On Thu, Jan 06 2005, Nick Piggin wrote:
No that's right... but between the prepare_to_wait and the io_schedule,
get_request takes the lock and checks nr_requests. I think we are safe?
It looks like it, yes you are right. But it looks to be needed a few
lines further down instead, though :-)
===== drivers/block/ll_rw_blk.c 1.281 vs edited =====
--- 1.281/drivers/block/ll_rw_blk.c 2004-12-01 09:13:57 +01:00
+++ edited/drivers/block/ll_rw_blk.c 2005-01-06 09:32:19 +01:00
@@ -1630,11 +1630,11 @@
if (rl->count[rw] < queue_congestion_off_threshold(q))
clear_queue_congested(q, rw);
if (rl->count[rw]+1 <= q->nr_requests) {
- smp_mb();
if (waitqueue_active(&rl->wait[rw]))
wake_up(&rl->wait[rw]);
blk_clear_queue_full(q, rw);
}
+ smp_mb();
if (unlikely(waitqueue_active(&rl->drain)) &&
!rl->count[READ] && !rl->count[WRITE])
wake_up(&rl->drain);