@@ -186,7 +186,7 @@ void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
int diff = limit - inflight;
if (!inflight || diff >= rwb->wb_background / 2)
- wake_up_all(&rqw->wait);
+ wake_up(&rqw->wait);
}
}
@@ -533,30 +533,6 @@ static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
return limit;
}
-static inline bool may_queue(struct rq_wb *rwb, struct rq_wait *rqw,
- wait_queue_entry_t *wait, unsigned long rw)
-{
- /*
- * inc it here even if disabled, since we'll dec it at completion.
- * this only happens if the task was sleeping in __wbt_wait(),
- * and someone turned it off at the same time.
- */
- if (!rwb_enabled(rwb)) {
- atomic_inc(&rqw->inflight);
- return true;
- }
-
- /*
- * If the waitqueue is already active and we are not the next
- * in line to be woken up, wait for our turn.
- */
- if (waitqueue_active(&rqw->wait) &&
- rqw->wait.head.next != &wait->entry)
- return false;
-
- return atomic_inc_below(&rqw->inflight, get_limit(rwb, rw));
-}
-
/*
* Block if we will exceed our limit, or if we are currently waiting for
* the timer to kick off queuing again.
@@ -567,16 +543,32 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
__acquires(lock)
{
struct rq_wait *rqw = get_rq_wait(rwb, wb_acct);
- DEFINE_WAIT(wait);
+ DECLARE_WAITQUEUE(wait, current);
+
+ /*
+ * inc it here even if disabled, since we'll dec it at completion.
+ * this only happens if the task was sleeping in __wbt_wait(),
+ * and someone turned it off at the same time.
+ */
+ if (!rwb_enabled(rwb)) {
+ atomic_inc(&rqw->inflight);
+ return;
+ }
- if (may_queue(rwb, rqw, &wait, rw))
+ if (!waitqueue_active(&rqw->wait)
+ && atomic_inc_below(&rqw->inflight, get_limit(rwb, rw)))
return;
+ add_wait_queue_exclusive(&rqw->wait, &wait);
do {
- prepare_to_wait_exclusive(&rqw->wait, &wait,
- TASK_UNINTERRUPTIBLE);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+
+ if (!rwb_enabled(rwb)) {
+ atomic_inc(&rqw->inflight);
+ break;
+ }
- if (may_queue(rwb, rqw, &wait, rw))
+ if (atomic_inc_below(&rqw->inflight, get_limit(rwb, rw)))
break;
if (lock) {
@@ -587,7 +579,8 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
io_schedule();
} while (1);
- finish_wait(&rqw->wait, &wait);
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&rqw->wait, &wait);
}
static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio)