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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 | |
| parent | 9e49184c82e9ec3ab4d45f9ea5a17ccaf43869f0 (diff) | |
| download | linux-a68bbddba486020c9c74825ce90c4c1ec463e0e8.tar.bz2 | |
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>
| -rw-r--r-- | block/as-iosched.c | 6 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 6 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 2 |
3 files changed, 14 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)); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 86f77ef127f4..0cf3e619fb21 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -442,6 +442,7 @@ struct request_queue #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */ #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */ #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */ +#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ static inline int queue_is_locked(struct request_queue *q) { @@ -547,6 +548,7 @@ enum { #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) +#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) #define blk_queue_flushing(q) ((q)->ordseq) #define blk_queue_stackable(q) \ test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) |