diff options
| author | Jens Axboe <axboe@fb.com> | 2016-11-28 09:22:47 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-11-28 10:27:03 -0700 |
| commit | 80e091d10e8bf7b801d634ea8870b9e907314424 (patch) | |
| tree | 05d99a001b158de7e3f6f9eb119f28bb226b8bc2 /block/blk-wbt.c | |
| parent | feffa5cc7b47f38210d4997ceb3fe30881d6c337 (diff) | |
blk-wbt: allow reset of default latency through sysfs
Allow a write of '-1' to reset the default latency target for
a given device. This removes knowledge of the different default
settings for rotational vs non-rotational from user space.
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-wbt.c')
| -rw-r--r-- | block/blk-wbt.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 9f97594e68ce..92df2f7c5af1 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -675,6 +675,18 @@ void wbt_disable(struct rq_wb *rwb) } EXPORT_SYMBOL_GPL(wbt_disable); +u64 wbt_default_latency_nsec(struct request_queue *q) +{ + /* + * We default to 2msec for non-rotational storage, and 75msec + * for rotational storage. + */ + if (blk_queue_nonrot(q)) + return 2000000ULL; + else + return 75000000ULL; +} + int wbt_init(struct request_queue *q) { struct rq_wb *rwb; @@ -711,10 +723,7 @@ int wbt_init(struct request_queue *q) q->rq_wb = rwb; blk_stat_enable(q); - if (blk_queue_nonrot(q)) - rwb->min_lat_nsec = 2000000ULL; - else - rwb->min_lat_nsec = 75000000ULL; + rwb->min_lat_nsec = wbt_default_latency_nsec(q); wbt_set_queue_depth(rwb, blk_queue_depth(q)); wbt_set_write_cache(rwb, test_bit(QUEUE_FLAG_WC, &q->queue_flags)); |