mirror_zfs/module
Tom Caputi 7ad0ae91d5 Allow empty ds_props_obj to be destroyed
Currently, 'zfs list' and 'zfs get' commands can be slow when
working with snapshots that have a ds_props_obj. This is
because the code that discovers all of the properties for these
snapshots needs to read this object for each snapshot, which
almost always ends up causing an extra random synchronous read
for each snapshot. This performance penalty exists even if the
properties on that snapshot have been unset because the object
is normally only freed when the snapshot is freed, even though
it is only created when it is needed.

This patch allows the user to regain 'zfs list' performance on
these snapshots by destroying the ds_props_obj when it no longer
has any entries left. In practice on a production machine, this
optimization seems to make 'zfs list' about 55% faster.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #9704
2020-01-22 13:49:05 -08:00
..
avl Fix typos in module/ 2020-01-22 13:48:59 -08:00
icp Linux 5.0 compat: SIMD compatibility 2020-01-22 13:49:01 -08:00
lua Fix typos in module/ 2020-01-22 13:48:59 -08:00
nvpair Fix typos in module/ 2020-01-22 13:48:59 -08:00
spl Add missing documentation for some KMC flags 2020-01-22 13:49:04 -08:00
unicode Update build system and packaging 2018-05-29 16:00:33 -07:00
zcommon Increase allowed 'special_small_blocks' maximum value 2020-01-22 13:49:05 -08:00
zfs Allow empty ds_props_obj to be destroyed 2020-01-22 13:49:05 -08:00
.gitignore Adapt gitignore for modules 2020-01-22 13:49:05 -08:00
Makefile.in module/Makefile.in: don't run xargs if empty 2020-01-22 13:49:02 -08:00