| Message ID | 20200923013339.1621784-9-ming.lei@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | blk-mq/scsi: tracking device queue depth via sbitmap | expand |
On 9/23/20 3:33 AM, Ming Lei wrote: > SCSI uses one global atomic variable to track queue depth for each > LUN/request queue. > > This way doesn't scale well when there is lots of CPU cores and the > disk is very fast. It has been observed that IOPS is affected a lot > by tracking queue depth via sdev->device_busy in IO path. > > Return budget token from .get_budget callback, and the budget token > can be passed to driver, so that we can replace the atomic variable > with sbitmap_queue, then the scale issue can be fixed. > > Cc: Omar Sandoval <osandov@fb.com> > Cc: Kashyap Desai <kashyap.desai@broadcom.com> > Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com> > Cc: Ewan D. Milne <emilne@redhat.com> > Cc: Hannes Reinecke <hare@suse.de> > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-mq-sched.c | 17 +++++++++++++---- > block/blk-mq.c | 36 +++++++++++++++++++++++++----------- > block/blk-mq.h | 25 +++++++++++++++++++++---- > drivers/scsi/scsi_lib.c | 16 +++++++++++----- > include/linux/blk-mq.h | 4 ++-- > 5 files changed, 72 insertions(+), 26 deletions(-) > > diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c > index 3e9596738852..1c04a58c5f99 100644 > --- a/block/blk-mq-sched.c > +++ b/block/blk-mq-sched.c > @@ -131,6 +131,7 @@ static int __blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) > > do { > struct request *rq; > + int budget_token; > > if (e->type->ops.has_work && !e->type->ops.has_work(hctx)) > break; > @@ -140,12 +141,13 @@ static int __blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) > break; > } > > - if (!blk_mq_get_dispatch_budget(q)) > + budget_token = blk_mq_get_dispatch_budget(q); > + if (budget_token < 0) > break; > > rq = e->type->ops.dispatch_request(hctx); > if (!rq) { > - blk_mq_put_dispatch_budget(q); > + blk_mq_put_dispatch_budget(q, budget_token); > /* > * We're releasing without dispatching. Holding the > * budget could have blocked any "hctx"s with the > @@ -157,6 +159,8 @@ static int __blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) > break; > } > > + blk_mq_set_rq_budget_token(rq, budget_token); > + > /* > * Now this rq owns the budget which has to be released > * if this rq won't be queued to driver via .queue_rq() > @@ -230,6 +234,8 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) > struct request *rq; > > do { > + int budget_token; > + > if (!list_empty_careful(&hctx->dispatch)) { > ret = -EAGAIN; > break; > @@ -238,12 +244,13 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) > if (!sbitmap_any_bit_set(&hctx->ctx_map)) > break; > > - if (!blk_mq_get_dispatch_budget(q)) > + budget_token = blk_mq_get_dispatch_budget(q); > + if (budget_token < 0) > break; > > rq = blk_mq_dequeue_from_ctx(hctx, ctx); > if (!rq) { > - blk_mq_put_dispatch_budget(q); > + blk_mq_put_dispatch_budget(q, budget_token); > /* > * We're releasing without dispatching. Holding the > * budget could have blocked any "hctx"s with the > @@ -255,6 +262,8 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) > break; > } > > + blk_mq_set_rq_budget_token(rq, budget_token); > + > /* > * Now this rq owns the budget which has to be released > * if this rq won't be queued to driver via .queue_rq() > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 88154cea83d8..7743cacb02b4 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1296,10 +1296,15 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, > bool need_budget) > { > struct blk_mq_hw_ctx *hctx = rq->mq_hctx; > + int budget_token = -1; > > - if (need_budget && !blk_mq_get_dispatch_budget(rq->q)) { > - blk_mq_put_driver_tag(rq); > - return PREP_DISPATCH_NO_BUDGET; > + if (need_budget) { > + budget_token = blk_mq_get_dispatch_budget(rq->q); > + if (budget_token < 0) { > + blk_mq_put_driver_tag(rq); > + return PREP_DISPATCH_NO_BUDGET; > + } > + blk_mq_set_rq_budget_token(rq, budget_token); > } > > if (!blk_mq_get_driver_tag(rq)) { > @@ -1316,7 +1321,7 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, > * together during handling partial dispatch > */ > if (need_budget) > - blk_mq_put_dispatch_budget(rq->q); > + blk_mq_put_dispatch_budget(rq->q, budget_token); > return PREP_DISPATCH_NO_TAG; > } > } > @@ -1326,12 +1331,16 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, > > /* release all allocated budgets before calling to blk_mq_dispatch_rq_list */ > static void blk_mq_release_budgets(struct request_queue *q, > - unsigned int nr_budgets) > + struct list_head *list) > { > - int i; > + struct request *rq; > > - for (i = 0; i < nr_budgets; i++) > - blk_mq_put_dispatch_budget(q); > + list_for_each_entry(rq, list, queuelist) { > + int budget_token = blk_mq_get_rq_budget_token(rq); > + > + if (budget_token >= 0) > + blk_mq_put_dispatch_budget(q, budget_token); > + } > } > > /* > @@ -1424,7 +1433,8 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, > (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED); > bool no_budget_avail = prep == PREP_DISPATCH_NO_BUDGET; > > - blk_mq_release_budgets(q, nr_budgets); > + if (nr_budgets) > + blk_mq_release_budgets(q, list); > > /* > * If we didn't flush the entire list, we could have told > @@ -1997,6 +2007,7 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > { > struct request_queue *q = rq->q; > bool run_queue = true; > + int budget_token; > > /* > * RCU or SRCU read lock is needed before checking quiesced flag. > @@ -2014,11 +2025,14 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > if (q->elevator && !bypass_insert) > goto insert; > > - if (!blk_mq_get_dispatch_budget(q)) > + budget_token = blk_mq_get_dispatch_budget(q); > + if (budget_token < 0) > goto insert; > > + blk_mq_set_rq_budget_token(rq, budget_token); > + > if (!blk_mq_get_driver_tag(rq)) { > - blk_mq_put_dispatch_budget(q); > + blk_mq_put_dispatch_budget(q, budget_token); > goto insert; > } > > diff --git a/block/blk-mq.h b/block/blk-mq.h > index a52703c98b77..bb59a3e54c3b 100644 > --- a/block/blk-mq.h > +++ b/block/blk-mq.h > @@ -186,17 +186,34 @@ unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part); > void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, > unsigned int inflight[2]); > > -static inline void blk_mq_put_dispatch_budget(struct request_queue *q) > +static inline void blk_mq_put_dispatch_budget(struct request_queue *q, > + int budget_token) > { > if (q->mq_ops->put_budget) > - q->mq_ops->put_budget(q); > + q->mq_ops->put_budget(q, budget_token); > } > > -static inline bool blk_mq_get_dispatch_budget(struct request_queue *q) > +static inline int blk_mq_get_dispatch_budget(struct request_queue *q) > { > if (q->mq_ops->get_budget) > return q->mq_ops->get_budget(q); > - return true; > + return 0; > +} > + > +static inline void blk_mq_set_rq_budget_token(struct request *rq, int token) > +{ > + if (token < 0) > + return; > + > + if (rq->q->mq_ops->set_rq_budget_token) > + rq->q->mq_ops->set_rq_budget_token(rq, token); > +} > + > +static inline int blk_mq_get_rq_budget_token(struct request *rq) > +{ > + if (rq->q->mq_ops->get_rq_budget_token) > + return rq->q->mq_ops->get_rq_budget_token(rq); > + return -1; > } > > static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index bfcccc73fd01..41380e200925 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -343,6 +343,7 @@ void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd) > atomic_dec(&starget->target_busy); > > atomic_dec(&sdev->device_busy); > + cmd->budget_token = -1; > } > > static void scsi_kick_queue(struct request_queue *q) > @@ -1128,6 +1129,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) > unsigned long jiffies_at_alloc; > int retries, to_clear; > bool in_flight; > + int budget_token = cmd->budget_token; > > if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) { > flags |= SCMD_INITIALIZED; > @@ -1156,6 +1158,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) > cmd->retries = retries; > if (in_flight) > __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); > + cmd->budget_token = budget_token; > > } > > @@ -1618,19 +1621,19 @@ static void scsi_mq_done(struct scsi_cmnd *cmd) > blk_mq_complete_request(cmd->request); > } > > -static void scsi_mq_put_budget(struct request_queue *q) > +static void scsi_mq_put_budget(struct request_queue *q, int budget_token) > { > struct scsi_device *sdev = q->queuedata; > > atomic_dec(&sdev->device_busy); > } > > -static bool scsi_mq_get_budget(struct request_queue *q) > +static int scsi_mq_get_budget(struct request_queue *q) > { > struct scsi_device *sdev = q->queuedata; > > if (scsi_dev_queue_ready(q, sdev)) > - return true; > + return 0; > > atomic_inc(&sdev->restarts); > > @@ -1652,7 +1655,7 @@ static bool scsi_mq_get_budget(struct request_queue *q) > if (unlikely(atomic_read(&sdev->device_busy) == 0 && > !scsi_device_blocked(sdev))) > blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY); > - return false; > + return -1; > } > > static void scsi_mq_set_rq_budget_token(struct request *req, int token) > @@ -1680,6 +1683,8 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, > blk_status_t ret; > int reason; > > + WARN_ON_ONCE(cmd->budget_token < 0); > + > /* > * If the device is not in running state we will reject some or all > * commands. > @@ -1730,7 +1735,8 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, > if (scsi_target(sdev)->can_queue > 0) > atomic_dec(&scsi_target(sdev)->target_busy); > out_put_budget: > - scsi_mq_put_budget(q); > + scsi_mq_put_budget(q, cmd->budget_token); > + cmd->budget_token = -1; > switch (ret) { > case BLK_STS_OK: > break; > diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h > index 71060c6a84b1..7b4d4b23403a 100644 > --- a/include/linux/blk-mq.h > +++ b/include/linux/blk-mq.h > @@ -307,12 +307,12 @@ struct blk_mq_ops { > * reserved budget. Also we have to handle failure case > * of .get_budget for avoiding I/O deadlock. > */ > - bool (*get_budget)(struct request_queue *); > + int (*get_budget)(struct request_queue *); > > /** > * @put_budget: Release the reserved budget. > */ > - void (*put_budget)(struct request_queue *); > + void (*put_budget)(struct request_queue *, int); > > /* > * @set_rq_budget_toekn: store rq's budget token > In principle, yes. But I would like to have some more clarification about the values the 'budget_token' can have. From what I gather -1 means 'no budget', but what exactly is the difference between '0' and, say, '5'? And indeed I would prefer to have the budget token to be unsigned, such that '0' means 'no budget', and any positive number would indicate the budget itself. Can we have a bit more documentation here? Cheers, Hannes
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 3e9596738852..1c04a58c5f99 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -131,6 +131,7 @@ static int __blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) do { struct request *rq; + int budget_token; if (e->type->ops.has_work && !e->type->ops.has_work(hctx)) break; @@ -140,12 +141,13 @@ static int __blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) break; } - if (!blk_mq_get_dispatch_budget(q)) + budget_token = blk_mq_get_dispatch_budget(q); + if (budget_token < 0) break; rq = e->type->ops.dispatch_request(hctx); if (!rq) { - blk_mq_put_dispatch_budget(q); + blk_mq_put_dispatch_budget(q, budget_token); /* * We're releasing without dispatching. Holding the * budget could have blocked any "hctx"s with the @@ -157,6 +159,8 @@ static int __blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) break; } + blk_mq_set_rq_budget_token(rq, budget_token); + /* * Now this rq owns the budget which has to be released * if this rq won't be queued to driver via .queue_rq() @@ -230,6 +234,8 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) struct request *rq; do { + int budget_token; + if (!list_empty_careful(&hctx->dispatch)) { ret = -EAGAIN; break; @@ -238,12 +244,13 