diff options
| author | Ming Lei <ming.lei@redhat.com> | 2020-09-11 18:41:14 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-09-11 05:26:19 -0600 |
| commit | 285008501c65a3fcee05d2c2c26cbf629ceff2f0 (patch) | |
| tree | c93edb67935d4dcde37c42660ea74eadce19fda5 | |
| parent | 84ed2573c5427de47c71a69d8b0a18020d5f6dd5 (diff) | |
blk-mq: always allow reserved allocation in hctx_may_queue
NVMe shares tagset between fabric queue and admin queue or between
connect_q and NS queue, so hctx_may_queue() can be called to allocate
request for these queues.
Tags can be reserved in these tagset. Before error recovery, there is
often lots of in-flight requests which can't be completed, and new
reserved request may be needed in error recovery path. However,
hctx_may_queue() can always return false because there is too many
in-flight requests which can't be completed during error handling.
Finally, nothing can proceed.
Fix this issue by always allowing reserved tag allocation in
hctx_may_queue(). This is reasonable because reserved tags are supposed
to always be available.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: David Milburn <dmilburn@redhat.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-mq-tag.c | 3 | ||||
| -rw-r--r-- | block/blk-mq.c | 5 |
2 files changed, 5 insertions, 3 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index c31c4a0478a5..aacf10decdbd 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -76,7 +76,8 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt) { - if (!data->q->elevator && !hctx_may_queue(data->hctx, bt)) + if (!data->q->elevator && !(data->flags & BLK_MQ_REQ_RESERVED) && + !hctx_may_queue(data->hctx, bt)) return BLK_MQ_NO_TAG; if (data->shallow_depth) diff --git a/block/blk-mq.c b/block/blk-mq.c index 4abb71459f94..e04b759add75 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1105,10 +1105,11 @@ static bool __blk_mq_get_driver_tag(struct request *rq) if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { bt = rq->mq_hctx->tags->breserved_tags; tag_offset = 0; + } else { + if (!hctx_may_queue(rq->mq_hctx, bt)) + return false; } - if (!hctx_may_queue(rq->mq_hctx, bt)) - return false; tag = __sbitmap_queue_get(bt); if (tag == BLK_MQ_NO_TAG) return false; |