There are no more users relying on blk-mq request states to prevent
double completions, so replace the relatively expensive cmpxchg operation
with WRITE_ONCE.
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
---
block/blk-mq.c | 4 +---
include/linux/blk-mq.h | 14 --------------
2 files changed, 1 insertion(+), 17 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 03b1af0151ca..6c546a021803 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -568,9 +568,7 @@ static void __blk_mq_complete_request(struct request *rq)
bool shared = false;
int cpu;
- if (!blk_mq_mark_complete(rq))
- return;
-
+ WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
/*
* Most of single queue controllers, there is only one irq vector
* for handling IO completion, and the only irq's affinity is set
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index e32e9293e5a0..1a857c6e17fa 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -237,20 +237,6 @@ void blk_mq_quiesce_queue_nowait(struct request_queue *q);
unsigned int blk_mq_rq_cpu(struct request *rq);
-/**
- * blk_mq_mark_complete() - Set request state to complete
- * @rq: request to set to complete state
- *
- * Returns true if request state was successfully set to complete. If
- * successful, the caller is responsibile for seeing this request is ended, as
- * blk_mq_complete_request will not work again.
- */
-static inline bool blk_mq_mark_complete(struct request *rq)
-{
- return cmpxchg(&rq->state, MQ_RQ_IN_FLIGHT, MQ_RQ_COMPLETE) ==
- MQ_RQ_IN_FLIGHT;
-}
-
/*
* Driver command data is immediately after the request. So subtract request
* size to get back to the original request, add request size to get the PDU.
--
2.14.4
