Commit Graph

10 Commits

Author SHA1 Message Date
Joe Thornber be500ed721 dm space maps: improve performance with inc/dec on ranges of blocks
When we break sharing on btree nodes we typically need to increment
the reference counts to every value held in the node.  This can
cause a lot of repeated calls to the space maps.  Fix this by changing
the interface to the space map inc/dec methods to take ranges of
adjacent blocks to be operated on.

For installations that are using a lot of snapshots this will reduce
cpu overhead of fundamental operations such as provisioning a new block,
or deleting a snapshot, by as much as 10 times.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-06-04 12:07:22 -04:00
Joe Thornber 9b696229aa dm persistent data: add cursor skip functions to the cursor APIs
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-02-16 13:12:50 -05:00
Bart Van Assche 0637018dff dm array: remove a dead assignment in populate_ablock_with_values()
A value is assigned to 'nr_entries' but is never used, remove it.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:09 -05:00
Joe Thornber fdd1315aa5 dm array: introduce cursor api
More efficient way to iterate an array due to prefetching (makes use of
the new dm_btree_cursor_* api).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:15:04 -04:00
Joe Thornber dd6a77d998 dm array: add dm_array_new()
dm_array_new() creates a new, populated array more efficiently than
starting with an empty one and resizing.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:12:23 -04:00
Mikulas Patocka 4c7da06f5a dm persistent data: eliminate unnecessary return values
dm_bm_unlock and dm_tm_unlock return an integer value but the returned
value is always 0.  The calling code sometimes checks the return value
and sometimes doesn't.

Eliminate these unnecessary return values and also the checks for them.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-10-31 19:06:02 -04:00
Joe Thornber 8001e87d0e dm array: if resizing the array is a noop set the new root to the old one
This could've been quite bad (to return success but not update the new
root to point at the old) but in practice the only known consumer of the
dm array code is the DM cache target.  And the DM cache target passes in
the same old root to array_resize() anyway.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-12-01 11:30:07 -05:00
Joe Thornber ed9571f0cf dm array: fix a reference counting bug in shadow_ablock
An old array block could have its reference count decremented below
zero when it is being replaced in the btree by a new array block.

The fix is to increment the old ablock's reference count just before
inserting a new ablock into the btree.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-12-13 14:22:10 -05:00
Joe Thornber 9c1d4de560 dm array: fix bug in growing array
Entries would be lost if the old tail block was partially filled.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-11-05 11:20:50 -05:00
Joe Thornber 6513c29f44 dm persistent data: add transactional array
Add a transactional array.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00