diff options
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 9568bf8dfe82..79745c6d8e15 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); } } |