For now, we just trace plug for single queue device or drivers
provide .commit_rqs, and have not trace plug for multiple queues
device. But, unplug events will be recorded when call
blk_mq_flush_plug_list(). Then, trace events will be asymmetrical,
just have unplug and without plug.
This patch add trace plug and unplug for multiple queues device in
blk_mq_make_request(). After that, we can accurately trace plug and
unplug for multiple queues.
Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
---
block/blk-mq.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5486c7d8b408..4aa673a6d285 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1987,11 +1987,13 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
plug->rq_count--;
}
blk_add_rq_to_plug(plug, rq);
+ trace_block_plug(q);
blk_mq_put_ctx(data.ctx);
if (same_queue_rq) {
data.hctx = same_queue_rq->mq_hctx;
+ trace_block_unplug(q, 1, true);
blk_mq_try_issue_directly(data.hctx, same_queue_rq,
&cookie, false, true);
}
--
2.16.2.dirty
