]> git.baikalelectronics.ru Git - kernel.git/commit
cfq: fix IOPRIO_CLASS_IDLE delays
authorOleg Nesterov <oleg@tv-sign.ru>
Wed, 7 Nov 2007 08:46:13 +0000 (09:46 +0100)
committerJens Axboe <jens.axboe@oracle.com>
Wed, 7 Nov 2007 08:46:13 +0000 (09:46 +0100)
commit2dc90a49c2c29fe4ef912ead150b1f9ccb8576fa
treefbdab2c4ddf484e5344b8cc00e4bc24b6e443191
parentb99abd01e579e72a70f42a14123371c840c5d9c4
cfq: fix IOPRIO_CLASS_IDLE delays

After the fresh boot:

ionice -c3 -p $$
echo cfq >> /sys/block/XXX/queue/scheduler
dd if=/dev/XXX of=/dev/null bs=512 count=1

Now dd hangs in D state and the queue is completely stalled for approximately
INITIAL_JIFFIES + CFQ_IDLE_GRACE jiffies. This is because cfq_init_queue()
forgets to initialize cfq_data->last_end_request.

(I guess this patch is not complete, overflow is still possible)

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
block/cfq-iosched.c