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authorJens Axboe <axboe@fb.com>2017-01-19 10:59:07 -0700
committerJens Axboe <axboe@fb.com>2017-01-20 09:05:53 -0700
commit70f36b6001bf596eb411c4b302e84c4824ae8730 (patch)
tree2ff2d5af758f0185f486bcdc0645986a4a9b204a /block/blk-mq.c
parent7e79dadce222e06e0c30a77280f3426014bee185 (diff)
downloadlwn-70f36b6001bf596eb411c4b302e84c4824ae8730.tar.gz
lwn-70f36b6001bf596eb411c4b302e84c4824ae8730.zip
blk-mq: allow resize of scheduler requests
Add support for growing the tags associated with a hardware queue, for the scheduler tags. Currently we only support resizing within the limits of the original depth, change that so we can grow it as well by allocating and replacing the existing scheduler tag set. This is similar to how we could increase the software queue depth with the legacy IO stack and schedulers. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b365cde4c909..ee69e5e89769 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2561,6 +2561,9 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
if (!set)
return -EINVAL;
+ blk_mq_freeze_queue(q);
+ blk_mq_quiesce_queue(q);
+
ret = 0;
queue_for_each_hw_ctx(q, hctx, i) {
if (!hctx->tags)
@@ -2569,11 +2572,14 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
* If we're using an MQ scheduler, just update the scheduler
* queue depth. This is similar to what the old code would do.
*/
- if (!hctx->sched_tags)
- ret = blk_mq_tag_update_depth(hctx->tags,
- min(nr, set->queue_depth));
- else
- ret = blk_mq_tag_update_depth(hctx->sched_tags, nr);
+ if (!hctx->sched_tags) {
+ ret = blk_mq_tag_update_depth(hctx, &hctx->tags,
+ min(nr, set->queue_depth),
+ false);
+ } else {
+ ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
+ nr, true);
+ }
if (ret)
break;
}
@@ -2581,6 +2587,9 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
if (!ret)
q->nr_requests = nr;
+ blk_mq_unfreeze_queue(q);
+ blk_mq_start_stopped_hw_queues(q, true);
+
return ret;
}