first_entry(pending, struct request, flush.list); + struct request *flush_rq = q->flush_rq; /* C1 described at the top of this file */ if (q->flush_pending_idx != q->flush_running_idx || list_empty(pending)) @@ -298,16 +299,16 @@ static bool blk_kick_flush(struct request_queue *q) */ q->flush_pending_idx ^= 1; - blk_rq_init(q, q->flush_rq); + blk_rq_init(q, flush_rq); if (q->mq_ops) - blk_mq_clone_flush_request(q->flush_rq, first_rq); + blk_mq_clone_flush_request(flush_rq, first_rq); - q->flush_rq->cmd_type = REQ_TYPE_FS; - q->flush_rq->cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ; - q->flush_rq->rq_disk = first_rq->rq_disk; - q->flush_rq->end_io = flush_end_io; + flush_rq->cmd_type = REQ_TYPE_FS; + flush_rq->cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ; + flush_rq->rq_disk = first_rq->rq_disk; + flush_rq->end_io = flush_end_io; - return blk_flush_queue_rq(q->flush_rq, false); + return blk_flush_queue_rq(flush_rq, false); } static void flush_data_end_io(struct request *rq, int error) -- cgit v1.1 From 7c94e1c157a227837b04f02f5edeff8301410ba2 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:43 +0800 Subject: block: introduce blk_flush_queue to drive flush machinery This patch introduces 'struct blk_flush_queue' and puts all flush machinery related fields into this structure, so that - flush implementation details aren't exposed to driver - it is easy to convert to per dispatch-queue flush machinery This patch is basically a mechanical replacement. Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 109 ++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 68 insertions(+), 41 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index caf44756..b01a86d 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -28,7 +28,7 @@ * * The actual execution of flush is double buffered. Whenever a request * needs to execute PRE or POSTFLUSH, it queues at - * q->flush_queue[q->flush_pending_idx]. Once certain criteria are met, a + * fq->flush_queue[fq->flush_pending_idx]. Once certain criteria are met, a * flush is issued and the pending_idx is toggled. When the flush * completes, all the requests which were pending are proceeded to the next * step. This allows arbitrary merging of different types of FLUSH/FUA @@ -155,7 +155,7 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front) * completion and trigger the next step. * * CONTEXT: - * spin_lock_irq(q->queue_lock or q->mq_flush_lock) + * spin_lock_irq(q->queue_lock or fq->mq_flush_lock) * * RETURNS: * %true if requests were added to the dispatch queue, %false otherwise. @@ -164,7 +164,8 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, int error) { struct request_queue *q = rq->q; - struct list_head *pending = &q->flush_queue[q->flush_pending_idx]; + struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; bool queued = false, kicked; BUG_ON(rq->flush.seq & seq); @@ -180,12 +181,12 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, case REQ_FSEQ_POSTFLUSH: /* queue for flush */ if (list_empty(pending)) - q->flush_pending_since = jiffies; + fq->flush_pending_since = jiffies; list_move_tail(&rq->flush.list, pending); break; case REQ_FSEQ_DATA: - list_move_tail(&rq->flush.list, &q->flush_data_in_flight); + list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); queued = blk_flush_queue_rq(rq, true); break; @@ -220,17 +221,18 @@ static void flush_end_io(struct request *flush_rq, int error) bool queued = false; struct request *rq, *n; unsigned long flags = 0; + struct blk_flush_queue *fq = blk_get_flush_queue(q); if (q->mq_ops) { - spin_lock_irqsave(&q->mq_flush_lock, flags); + spin_lock_irqsave(&fq->mq_flush_lock, flags); flush_rq->tag = -1; } - running = &q->flush_queue[q->flush_running_idx]; - BUG_ON(q->flush_pending_idx == q->flush_running_idx); + running = &fq->flush_queue[fq->flush_running_idx]; + BUG_ON(fq->flush_pending_idx == fq->flush_running_idx); /* account completion of the flush request */ - q->flush_running_idx ^= 1; + fq->flush_running_idx ^= 1; if (!q->mq_ops) elv_completed_request(q, flush_rq); @@ -254,13 +256,13 @@ static void flush_end_io(struct request *flush_rq, int error) * directly into request_fn may confuse the driver. Always use * kblockd. */ - if (queued || q->flush_queue_delayed) { + if (queued || fq->flush_queue_delayed) { WARN_ON(q->mq_ops); blk_run_queue_async(q); } - q->flush_queue_delayed = 0; + fq->flush_queue_delayed = 0; if (q->mq_ops) - spin_unlock_irqrestore(&q->mq_flush_lock, flags); + spin_unlock_irqrestore(&fq->mq_flush_lock, flags); } /** @@ -271,33 +273,34 @@ static void flush_end_io(struct request *flush_rq, int error) * Please read the comment at the top of this file for more info. * * CONTEXT: - * spin_lock_irq(q->queue_lock or q->mq_flush_lock) + * spin_lock_irq(q->queue_lock or fq->mq_flush_lock) * * RETURNS: * %true if flush was issued, %false otherwise. */ static bool blk_kick_flush(struct request_queue *q) { - struct list_head *pending = &q->flush_queue[q->flush_pending_idx]; + struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; struct request *first_rq = list_first_entry(pending, struct request, flush.list); - struct request *flush_rq = q->flush_rq; + struct request *flush_rq = fq->flush_rq; /* C1 described at the top of this file */ - if (q->flush_pending_idx != q->flush_running_idx || list_empty(pending)) + if (fq->flush_pending_idx != fq->flush_running_idx || list_empty(pending)) return false; /* C2 and C3 */ - if (!list_empty(&q->flush_data_in_flight) && + if (!list_empty(&fq->flush_data_in_flight) && time_before(jiffies, - q->flush_pending_since + FLUSH_PENDING_TIMEOUT)) + fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) return false; /* * Issue flush and toggle pending_idx. This makes pending_idx * different from running_idx, which means flush is in flight. */ - q->flush_pending_idx ^= 1; + fq->flush_pending_idx ^= 1; blk_rq_init(q, flush_rq); if (q->mq_ops) @@ -329,6 +332,7 @@ static void mq_flush_data_end_io(struct request *rq, int error) struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; unsigned long flags; + struct blk_flush_queue *fq = blk_get_flush_queue(q); ctx = rq->mq_ctx; hctx = q->mq_ops->map_queue(q, ctx->cpu); @@ -337,10 +341,10 @@ static void mq_flush_data_end_io(struct request *rq, int error) * After populating an empty queue, kick it to avoid stall. Read * the comment in flush_end_io(). */ - spin_lock_irqsave(&q->mq_flush_lock, flags); + spin_lock_irqsave(&fq->mq_flush_lock, flags); if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error)) blk_mq_run_hw_queue(hctx, true); - spin_unlock_irqrestore(&q->mq_flush_lock, flags); + spin_unlock_irqrestore(&fq->mq_flush_lock, flags); } /** @@ -408,11 +412,13 @@ void blk_insert_flush(struct request *rq) rq->cmd_flags |= REQ_FLUSH_SEQ; rq->flush.saved_end_io = rq->end_io; /* Usually NULL */ if (q->mq_ops) { + struct blk_flush_queue *fq = blk_get_flush_queue(q); + rq->end_io = mq_flush_data_end_io; - spin_lock_irq(&q->mq_flush_lock); + spin_lock_irq(&fq->mq_flush_lock); blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0); - spin_unlock_irq(&q->mq_flush_lock); + spin_unlock_irq(&fq->mq_flush_lock); return; } rq->end_io = flush_data_end_io; @@ -473,31 +479,52 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, } EXPORT_SYMBOL(blkdev_issue_flush); -static int blk_mq_init_flush(struct request_queue *q) +static struct blk_flush_queue *blk_alloc_flush_queue( + struct request_queue *q) { - struct blk_mq_tag_set *set = q->tag_set; + struct blk_flush_queue *fq; + int rq_sz = sizeof(struct request); - spin_lock_init(&q->mq_flush_lock); + fq = kzalloc(sizeof(*fq), GFP_KERNEL); + if (!fq) + goto fail; - q->flush_rq = kzalloc(round_up(sizeof(struct request) + - set->cmd_size, cache_line_size()), - GFP_KERNEL); - if (!q->flush_rq) - return -ENOMEM; - return 0; + if (q->mq_ops) { + spin_lock_init(&fq->mq_flush_lock); + rq_sz = round_up(rq_sz + q->tag_set->cmd_size, + cache_line_size()); + } + + fq->flush_rq = kzalloc(rq_sz, GFP_KERNEL); + if (!fq->flush_rq) + goto fail_rq; + + INIT_LIST_HEAD(&fq->flush_queue[0]); + INIT_LIST_HEAD(&fq->flush_queue[1]); + INIT_LIST_HEAD(&fq->flush_data_in_flight); + + return fq; + + fail_rq: + kfree(fq); + fail: + return NULL; } -int blk_init_flush(struct request_queue *q) +static void blk_free_flush_queue(struct blk_flush_queue *fq) { - INIT_LIST_HEAD(&q->flush_queue[0]); - INIT_LIST_HEAD(&q->flush_queue[1]); - INIT_LIST_HEAD(&q->flush_data_in_flight); + /* bio based request queue hasn't flush queue */ + if (!fq) + return; - if (q->mq_ops) - return blk_mq_init_flush(q); + kfree(fq->flush_rq); + kfree(fq); +} - q->flush_rq = kzalloc(sizeof(struct request), GFP_KERNEL); - if (!q->flush_rq) +int blk_init_flush(struct request_queue *q) +{ + q->fq = blk_alloc_flush_queue(q); + if (!q->fq) return -ENOMEM; return 0; @@ -505,5 +532,5 @@ int blk_init_flush(struct request_queue *q) void blk_exit_flush(struct request_queue *q) { - kfree(q->flush_rq); + blk_free_flush_queue(q->fq); } -- cgit v1.1 From ba483388e3058b3e412632a84e6bf1f134beaf3d Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:44 +0800 Subject: block: remove blk_init_flush() and its pair Now mission of the two helpers is over, and just call blk_alloc_flush_queue() and blk_free_flush_queue() directly. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 19 ++----------------- 1 file changed, 2 insertions(+), 17 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index b01a86d..d66cbf2 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -479,8 +479,7 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, } EXPORT_SYMBOL(blkdev_issue_flush); -static struct blk_flush_queue *blk_alloc_flush_queue( - struct request_queue *q) +struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q) { struct blk_flush_queue *fq; int rq_sz = sizeof(struct request); @@ -511,7 +510,7 @@ static struct blk_flush_queue *blk_alloc_flush_queue( return NULL; } -static void blk_free_flush_queue(struct blk_flush_queue *fq) +void blk_free_flush_queue(struct blk_flush_queue *fq) { /* bio based request queue hasn't flush queue */ if (!fq) @@ -520,17 +519,3 @@ static void blk_free_flush_queue(struct blk_flush_queue *fq) kfree(fq->flush_rq); kfree(fq); } - -int blk_init_flush(struct request_queue *q) -{ - q->fq = blk_alloc_flush_queue(q); - if (!q->fq) - return -ENOMEM; - - return 0; -} - -void blk_exit_flush(struct request_queue *q) -{ - blk_free_flush_queue(q->fq); -} -- cgit v1.1 From 0bae352da54a95435f721705d3670a6eaefdcf87 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:45 +0800 Subject: block: flush: avoid to figure out flush queue unnecessarily Just figuring out flush queue at the entry of kicking off flush machinery and request's completion handler, then pass it through. Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index d66cbf2..9bc5b4f 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -91,7 +91,8 @@ enum { FLUSH_PENDING_TIMEOUT = 5 * HZ, }; -static bool blk_kick_flush(struct request_queue *q); +static bool blk_kick_flush(struct request_queue *q, + struct blk_flush_queue *fq); static unsigned int blk_flush_policy(unsigned int fflags, struct request *rq) { @@ -148,6 +149,7 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front) /** * blk_flush_complete_seq - complete flush sequence * @rq: FLUSH/FUA request being sequenced + * @fq: flush queue * @seq: sequences to complete (mask of %REQ_FSEQ_*, can be zero) * @error: whether an error occurred * @@ -160,11 +162,11 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front) * RETURNS: * %true if requests were added to the dispatch queue, %false otherwise. */ -static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, - int error) +static bool blk_flush_complete_seq(struct request *rq, + struct blk_flush_queue *fq, + unsigned int seq, int error) { struct request_queue *q = rq->q; - struct blk_flush_queue *fq = blk_get_flush_queue(q); struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; bool queued = false, kicked; @@ -210,7 +212,7 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, BUG(); } - kicked = blk_kick_flush(q); + kicked = blk_kick_flush(q, fq); return kicked | queued; } @@ -242,7 +244,7 @@ static void flush_end_io(struct request *flush_rq, int error) unsigned int seq = blk_flush_cur_seq(rq); BUG_ON(seq != REQ_FSEQ_PREFLUSH && seq != REQ_FSEQ_POSTFLUSH); - queued |= blk_flush_complete_seq(rq, seq, error); + queued |= blk_flush_complete_seq(rq, fq, seq, error); } /* @@ -268,6 +270,7 @@ static void flush_end_io(struct request *flush_rq, int error) /** * blk_kick_flush - consider issuing flush request * @q: request_queue being kicked + * @fq: flush queue * * Flush related states of @q have changed, consider issuing flush request. * Please read the comment at the top of this file for more info. @@ -278,9 +281,8 @@ static void flush_end_io(struct request *flush_rq, int error) * RETURNS: * %true if flush was issued, %false otherwise. */ -static bool blk_kick_flush(struct request_queue *q) +static bool blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq) { - struct blk_flush_queue *fq = blk_get_flush_queue(q); struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; struct request *first_rq = list_first_entry(pending, struct request, flush.list); @@ -317,12 +319,13 @@ static bool blk_kick_flush(struct request_queue *q) static void flush_data_end_io(struct request *rq, int error) { struct request_queue *q = rq->q; + struct blk_flush_queue *fq = blk_get_flush_queue(q); /* * After populating an empty queue, kick it to avoid stall. Read * the comment in flush_end_io(). */ - if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error)) + if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error)) blk_run_queue_async(q); } @@ -342,7 +345,7 @@ static void mq_flush_data_end_io(struct request *rq, int error) * the comment in flush_end_io(). */ spin_lock_irqsave(&fq->mq_flush_lock, flags); - if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error)) + if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error)) blk_mq_run_hw_queue(hctx, true); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); } @@ -364,6 +367,7 @@ void blk_insert_flush(struct request *rq) struct request_queue *q = rq->q; unsigned int fflags = q->flush_flags; /* may change, cache */ unsigned int policy = blk_flush_policy(fflags, rq); + struct blk_flush_queue *fq = blk_get_flush_queue(q); /* * @policy now records what operations need to be done. Adjust @@ -412,18 +416,16 @@ void blk_insert_flush(struct request *rq) rq->cmd_flags |= REQ_FLUSH_SEQ; rq->flush.saved_end_io = rq->end_io; /* Usually NULL */ if (q->mq_ops) { - struct blk_flush_queue *fq = blk_get_flush_queue(q); - rq->end_io = mq_flush_data_end_io; spin_lock_irq(&fq->mq_flush_lock); - blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0); + blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0); spin_unlock_irq(&fq->mq_flush_lock); return; } rq->end_io = flush_data_end_io; - blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0); + blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0); } /** -- cgit v1.1 From e97c293cdf77263abdc021de280516e0017afc84 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:46 +0800 Subject: block: introduce 'blk_mq_ctx' parameter to blk_get_flush_queue This patch adds 'blk_mq_ctx' parameter to blk_get_flush_queue(), so that this function can find the corresponding blk_flush_queue bound with current mq context since the flush queue will become per hw-queue. For legacy queue, the parameter can be simply 'NULL'. For multiqueue case, the parameter should be set as the context from which the related request is originated. With this context info, the hw queue and related flush queue can be found easily. