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authorKeith Busch <keith.busch@intel.com>2018-11-26 19:54:30 +0300
committerJens Axboe <axboe@kernel.dk>2018-11-26 20:34:27 +0300
commitaf78ff7c6e66832afcdf5418f67b11c409f9e7a1 (patch)
tree22b7a66b3c246d2793180f31ffa062f6cea74e37
parentf1342709d18af97b0e71449d5696b8873d1a456c (diff)
downloadlinux-af78ff7c6e66832afcdf5418f67b11c409f9e7a1.tar.xz
blk-mq: Simplify request completion state
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. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-mq.c4
-rw-r--r--include/linux/blk-mq.h14
2 files changed, 1 insertions, 17 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7c8cfa0cd420..cda698804422 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 6e3da356a8eb..b8de11e0603b 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -329,20 +329,6 @@ 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.