mirror_zfs/module
Alexander Motin 490c845efe
Compact dbuf/buf hashes and lock arrays
With default dbuf cache size of 1/32 of ARC, it makes no sense to have
hash table of the same size (or even bigger on Linux).  Reduce it to
1/8 of ARC's one, still leaving some slack, assuming higher I/O rate
via dbuf cache than via ARC.

Remove padding from ARC hash locks array.  The idea behind padding
is to avoid false sharing between locks.  It would have sense if
there would be a limited number of very busy locks.  But since we
have no limit on the number, using the same memory for more locks we
can achieve even lower lock contention with the same false sharing,
or we can use less memory for the same contention level.

Reduce number of hash locks from 8192 to 2048.  The number is still
big enough to not cause contention, but reduced memory size improves
cache hit rate for mutex_tryenter() in ARC eviction thread, saving
about 1% of the thread time.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #12289
2021-07-01 09:30:31 -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 Fix abd leak, kmem_free correct size of abd_t 2021-07-01 09:28:15 -06:00
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 Compact dbuf/buf hashes and lock arrays 2021-07-01 09:30:31 -06:00
zstd Fix build with KASAN 2021-06-25 22:28:12 -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