diff options
| -rw-r--r-- | block/kyber-iosched.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c index b4df317c2916..f95c60774ce8 100644 --- a/block/kyber-iosched.c +++ b/block/kyber-iosched.c @@ -100,9 +100,13 @@ struct kyber_hctx_data { unsigned int cur_domain; unsigned int batching; wait_queue_entry_t domain_wait[KYBER_NUM_DOMAINS]; + struct sbq_wait_state *domain_ws[KYBER_NUM_DOMAINS]; atomic_t wait_index[KYBER_NUM_DOMAINS]; }; +static int kyber_domain_wake(wait_queue_entry_t *wait, unsigned mode, int flags, + void *key); + static int rq_sched_domain(const struct request *rq) { unsigned int op = rq->cmd_flags; @@ -385,6 +389,9 @@ static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) for (i = 0; i < KYBER_NUM_DOMAINS; i++) { INIT_LIST_HEAD(&khd->rqs[i]); + init_waitqueue_func_entry(&khd->domain_wait[i], + kyber_domain_wake); + khd->domain_wait[i].private = hctx; INIT_LIST_HEAD(&khd->domain_wait[i].entry); atomic_set(&khd->wait_index[i], 0); } @@ -524,35 +531,39 @@ static int kyber_get_domain_token(struct kyber_queue_data *kqd, int nr; nr = __sbitmap_queue_get(domain_tokens); - if (nr >= 0) - return nr; /* * If we failed to get a domain token, make sure the hardware queue is * run when one becomes available. Note that this is serialized on * khd->lock, but we still need to be careful about the waker. */ - if (list_empty_careful(&wait->entry)) { - init_waitqueue_func_entry(wait, kyber_domain_wake); - wait->private = hctx; + if (nr < 0 && list_empty_careful(&wait->entry)) { ws = sbq_wait_ptr(domain_tokens, &khd->wait_index[sched_domain]); + khd->domain_ws[sched_domain] = ws; add_wait_queue(&ws->wait, wait); /* * Try again in case a token was freed before we got on the wait - * queue. The waker may have already removed the entry from the - * wait queue, but list_del_init() is okay with that. + * queue. */ nr = __sbitmap_queue_get(domain_tokens); - if (nr >= 0) { - unsigned long flags; + } - spin_lock_irqsave(&ws->wait.lock, flags); - list_del_init(&wait->entry); - spin_unlock_irqrestore(&ws->wait.lock, flags); - } + /* + * If we got a token while we were on the wait queue, remove ourselves + * from the wait queue to ensure that all wake ups make forward + * progress. It's possible that the waker already deleted the entry + * between the !list_empty_careful() check and us grabbing the lock, but + * list_del_init() is okay with that. + */ + if (nr >= 0 && !list_empty_careful(&wait->entry)) { + ws = khd->domain_ws[sched_domain]; + spin_lock_irq(&ws->wait.lock); + list_del_init(&wait->entry); + spin_unlock_irq(&ws->wait.lock); } + return nr; } |