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| 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 | |
| parent | floppy: support arbitrary first-sector numbers (diff) | |
| download | linux-a68bbddba486020c9c74825ce90c4c1ec463e0e8.tar.xz linux-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')
| -rw-r--r-- | block/as-iosched.c | 6 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c index 80af9257e64a..4c6fafbba933 100644 --- a/block/as-iosched.c +++ b/block/as-iosched.c @@ -745,6 +745,12 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) */ static int as_can_anticipate(struct as_data *ad, struct request *rq) { + /* + * SSD device without seek penalty, disable idling + */ + if (blk_queue_nonrot(ad->q)) + return 0; + if (!ad->io_context) /* * Last request submitted was a write 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)); |