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authorJens Axboe <jens.axboe@oracle.com>2008-09-24 13:03:33 +0200
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 08:56:19 +0200
commita68bbddba486020c9c74825ce90c4c1ec463e0e8 (patch)
treece0acea1e609185968310316d3d1ac6f730db983 /block/cfq-iosched.c
parent9e49184c82e9ec3ab4d45f9ea5a17ccaf43869f0 (diff)
downloadconfigs-a68bbddba486020c9c74825ce90c4c1ec463e0e8.tar.gz
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.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 494b6fdcb18..03a5953bb5d 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));