From ff3b74b8e1675c802e09157a56c97ca38a659b9d Mon Sep 17 00:00:00 2001
From: Yufen Yu <yuyufen@huawei.com>
Date: Tue, 26 Mar 2019 21:19:25 +0800
Subject: [PATCH] blk-mq: add trace block plug and unplug for multiple queues
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.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/blk-mq.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f3b0d33bdf882..22074a1e37cd4 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2003,11 +2003,13 @@ 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);
}
--
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