Commit 63de428b authored by Aaron Carroll's avatar Aaron Carroll Committed by Jens Axboe

deadline-iosched: allow non-sequential batching

Deadline currently only batches sector-contiguous requests, so except
for a few circumstances (e.g. requests in a single direction), it is
essentially first come first served.  This is bad for throughput, so
change it to CSCAN, which means requests in a batch do not need to be
sequential and are issued in increasing sector order.
Signed-off-by: default avatarAaron Carroll <aaronc@gelato.unsw.edu.au>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 766ca442
...@@ -258,17 +258,9 @@ static int deadline_dispatch_requests(struct request_queue *q, int force) ...@@ -258,17 +258,9 @@ static int deadline_dispatch_requests(struct request_queue *q, int force)
else else
rq = dd->next_rq[READ]; rq = dd->next_rq[READ];
if (rq) { if (rq && dd->batching < dd->fifo_batch)
/* we have a "next request" */ /* we have a next request are still entitled to batch */
if (dd->last_sector != rq->sector)
/* end the batch on a non sequential request */
dd->batching += dd->fifo_batch;
if (dd->batching < dd->fifo_batch)
/* we are still entitled to batch */
goto dispatch_request; goto dispatch_request;
}
/* /*
* at this point we are not running a batch. select the appropriate * at this point we are not running a batch. select the appropriate
......
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