diff options
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 9568bf8dfe82..e285152345a2 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -401,7 +401,6 @@ static void check_scale_change(struct iolatency_grp *iolat) unsigned int cur_cookie; unsigned int our_cookie = atomic_read(&iolat->scale_cookie); u64 scale_lat; - unsigned int old; int direction = 0; if (lat_to_blkg(iolat)->parent == NULL) @@ -422,11 +421,10 @@ static void check_scale_change(struct iolatency_grp *iolat) else return; - old = atomic_cmpxchg(&iolat->scale_cookie, our_cookie, cur_cookie); - - /* Somebody beat us to the punch, just bail. */ - if (old != our_cookie) + if (!atomic_try_cmpxchg(&iolat->scale_cookie, &our_cookie, cur_cookie)) { + /* Somebody beat us to the punch, just bail. */ return; + } if (direction < 0 && iolat->min_lat_nsec) { u64 samples_thresh; @@ -633,8 +631,8 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio) window_start = atomic64_read(&iolat->window_start); if (now > window_start && (now - window_start) >= iolat->cur_win_nsec) { - if (atomic64_cmpxchg(&iolat->window_start, - window_start, now) == window_start) + if (atomic64_try_cmpxchg(&iolat->window_start, + &window_start, now)) iolatency_check_latencies(iolat, now); } } @@ -773,19 +771,23 @@ int blk_iolatency_init(struct request_queue *q) rqos->ops = &blkcg_iolatency_ops; rqos->q = q; - rq_qos_add(q, rqos); - + ret = rq_qos_add(q, rqos); + if (ret) + goto err_free; ret = blkcg_activate_policy(q, &blkcg_policy_iolatency); - if (ret) { - rq_qos_del(q, rqos); - kfree(blkiolat); - return ret; - } + if (ret) + goto err_qos_del; timer_setup(&blkiolat->timer, blkiolatency_timer_fn, 0); INIT_WORK(&blkiolat->enable_work, blkiolatency_enable_work_fn); return 0; + +err_qos_del: + rq_qos_del(q, rqos); +err_free: + kfree(blkiolat); + return ret; } static void iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val) |