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author | Jens Axboe <axboe@fb.com> | 2017-04-10 09:54:56 -0600 |
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committer | Jens Axboe <axboe@fb.com> | 2017-04-28 08:11:43 -0600 |
commit | 21c6e939a9f6bb06fe616a87defec0f92a7c3df0 (patch) | |
tree | 4313793669d17a93b634236023d5ad3cf1c5ee22 /include/linux | |
parent | 818cd1cbaa7b00bbc35452a76bebc681a65f1912 (diff) | |
download | op-kernel-dev-21c6e939a9f6bb06fe616a87defec0f92a7c3df0.zip op-kernel-dev-21c6e939a9f6bb06fe616a87defec0f92a7c3df0.tar.gz |
blk-mq: unify hctx delay_work and run_work
The only difference between ->run_work and ->delay_work, is that
the latter is used to defer running a queue. This is done by
marking the queue stopped, and scheduling ->delay_work to run
sometime in the future. While the queue is stopped, direct runs
or runs through ->run_work will not run the queue.
If we combine the handlers, then we need to handle two things:
1) If a delayed/stopped run is scheduled, then we should not run
the queue before that has been completed.
2) If a queue is delayed/stopped, the handler needs to restart
the queue. Normally a run of a queue with the stopped bit set
would be a no-op.
Case 1 is handled by modifying a currently pending queue run
to the deadline set by the caller of blk_mq_delay_queue().
Subsequent attempts to queue a queue run will find the work
item already pending, and direct runs will see a stopped queue
as before.
Case 2 is handled by adding a new bit, BLK_MQ_S_START_ON_RUN,
that tells the work handler that it should clear a stopped
queue and run the handler.
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/blk-mq.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index c7cc903..f3e5e1d 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -51,8 +51,6 @@ struct blk_mq_hw_ctx { atomic_t nr_active; - struct delayed_work delay_work; - struct hlist_node cpuhp_dead; struct kobject kobj; @@ -168,6 +166,7 @@ enum { BLK_MQ_S_TAG_ACTIVE = 1, BLK_MQ_S_SCHED_RESTART = 2, BLK_MQ_S_TAG_WAITING = 3, + BLK_MQ_S_START_ON_RUN = 4, BLK_MQ_MAX_DEPTH = 10240, |