mirror_zfs/include
Alexander Motin 15177c1aac 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>
Closes #12289
2021-09-14 12:22:46 -07:00
..
os Optimize small random numbers generation 2021-09-14 12:10:17 -07:00
sys Compact dbuf/buf hashes and lock arrays 2021-09-14 12:22:46 -07:00
.gitignore OpenZFS restructuring - move platform specific sources 2019-09-06 11:26:26 -07:00
cityhash.h Compile cityhash code into libzfs 2020-03-27 09:11:22 -07:00
libnvpair.h Add JSON output support to channel programs 2018-03-19 12:40:58 -07:00
libuutil_common.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil.h Correct cppcheck errors 2017-09-19 12:17:29 -07:00
libzfs_core.h zfs label bootenv should store data as nvlist 2020-09-15 15:42:27 -07:00
libzfs_impl.h Add 'zfs rename -u' to rename without remounting 2020-09-01 16:14:16 -07:00
libzfs.h Improvements to the 'compatibility' property 2021-04-14 13:23:08 -07:00
libzfsbootenv.h zfs label bootenv should store data as nvlist 2020-09-15 15:42:27 -07:00
libzutil.h Add prototypes 2020-06-18 12:21:32 -07:00
Makefile.am zfs label bootenv should store data as nvlist 2020-09-15 15:42:27 -07:00
thread_pool.h Add libtpool (thread pools) 2017-08-09 15:31:08 -07:00
zfeature_common.h FreeBSD: disable edonr in zfs_mod_supported_feature() 2021-02-17 08:14:51 -08:00
zfs_comutil.h Fix "zpool add -n" for dedup, special and log devices 2020-01-06 15:40:06 -08:00
zfs_deleg.h Remove code for zfs remap 2019-06-24 16:44:01 -07:00
zfs_fletcher.h Add AVX512BW variant of fletcher 2019-10-30 12:26:14 -07:00
zfs_namecheck.h Implement bookmark copying 2020-02-11 13:19:12 -08:00
zfs_prop.h Add zfs module feature and property info to sysfs 2018-09-02 12:09:53 -07:00