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| author | Jens Axboe <axboe@fb.com> | 2015-11-24 15:58:53 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-11-24 15:58:53 -0700 |
| commit | 3b627a3f934c493ada71217f14681e5157e95783 (patch) | |
| tree | 930a9fd9f1161a949385d6af04a4b94ae3794327 | |
| parent | bd5cecea43ef379e82250addd0303e2f9ede6793 (diff) | |
| download | linux-3b627a3f934c493ada71217f14681e5157e95783.tar.gz linux-3b627a3f934c493ada71217f14681e5157e95783.tar.bz2 linux-3b627a3f934c493ada71217f14681e5157e95783.zip | |
block: clarify blk_add_timer() use case for blk-mq
Just a comment update on not needing queue_lock, and that we aren't
really adding the request to a timeout list for !mq.
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | block/blk-timeout.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/block/blk-timeout.c b/block/blk-timeout.c index aa40aa93381b..3610af561748 100644 --- a/block/blk-timeout.c +++ b/block/blk-timeout.c @@ -186,6 +186,7 @@ unsigned long blk_rq_timeout(unsigned long timeout) * Notes: * Each request has its own timer, and as it is added to the queue, we * set up the timer. When the request completes, we cancel the timer. + * Queue lock must be held for the non-mq case, mq case doesn't care. */ void blk_add_timer(struct request *req) { @@ -209,6 +210,11 @@ void blk_add_timer(struct request *req) req->timeout = q->rq_timeout; req->deadline = jiffies + req->timeout; + + /* + * Only the non-mq case needs to add the request to a protected list. + * For the mq case we simply scan the tag map. + */ if (!q->mq_ops) list_add_tail(&req->timeout_list, &req->q->timeout_list); |