mirror_zfs/module
Alexander Motin 86706441a8
Introduce write-mostly sums
wmsum counters are a reduced version of aggsum counters, optimized for
write-mostly scenarios.  They do not provide optimized read functions,
but instead allow much cheaper add function.  The primary usage is
infrequently read statistic counters, not requiring exact precision.

The Linux implementation is directly mapped into percpu_counter KPI.
The FreeBSD implementation is directly mapped into counter(9) KPI.
In user-space due to lack of better implementation mapped to aggsum.

Unfortunately neither Linux percpu_counter nor FreeBSD counter(9)
provide sufficient functionality to completelly replace aggsum, so
it still remains to be used for several hot counters.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #12114
2021-05-27 14:27:29 -06:00
..
avl Fix various typos 2021-04-02 18:52:15 -07:00
icp Replace ZoL with OpenZFS where applicable 2021-05-07 17:20:37 -07:00
lua cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
nvpair Links in Source Files 2020-09-02 09:42:12 -07:00
os Bend zpl_set_acl to permit the new userns* parameter 2021-05-27 08:55:49 -07:00
spl Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
unicode Fix various typos 2021-04-02 18:52:15 -07:00
zcommon libzfs: add keylocation=https://, backed by fetch(3) or libcurl 2021-05-12 21:21:35 -07:00
zfs Introduce write-mostly sums 2021-05-27 14:27:29 -06:00
zstd Fix various typos 2021-04-02 18:52:15 -07:00
.gitignore Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
Kbuild.in Add zstd support to zfs 2020-08-20 10:30:06 -07:00
Makefile.bsd Restore FreeBSD resource usage accounting 2021-02-19 22:34:33 -08:00
Makefile.in FreeBSD module --enable-debug --enable-invariants 2021-03-05 12:16:41 -08:00