Commit c374f127 authored Jun 16, 2005 by Tejun Heo Committed by Jens Axboe Jun 16, 2005

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>

parent 9c56187d

drivers/block/elevator.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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

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