blk-mq: get rid of manual run of queue with __blk_mq_run_hw_queue()
Two cases:
1) blk_mq_alloc_request() needlessly re-runs the queue, after
calling into the tag allocation without NOWAIT set. We don't
need to do that.
2) blk_mq_map_request() should just use blk_mq_run_hw_queue() with
the async flag set to false.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e0a69da..c297000 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -34,8 +34,6 @@
static DEFINE_MUTEX(all_q_mutex);
static LIST_HEAD(all_q_list);
-static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx);
-
/*
* Check if any of the ctx's have pending work in this hardware queue
*/
@@ -228,19 +226,9 @@
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
-
rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
- if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) {
- __blk_mq_run_hw_queue(hctx);
- blk_mq_put_ctx(ctx);
-
- ctx = blk_mq_get_ctx(q);
- hctx = q->mq_ops->map_queue(q, ctx->cpu);
- blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
- rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
- ctx = alloc_data.ctx;
- }
blk_mq_put_ctx(ctx);
+
if (!rq) {
blk_queue_exit(q);
return ERR_PTR(-EWOULDBLOCK);
@@ -1225,7 +1213,7 @@
blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx);
rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
if (unlikely(!rq)) {
- __blk_mq_run_hw_queue(hctx);
+ blk_mq_run_hw_queue(hctx, false);
blk_mq_put_ctx(ctx);
trace_block_sleeprq(q, bio, op);