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 <axboe@fb.com>
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 7500f87..4d6811a 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -48,11 +48,10 @@
static ssize_t
queue_requests_store(struct request_queue *q, const char *page, size_t count)
{
- struct request_list *rl;
unsigned long nr;
- int ret;
+ int ret, err;
- if (!q->request_fn)
+ if (!q->request_fn && !q->mq_ops)
return -EINVAL;
ret = queue_var_store(&nr, page, count);
@@ -62,40 +61,14 @@
if (nr < BLKDEV_MIN_RQ)
nr = BLKDEV_MIN_RQ;
- spin_lock_irq(q->queue_lock);
- q->nr_requests = nr;
- blk_queue_congestion_threshold(q);
+ if (q->request_fn)
+ err = blk_update_nr_requests(q, nr);
+ else
+ err = blk_mq_update_nr_requests(q, nr);
- /* congestion isn't cgroup aware and follows root blkcg for now */
- rl = &q->root_rl;
+ if (err)
+ return err;
- if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
- blk_set_queue_congested(q, BLK_RW_SYNC);
- else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
- blk_clear_queue_congested(q, BLK_RW_SYNC);
-
- if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
- blk_set_queue_congested(q, BLK_RW_ASYNC);
- else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
- blk_clear_queue_congested(q, BLK_RW_ASYNC);
-
- blk_queue_for_each_rl(rl, q) {
- if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
- blk_set_rl_full(rl, BLK_RW_SYNC);
- } else {
- blk_clear_rl_full(rl, BLK_RW_SYNC);
- wake_up(&rl->wait[BLK_RW_SYNC]);
- }
-
- if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
- blk_set_rl_full(rl, BLK_RW_ASYNC);
- } else {
- blk_clear_rl_full(rl, BLK_RW_ASYNC);
- wake_up(&rl->wait[BLK_RW_ASYNC]);
- }
- }
-
- spin_unlock_irq(q->queue_lock);
return ret;
}