diff options
| author | Gabriel Krisman Bertazi <krisman@collabora.com> | 2020-10-06 15:41:25 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-10-06 14:36:35 -0600 |
| commit | a926c7afffcc0f2e35e6acbccb16921bacf34617 (patch) | |
| tree | 78fbeb9355c7c93de719759f878813c4a72a3845 /block | |
| parent | eda5cc997abd21054085486c9dee3fee269f3592 (diff) | |
block: Consider only dispatched requests for inflight statistic
According to Documentation/block/stat.rst, inflight should not include
I/O requests that are in the queue but not yet dispatched to the device,
but blk-mq identifies as inflight any request that has a tag allocated,
which, for queues without elevator, happens at request allocation time
and before it is queued in the ctx (default case in blk_mq_submit_bio).
In addition, current behavior is different for queues with elevator from
queues without it, since for the former the driver tag is allocated at
dispatch time. A more precise approach would be to only consider
requests with state MQ_RQ_IN_FLIGHT.
This effectively reverts commit 6131837b1de6 ("blk-mq: count allocated
but not started requests in iostats inflight") to consolidate blk-mq
behavior with itself (elevator case) and with original documentation,
but it differs from the behavior used by the legacy path.
This version differs from v1 by using blk_mq_rq_state to access the
state attribute. Avoid using blk_mq_request_started, which was
suggested, since we don't want to include MQ_RQ_COMPLETE.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 2e4b3cad2a61..c5fefd39d0c0 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -105,7 +105,7 @@ static bool blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx, { struct mq_inflight *mi = priv; - if (rq->part == mi->part) + if (rq->part == mi->part && blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) mi->inflight[rq_data_dir(rq)]++; return true; |