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index 9bc5b4f..004d95e 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -223,7 +223,7 @@ static void flush_end_io(struct request *flush_rq, int error) bool queued = false; struct request *rq, *n; unsigned long flags = 0; - struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx); if (q->mq_ops) { spin_lock_irqsave(&fq->mq_flush_lock, flags); @@ -319,7 +319,7 @@ static bool blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq) static void flush_data_end_io(struct request *rq, int error) { struct request_queue *q = rq->q; - struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL); /* * After populating an empty queue, kick it to avoid stall. Read @@ -333,11 +333,10 @@ static void mq_flush_data_end_io(struct request *rq, int error) { struct request_queue *q = rq->q; struct blk_mq_hw_ctx *hctx; - struct blk_mq_ctx *ctx; + struct blk_mq_ctx *ctx = rq->mq_ctx; unsigned long flags; - struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct blk_flush_queue *fq = blk_get_flush_queue(q, ctx); - ctx = rq->mq_ctx; hctx = q->mq_ops->map_queue(q, ctx->cpu); /* @@ -367,7 +366,7 @@ void blk_insert_flush(struct request *rq) struct request_queue *q = rq->q; unsigned int fflags = q->flush_flags; /* may change, cache */ unsigned int policy = blk_flush_policy(fflags, rq); - struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct blk_flush_queue *fq = blk_get_flush_queue(q, rq->mq_ctx); /* * @policy now records what operations need to be done. Adjust -- cgit v1.1 From f70ced09170761acb69840cafaace4abc72cba4b Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:47 +0800 Subject: blk-mq: support per-distpatch_queue flush machinery This patch supports to run one single flush machinery for each blk-mq dispatch queue, so that: - current init_request and exit_request callbacks can cover flush request too, then the buggy copying way of initializing flush request's pdu can be fixed - flushing performance gets improved in case of multi hw-queue In fio sync write test over virtio-blk(4 hw queues, ioengine=sync, iodepth=64, numjobs=4, bs=4K), it is observed that througput gets increased a lot over my test environment: - throughput: +70% in case of virtio-blk over null_blk - throughput: +30% in case of virtio-blk over SSD image The multi virtqueue feature isn't merged to QEMU yet, and patches for the feature can be found in below tree: git://kernel.ubuntu.com/ming/qemu.git v2.1.0-mq.4 And simply passing 'num_queues=4 vectors=5' should be enough to enable multi queue(quad queue) feature for QEMU virtio-blk. Suggested-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index 004d95e..20badd7 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -305,8 +305,15 @@ static bool blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq) fq->flush_pending_idx ^= 1; blk_rq_init(q, flush_rq); - if (q->mq_ops) - blk_mq_clone_flush_request(flush_rq, first_rq); + + /* + * Borrow tag from the first request since they can't + * be in flight at the same time. + */ + if (q->mq_ops) { + flush_rq->mq_ctx = first_rq->mq_ctx; + flush_rq->tag = first_rq->tag; + } flush_rq->cmd_type = REQ_TYPE_FS; flush_rq->cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ; @@ -480,22 +487,22 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, } EXPORT_SYMBOL(blkdev_issue_flush); -struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q) +struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, + int node, int cmd_size) { struct blk_flush_queue *fq; int rq_sz = sizeof(struct request); - fq = kzalloc(sizeof(*fq), GFP_KERNEL); + fq = kzalloc_node(sizeof(*fq), GFP_KERNEL, node); if (!fq) goto fail; if (q->mq_ops) { spin_lock_init(&fq->mq_flush_lock); - rq_sz = round_up(rq_sz + q->tag_set->cmd_size, - cache_line_size()); + rq_sz = round_up(rq_sz + cmd_size, cache_line_size()); } - fq->flush_rq = kzalloc(rq_sz, GFP_KERNEL); + fq->flush_rq = kzalloc_node(rq_sz, GFP_KERNEL, node); if (!fq->flush_rq) goto fail_rq; -- cgit v1.1