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| author | Jens Axboe <axboe@fb.com> | 2017-01-26 14:42:34 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-01-27 08:20:34 -0700 |
| commit | 50e1dab86aa2c10cbca2f754aae9542169403141 (patch) | |
| tree | 2e17cd0d604bf63d82e4f8838b57ec579690ca52 /block/blk-mq.c | |
| parent | 99cf1dc580f0766825395aae4f60ec1d8438f011 (diff) | |
| download | lwn-50e1dab86aa2c10cbca2f754aae9542169403141.tar.gz lwn-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.c')
| -rw-r--r-- | block/blk-mq.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 711883384585..21795c6575bc 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -40,7 +40,7 @@ static LIST_HEAD(all_q_list); /* * Check if any of the ctx's have pending work in this hardware queue */ -static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) +bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) { return sbitmap_any_bit_set(&hctx->ctx_map) || !list_empty_careful(&hctx->dispatch) || @@ -345,6 +345,7 @@ void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); if (sched_tag != -1) blk_mq_sched_completed_request(hctx, rq); + blk_mq_sched_restart_queues(hctx); blk_queue_exit(q); } |