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| author | Mandeep Singh Baines <msb@chromium.org> | 2011-10-31 20:18:50 +0000 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2011-10-31 20:18:50 +0000 |
| commit | 4693c9668fdcec229825b3763876b4744f9e6d5e (patch) | |
| tree | 683d07005d06c3e25bbec25b910567275f0bb9d1 /drivers/md/dm-table.c | |
| parent | c3b92c8787367a8bb53d57d9789b558f1295cc96 (diff) | |
| download | linux-4693c9668fdcec229825b3763876b4744f9e6d5e.tar.gz linux-4693c9668fdcec229825b3763876b4744f9e6d5e.tar.bz2 linux-4693c9668fdcec229825b3763876b4744f9e6d5e.zip | |
dm table: propagate non rotational flag
Allow QUEUE_FLAG_NONROT to propagate up the device stack if all
underlying devices are non-rotational. Tools like ureadahead will
schedule IOs differently based on the rotational flag.
With this patch, I see boot time go from 7.75 s to 7.46 s on my device.
Suggested-by: J. Richard Barnette <jrbarnette@chromium.org>
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: dm-devel@redhat.com
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-table.c')
| -rw-r--r-- | drivers/md/dm-table.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index bc04518e9d8b..81cbbf375bd7 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1299,6 +1299,31 @@ static bool dm_table_discard_zeroes_data(struct dm_table *t) return 1; } +static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct request_queue *q = bdev_get_queue(dev->bdev); + + return q && blk_queue_nonrot(q); +} + +static bool dm_table_is_nonrot(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i = 0; + + /* Ensure that all underlying device are non-rotational. */ + while (i < dm_table_get_num_targets(t)) { + ti = dm_table_get_target(t, i++); + + if (!ti->type->iterate_devices || + !ti->type->iterate_devices(ti, device_is_nonrot, NULL)) + return 0; + } + + return 1; +} + void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { @@ -1324,6 +1349,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, if (!dm_table_discard_zeroes_data(t)) q->limits.discard_zeroes_data = 0; + if (dm_table_is_nonrot(t)) + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); + else + queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q); + dm_table_set_integrity(t); /* |