[BLOCK] elevator switch fixes/cleanup

- 100msec sleep is a little excessive, lots of requests can complete
  in that timeframe. Use 10msec instead.
- Rename QUEUE_FLAG_BYPASS to QUEUE_FLAG_ELVSWITCH to indicate what
  is going on.

Signed-off-by: Jens Axboe <axboe@suse.de>
This commit is contained in:
Jens Axboe 2005-10-28 08:30:39 +02:00 committed by Jens Axboe
parent cb98fc8bb9
commit 64521d1a3b
3 changed files with 6 additions and 6 deletions

View File

@ -671,14 +671,14 @@ static void elevator_switch(request_queue_t *q, struct elevator_type *new_e)
*/
spin_lock_irq(q->queue_lock);
set_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);
set_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
while (q->elevator->ops->elevator_dispatch_fn(q, 1))
;
while (q->rq.elvpriv) {
spin_unlock_irq(q->queue_lock);
msleep(100);
msleep(10);
spin_lock_irq(q->queue_lock);
}
@ -703,7 +703,7 @@ static void elevator_switch(request_queue_t *q, struct elevator_type *new_e)
* finally exit old elevator and turn off BYPASS.
*/
elevator_exit(old_elevator);
clear_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);
clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
return;
fail_register:
@ -716,7 +716,7 @@ fail_register:
fail:
q->elevator = old_elevator;
elv_register_queue(q);
clear_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);
clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
kfree(e);
error:
elevator_put(new_e);

View File

@ -1940,7 +1940,7 @@ get_rq:
if (rl->count[rw] >= queue_congestion_on_threshold(q))
set_queue_congested(q, rw);
priv = !test_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);
priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
if (priv)
rl->elvpriv++;

View File

@ -442,7 +442,7 @@ enum {
#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
#define QUEUE_FLAG_BYPASS 8 /* don't use elevator, just do FIFO */
#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
#define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)