This patch fixes q->unplug_thresh condition check in

__elv_add_request().  rq.count[READ] + rq.count[WRITE] can increase
more than one if another thread has allocated a request after the
current request is allocated or in_flight could have changed resulting
in larger-than-one change of nrq, thus breaking the threshold
mechanism.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Tejun Heo <htejun@gmail.com>
This commit is contained in:
Tejun Heo 2005-06-16 12:57:31 +02:00 committed by Jens Axboe
parent 9c56187d3c
commit c374f127e4

View file

@ -317,7 +317,7 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
int nrq = q->rq.count[READ] + q->rq.count[WRITE]
- q->in_flight;
if (nrq == q->unplug_thresh)
if (nrq >= q->unplug_thresh)
__generic_unplug_device(q);
}
} else