diff options
Diffstat (limited to 'lib/sbitmap.c')
| -rw-r--r-- | lib/sbitmap.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/lib/sbitmap.c b/lib/sbitmap.c index eca462cba398..bea7984f7987 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -571,13 +571,19 @@ static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq) for (i = 0; i < SBQ_WAIT_QUEUES; i++) { struct sbq_wait_state *ws = &sbq->ws[wake_index]; + /* + * Advance the index before checking the current queue. + * It improves fairness, by ensuring the queue doesn't + * need to be fully emptied before trying to wake up + * from the next one. + */ + wake_index = sbq_index_inc(wake_index); + if (waitqueue_active(&ws->wait)) { if (wake_index != atomic_read(&sbq->wake_index)) atomic_set(&sbq->wake_index, wake_index); return ws; } - - wake_index = sbq_index_inc(wake_index); } return NULL; |