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| author | Jens Axboe <axboe@fb.com> | 2017-01-13 14:43:58 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-01-17 10:04:31 -0700 |
| commit | d34849913819a5e0cbfbe724dbe79df89278c524 (patch) | |
| tree | 71b427fa3b22b30dc2038448ec06936018adaee4 /block/blk-mq-sched.c | |
| parent | 945ffb60c11dfb228130f3f2bdde961cecb76671 (diff) | |
| download | lwn-d34849913819a5e0cbfbe724dbe79df89278c524.tar.gz lwn-d34849913819a5e0cbfbe724dbe79df89278c524.zip | |
blk-mq-sched: allow setting of default IO scheduler
Add Kconfig entries to manage what devices get assigned an MQ
scheduler, and add a blk-mq flag for drivers to opt out of scheduling.
The latter is useful for admin type queues that still allocate a blk-mq
queue and tag set, but aren't use for normal IO.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Diffstat (limited to 'block/blk-mq-sched.c')
| -rw-r--r-- | block/blk-mq-sched.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 26759798a0b3..d05061f27bb1 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -366,3 +366,23 @@ void blk_mq_sched_teardown(struct request_queue *q) queue_for_each_hw_ctx(q, hctx, i) blk_mq_sched_free_tags(set, hctx, i); } + +int blk_mq_sched_init(struct request_queue *q) +{ + int ret; + +#if defined(CONFIG_DEFAULT_SQ_NONE) + if (q->nr_hw_queues == 1) + return 0; +#endif +#if defined(CONFIG_DEFAULT_MQ_NONE) + if (q->nr_hw_queues > 1) + return 0; +#endif + + mutex_lock(&q->sysfs_lock); + ret = elevator_init(q, NULL); + mutex_unlock(&q->sysfs_lock); + + return ret; +} |