mirror_zfs/include
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
..
os FreeBSD: fix compilation of FreeBSD world after 29274c9f6 2021-06-25 10:28:51 -07:00
sys Compact dbuf/buf hashes and lock arrays 2021-07-01 09:30:31 -06:00
.gitignore OpenZFS restructuring - move platform specific sources 2019-09-06 11:26:26 -07:00
cityhash.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
libnvpair.h lib{efi,avl,share,tpool,zfs_core,zfsbootenv,zutil}: -fvisibility=hidden 2021-06-09 17:04:32 -07:00
libuutil_common.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil_impl.h libuutil: purge unused functions 2021-04-12 09:32:43 -07:00
libuutil.h libuutil: purge unused functions 2021-04-12 09:32:43 -07:00
libzfs_core.h lib{efi,avl,share,tpool,zfs_core,zfsbootenv,zutil}: -fvisibility=hidden 2021-06-09 17:04:32 -07:00
libzfs.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
libzfsbootenv.h lib{efi,avl,share,tpool,zfs_core,zfsbootenv,zutil}: -fvisibility=hidden 2021-06-09 17:04:32 -07:00
libzutil.h libzutil: add zfs_{base,dir}name() 2021-06-11 09:10:05 -07:00
Makefile.am libzfs: don't distribute libzfs_impl.h 2021-06-03 13:17:35 -07:00
thread_pool.h lib{efi,avl,share,tpool,zfs_core,zfsbootenv,zutil}: -fvisibility=hidden 2021-06-09 17:04:32 -07:00
zfeature_common.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
zfs_comutil.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
zfs_deleg.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
zfs_fletcher.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
zfs_namecheck.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
zfs_prop.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00