diff options
| author | Jens Axboe <axboe@fb.com> | 2017-01-26 22:42:34 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-01-27 16:20:34 +0100 |
| commit | 50e1dab86aa2c10cbca2f754aae9542169403141 (patch) | |
| tree | 2e17cd0d604bf63d82e4f8838b57ec579690ca52 /block/blk-mq-sched.h | |
| parent | blk-mq: release driver tag on a requeue event (diff) | |
| download | linux-50e1dab86aa2c10cbca2f754aae9542169403141.tar.xz linux-50e1dab86aa2c10cbca2f754aae9542169403141.zip | |
blk-mq-sched: fix starvation for multiple hardware queues and shared tags
If we have both multiple hardware queues and shared tag map between
devices, we need to ensure that we propagate the hardware queue
restart bit higher up. This is because we can get into a situation
where we don't have any IO pending on a hardware queue, yet we fail
getting a tag to start new IO. If that happens, it's not enough to
mark the hardware queue as needing a restart, we need to bubble
that up to the higher level queue as well.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Tested-by: Hannes Reinecke <hare@suse.com>
Diffstat (limited to 'block/blk-mq-sched.h')
| -rw-r--r-- | block/blk-mq-sched.h | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 6b465bc7014c..becbc7840364 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -19,6 +19,7 @@ bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, struct request *rq); bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio); bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio); bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq); +void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx); void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx); void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, @@ -123,11 +124,6 @@ blk_mq_sched_completed_request(struct blk_mq_hw_ctx *hctx, struct request *rq) BUG_ON(rq->internal_tag == -1); blk_mq_put_tag(hctx, hctx->sched_tags, rq->mq_ctx, rq->internal_tag); - - if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { - clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); - blk_mq_run_hw_queue(hctx, true); - } } static inline void blk_mq_sched_started_request(struct request *rq) @@ -160,8 +156,15 @@ static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx) static inline void blk_mq_sched_mark_restart(struct blk_mq_hw_ctx *hctx) { - if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) + if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); + if (hctx->flags & BLK_MQ_F_TAG_SHARED) { + struct request_queue *q = hctx->queue; + + if (!test_bit(QUEUE_FLAG_RESTART, &q->queue_flags)) + set_bit(QUEUE_FLAG_RESTART, &q->queue_flags); + } + } } static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx) |