diff options
Diffstat (limited to 'block/blk-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 590d1ef2f961..59685918167e 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -468,6 +468,9 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page, else if (val >= 0) val *= 1000ULL; + if (wbt_get_min_lat(q) == val) + return count; + /* * Ensure that the queue is idled, in case the latency update * ends up either enabling or disabling wbt completely. We can't @@ -817,21 +820,16 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head) } /** - * __blk_release_queue - release a request queue when it is no longer needed + * __blk_release_queue - release a request queue * @work: pointer to the release_work member of the request queue to be released * * Description: - * blk_release_queue is the counterpart of blk_init_queue(). It should be - * called when a request queue is being released; typically when a block - * device is being de-registered. Its primary task it to free the queue - * itself. - * - * Notes: - * The low level driver must have finished any outstanding requests first - * via blk_cleanup_queue(). - * - * Although blk_release_queue() may be called with preemption disabled, - * __blk_release_queue() may sleep. + * This function is called when a block device is being unregistered. The + * process of releasing a request queue starts with blk_cleanup_queue, which + * set the appropriate flags and then calls blk_put_queue, that decrements + * the reference counter of the request queue. Once the reference counter + * of the request queue reaches zero, blk_release_queue is called to release + * all allocated resources of the request queue. */ static void __blk_release_queue(struct work_struct *work) { |