commit b70c864d3ce706571d2f3cac1d35d4fba01d6072
author Oleg Nesterov <oleg@tv-sign.ru> Wed Nov 07 09:46:13 2007 +0100
committer Jens Axboe <jens.axboe@oracle.com> Wed Nov 07 09:46:13 2007 +0100
tree fbdab2c4ddf484e5344b8cc00e4bc24b6e443191
parent 2389d1ef172fc9df01f58265a436919d233fbc27

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>