Messages in this thread Patch in this message | | | Date | Thu, 26 May 2011 14:23:21 -0400 | From | Mike Snitzer <> | Subject | Re: dm: pass up rotational flag |
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On Wed, May 25 2011 at 4:50pm -0400, Mandeep Singh Baines <msb@chromium.org> wrote:
> Allow the NONROT flag to be passed through to linear mappings if all > underlying device 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> > Cc: Neil Brown <neilb@suse.de> > Cc: Mike Snitzer <snitzer@redhat.com> > Cc: Jens Axboe <jaxboe@fusionio.com> > Cc: Martin K. Petersen <martin.petersen@oracle.com> > Cc: Alasdair G Kergon <agk@redhat.com> > Cc: dm-devel@redhat.com
Thanks for doing this, looks good in general.
Just a few small nits: - rename device_nonrot to device_is_nonrot - rename dm_table_all_nonrot to dm_table_is_nonrot - add missing whitespace in dm_table_set_restrictions - move ti declaration outside of dm_table_is_nonrot's while loop - dm doesn't use 'true' or 'false' bool returns even though we have functions that return bool -- odd but best to keep consistent for now
I'll respond with v2 that folds these changes in and my Signed-off-by --- drivers/md/dm-table.c | 18 ++++++++++-------- 1 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 40c6071..a173828 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1177,28 +1177,29 @@ static void dm_table_set_integrity(struct dm_table *t) blk_get_integrity(template_disk)); } -static int device_nonrot(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) +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_all_nonrot(struct dm_table *t) +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)) { - struct dm_target *ti = dm_table_get_target(t, i++); + ti = dm_table_get_target(t, i++); if (!ti->type->iterate_devices || - !ti->type->iterate_devices(ti, device_nonrot, NULL)) - return false; + !ti->type->iterate_devices(ti, device_is_nonrot, NULL)) + return 0; } - return true; + return 1; } void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, @@ -1213,7 +1214,8 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q); else queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); - if (!dm_table_all_nonrot(t)) + + if (!dm_table_is_nonrot(t)) queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q); else queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
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