diff options
| author | Tejun Heo <tj@kernel.org> | 2019-08-28 15:05:57 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-08-28 21:17:10 -0600 |
| commit | 6f816b4b746c2241540e537682d30d8e9997d674 (patch) | |
| tree | 367f6fc02a7f8605cb19fd71f683d69bd96fab98 /block/Kconfig | |
| parent | beab17fc2a507e85dd18b3cef83820c5770c5f34 (diff) | |
blk-mq: add optional request->alloc_time_ns
There are currently two start time timestamps - start_time_ns and
io_start_time_ns. The former marks the request allocation and and the
second issue-to-device time. The planned io.weight controller needs
to measure the total time bios take to execute after it leaves rq_qos
including the time spent waiting for request to become available,
which can easily dominate on saturated devices.
This patch adds request->alloc_time_ns which records when the request
allocation attempt started. As it isn't used for the usual stats,
make it optional behind CONFIG_BLK_RQ_ALLOC_TIME and
QUEUE_FLAG_RQ_ALLOC_TIME so that it can be compiled out when there are
no users and it's active only on queues which need it even when
compiled in.
v2: s/pre_start_time/alloc_time/ and add CONFIG_BLK_RQ_ALLOC_TIME
gating as suggested by Jens.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/Kconfig')
| -rw-r--r-- | block/Kconfig | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/block/Kconfig b/block/Kconfig index 8b5f8e560eb4..1b62ad6d0e12 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -26,6 +26,9 @@ menuconfig BLOCK if BLOCK +config BLK_RQ_ALLOC_TIME + bool + config BLK_SCSI_REQUEST bool |