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) if (!sbitmap_any_bit_set(&hctx->ctx_map)) break; - if (!blk_mq_get_dispatch_budget(q)) + budget_token = blk_mq_get_dispatch_budget(q); + if (budget_token < 0) break; rq = blk_mq_dequeue_from_ctx(hctx, ctx); if (!rq) { - blk_mq_put_dispatch_budget(q); + blk_mq_put_dispatch_budget(q, budget_token); /* * We're releasing without dispatching. Holding the * budget could have blocked any "hctx"s with the @@ -255,6 +262,8 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) break; } + blk_mq_set_rq_budget_token(rq, budget_token); + /* * Now this rq owns the budget which has to be released * if this rq won't be queued to driver via .queue_rq() diff --git a/block/blk-mq.c b/block/blk-mq.c index 88154cea83d8..7743cacb02b4 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1296,10 +1296,15 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, bool need_budget) { struct blk_mq_hw_ctx *hctx = rq->mq_hctx; + int budget_token = -1; - if (need_budget && !blk_mq_get_dispatch_budget(rq->q)) { - blk_mq_put_driver_tag(rq); - return PREP_DISPATCH_NO_BUDGET; + if (need_budget) { + budget_token = blk_mq_get_dispatch_budget(rq->q); + if (budget_token < 0) { + blk_mq_put_driver_tag(rq); + return PREP_DISPATCH_NO_BUDGET; + } + blk_mq_set_rq_budget_token(rq, budget_token); } if (!blk_mq_get_driver_tag(rq)) { @@ -1316,7 +1321,7 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, * together during handling partial dispatch */ if (need_budget) - blk_mq_put_dispatch_budget(rq->q); + blk_mq_put_dispatch_budget(rq->q, budget_token); return PREP_DISPATCH_NO_TAG; } } @@ -1326,12 +1331,16 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, /* release all allocated budgets before calling to blk_mq_dispatch_rq_list */ static void blk_mq_release_budgets(struct request_queue *q, - unsigned int nr_budgets) + struct list_head *list) { - int i; + struct request *rq; - for (i = 0; i < nr_budgets; i++) - blk_mq_put_dispatch_budget(q); + list_for_each_entry(rq, list, queuelist) { + int budget_token = blk_mq_get_rq_budget_token(rq); + + if (budget_token >= 0) + blk_mq_put_dispatch_budget(q, budget_token); + } } /* @@ -1424,7 +1433,8 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED); bool no_budget_avail = prep == PREP_DISPATCH_NO_BUDGET; - blk_mq_release_budgets(q, nr_budgets); + if (nr_budgets) + blk_mq_release_budgets(q, list); /* * If we didn't flush the entire list, we could have told @@ -1997,6 +2007,7 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, { struct request_queue *q = rq->q; bool run_queue = true; + int budget_token; /* * RCU or SRCU read lock is needed before checking quiesced flag. @@ -2014,11 +2025,14 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, if (q->elevator && !bypass_insert) goto insert; - if (!blk_mq_get_dispatch_budget(q)) + budget_token = blk_mq_get_dispatch_budget(q); + if (budget_token < 0) goto insert; + blk_mq_set_rq_budget_token(rq, budget_token); + if (!blk_mq_get_driver_tag(rq)) { - blk_mq_put_dispatch_budget(q); + blk_mq_put_dispatch_budget(q, budget_token); goto insert; } diff --git a/block/blk-mq.h b/block/blk-mq.h index a52703c98b77..bb59a3e54c3b 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -186,17 +186,34 @@ unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part); void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, unsigned int inflight[2]); -static inline void blk_mq_put_dispatch_budget(struct request_queue *q) +static inline void blk_mq_put_dispatch_budget(struct request_queue *q, + int budget_token) { if (q->mq_ops->put_budget) - q->mq_ops->put_budget(q); + q->mq_ops->put_budget(q, budget_token); } -static inline bool blk_mq_get_dispatch_budget(struct request_queue *q) +static inline int blk_mq_get_dispatch_budget(struct request_queue *q) { if (q->mq_ops->get_budget) return q->mq_ops->get_budget(q); - return true; + return 0; +} + +static inline void blk_mq_set_rq_budget_token(struct request *rq, int token) +{ + if (token < 0) + return; + + if (rq->q->mq_ops->set_rq_budget_token) + rq->q->mq_ops->set_rq_budget_token(rq, token); +} + +static inline int blk_mq_get_rq_budget_token(struct request *rq) +{ + if (rq->q->mq_ops->get_rq_budget_token) + return rq->q->mq_ops->get_rq_budget_token(rq); + return -1; } static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index bfcccc73fd01..41380e200925 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -343,6 +343,7 @@ void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd) atomic_dec(&starget->target_busy); atomic_dec(&sdev->device_busy); + cmd->budget_token = -1; } static void scsi_kick_queue(struct request_queue *q) @@ -1128,6 +1129,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) unsigned long jiffies_at_alloc; int retries, to_clear; bool in_flight; + int budget_token = cmd->budget_token; if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) { flags |= SCMD_INITIALIZED; @@ -1156,6 +1158,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) cmd->retries = retries; if (in_flight) __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); + cmd->budget_token = budget_token; } @@ -1618,19 +1621,19 @@ static void scsi_mq_done(struct scsi_cmnd *cmd) blk_mq_complete_request(cmd->request); } -static void scsi_mq_put_budget(struct request_queue *q) +static void scsi_mq_put_budget(struct request_queue *q, int budget_token) { struct scsi_device *sdev = q->queuedata; atomic_dec(&sdev->device_busy); } -static bool scsi_mq_get_budget(struct request_queue *q) +static int scsi_mq_get_budget(struct request_queue *q) { struct scsi_device *sdev = q->queuedata; if (scsi_dev_queue_ready(q, sdev)) - return true; + return 0; atomic_inc(&sdev->restarts); @@ -1652,7 +1655,7 @@ static bool scsi_mq_get_budget(struct request_queue *q) if (unlikely(atomic_read(&sdev->device_busy) == 0 && !scsi_device_blocked(sdev))) blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY); - return false; + return -1; } static void scsi_mq_set_rq_budget_token(struct request *req, int token) @@ -1680,6 +1683,8 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, blk_status_t ret; int reason; + WARN_ON_ONCE(cmd->budget_token < 0); + /* * If the device is not in running state we will reject some or all * commands. @@ -1730,7 +1735,8 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, if (scsi_target(sdev)->can_queue > 0) atomic_dec(&scsi_target(sdev)->target_busy); out_put_budget: - scsi_mq_put_budget(q); + scsi_mq_put_budget(q, cmd->budget_token); + cmd->budget_token = -1; switch (ret) { case BLK_STS_OK: break; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 71060c6a84b1..7b4d4b23403a 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -307,12 +307,12 @@ struct blk_mq_ops { * reserved budget. Also we have to handle failure case * of .get_budget for avoiding I/O deadlock. */ - bool (*get_budget)(struct request_queue *); + int (*get_budget)(struct request_queue *); /** * @put_budget: Release the reserved budget. */ - void (*put_budget)(struct request_queue *); + void (*put_budget)(struct request_queue *, int); /* * @set_rq_budget_toekn: store rq's budget token
SCSI uses one global atomic variable to track queue depth for each LUN/request queue. This way doesn't scale well when there is lots of CPU cores and the disk is very fast. It has been observed that IOPS is affected a lot by tracking queue depth via sdev->device_busy in IO path. Return budget token from .get_budget callback, and the budget token can be passed to driver, so that we can replace the atomic variable with sbitmap_queue, then the scale issue can be fixed. Cc: Omar Sandoval <osandov@fb.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com> Cc: Ewan D. Milne <emilne@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/blk-mq-sched.c | 17 +++++++++++++---- block/blk-mq.c | 36 +++++++++++++++++++++++++----------- block/blk-mq.h | 25 +++++++++++++++++++++---- drivers/scsi/scsi_lib.c | 16 +++++++++++----- include/linux/blk-mq.h | 4 ++-- 5 files changed, 72 insertions(+), 26 deletions(-)