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authorJens Axboe <axboe@suse.de>2006-06-01 10:13:43 +0200
committerJens Axboe <axboe@suse.de>2006-06-01 10:13:43 +0200
commitae818a38d4755ba4c16a22a8eacec859511a5393 (patch)
tree923ec4b261ab8b633fff2be9e7b9c4afcf704737 /block
parent25776e3594f841b7fae7b33ebecf009a0a55bed1 (diff)
downloadlinux-linaro-stable-ae818a38d4755ba4c16a22a8eacec859511a5393.tar.gz
[PATCH] cfq-iosched: fix bug in timer handling for the idle class
There's a small window from when the timer is entered and we grab the queue lock, where cfq_set_active_queue() could be rearming the timer for us. Seen in the wild on a 12-way ppc box. Fix this by just using mod_timer(), which will do the right thing for us. Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'block')
-rw-r--r--block/cfq-iosched.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 5d2047b93eb5..85d188a30f82 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2193,10 +2193,9 @@ static void cfq_idle_class_timer(unsigned long data)
* race with a non-idle queue, reset timer
*/
end = cfqd->last_end_request + CFQ_IDLE_GRACE;
- if (!time_after_eq(jiffies, end)) {
- cfqd->idle_class_timer.expires = end;
- add_timer(&cfqd->idle_class_timer);
- } else
+ if (!time_after_eq(jiffies, end))
+ mod_timer(&cfqd->idle_class_timer, end);
+ else
cfq_schedule_dispatch(cfqd);
spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);