Commit c374f127 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe

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: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
parent 9c56187d
...@@ -317,7 +317,7 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where, ...@@ -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] int nrq = q->rq.count[READ] + q->rq.count[WRITE]
- q->in_flight; - q->in_flight;
if (nrq == q->unplug_thresh) if (nrq >= q->unplug_thresh)
__generic_unplug_device(q); __generic_unplug_device(q);
} }
} else } else
......
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