path: root/block/blk-mq.h
diff options
authorJens Axboe <>2014-05-20 11:49:02 -0600
committerJens Axboe <>2014-05-20 11:49:02 -0600
commite3a2b3f931f59d5284abd13faf8bded726884ffd (patch)
treef5426a4745996e95afc2f01f826e846710929dc2 /block/blk-mq.h
parent64b14519e5913e8d4de9f2e5d9ef59abba3ed83d (diff)
blk-mq: allow changing of queue depth through sysfs
For request_fn based devices, the block layer exports a 'nr_requests' file through sysfs to allow adjusting of queue depth on the fly. Currently this returns -EINVAL for blk-mq, since it's not wired up. Wire this up for blk-mq, so that it now also always dynamic adjustments of the allowed queue depth for any given block device managed by blk-mq. Signed-off-by: Jens Axboe <>
Diffstat (limited to 'block/blk-mq.h')
1 files changed, 1 insertions, 0 deletions
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 5e5a378962b7..7db4fe4bd002 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -32,6 +32,7 @@ void blk_mq_drain_queue(struct request_queue *q);
void blk_mq_free_queue(struct request_queue *q);
void blk_mq_clone_flush_request(struct request *flush_rq,
struct request *orig_rq);
+int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
* CPU hotplug helpers