diff options
| author | Jens Axboe <jens.axboe@oracle.com> | 2008-09-24 13:03:33 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-10-09 08:56:19 +0200 |
| commit | a68bbddba486020c9c74825ce90c4c1ec463e0e8 (patch) | |
| tree | ce0acea1e609185968310316d3d1ac6f730db983 /block/cfq-iosched.c | |
| parent | 9e49184c82e9ec3ab4d45f9ea5a17ccaf43869f0 (diff) | |
| download | lwn-a68bbddba486020c9c74825ce90c4c1ec463e0e8.tar.gz lwn-a68bbddba486020c9c74825ce90c4c1ec463e0e8.zip | |
block: add queue flag for SSD/non-rotational devices
We don't want to idle in AS/CFQ if the device doesn't have a seek
penalty. So add a QUEUE_FLAG_NONROT to indicate a non-rotational
device, low level drivers should set this flag upon discovery of
an SSD or similar device type.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 494b6fdcb183..03a5953bb5df 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -878,6 +878,12 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) struct cfq_io_context *cic; unsigned long sl; + /* + * SSD device without seek penalty, disable idling + */ + if (blk_queue_nonrot(cfqd->queue)) + return; + WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); WARN_ON(cfq_cfqq_slice_new(cfqq)); |