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authorJens Axboe <axboe@fb.com>2014-05-20 11:49:02 -0600
committerJens Axboe <axboe@fb.com>2014-05-20 11:49:02 -0600
commite3a2b3f931f59d5284abd13faf8bded726884ffd (patch)
treef5426a4745996e95afc2f01f826e846710929dc2 /block/blk-core.c
parent64b14519e5913e8d4de9f2e5d9ef59abba3ed83d (diff)
downloadkernel-e3a2b3f931f59d5284abd13faf8bded726884ffd.tar.gz
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>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index a6bd3e702201..fe81e19099a1 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -848,6 +848,47 @@ static void freed_request(struct request_list *rl, unsigned int flags)
__freed_request(rl, sync ^ 1);
}
+int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
+{
+ struct request_list *rl;
+
+ spin_lock_irq(q->queue_lock);
+ q->nr_requests = nr;
+ blk_queue_congestion_threshold(q);
+
+ /* congestion isn't cgroup aware and follows root blkcg for now */
+ rl = &q->root_rl;
+
+ 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 0;
+}
+
/*
* Determine if elevator data should be initialized when allocating the
* request associated with @bio.