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| author | Aaron Carroll <aaronc@gelato.unsw.edu.au> | 2008-08-14 10:17:13 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-10-09 08:56:02 +0200 |
| commit | 63de428b139d3d31d86ebe25ae97b33f6540fb7e (patch) | |
| tree | def85c8e9990293effe71baf3b0dce648eab516c /block/deadline-iosched.c | |
| parent | virtio_blk: use a wrapper function to access io context information of IO req... (diff) | |
| download | linux-63de428b139d3d31d86ebe25ae97b33f6540fb7e.tar.xz linux-63de428b139d3d31d86ebe25ae97b33f6540fb7e.zip | |
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: Aaron Carroll <aaronc@gelato.unsw.edu.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/deadline-iosched.c')
| -rw-r--r-- | block/deadline-iosched.c | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index 342448c3d2dd..07b80e4642f9 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c @@ -258,17 +258,9 @@ static int deadline_dispatch_requests(struct request_queue *q, int force) else rq = dd->next_rq[READ]; - if (rq) { - /* we have a "next request" */ - - 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; - } + if (rq && dd->batching < dd->fifo_batch) + /* we have a next request are still entitled to batch */ + goto dispatch_request; /* * at this point we are not running a batch. select the appropriate |