mirror_zfs/include
Alexander Motin e0ce98d57c
Reduce number of atomic_add() calls in aggsum
Previous code used 4 atomics to do aggsum_flush_bucket() and 2 more to
re-borrow after the flush.  But since asc_borrowed and asc_delta are
accessed only while holding asc_lock, it makes no any sense to modify
as_lower_bound and as_upper_bound in multiple steps.  Instead of that
the new code uses only 2 atomics in all the cases, one per as_*_bound
variable.  I think even that is overkill, simple atomic store and
load could be used here, since all modifications are done under the
as_lock, but there are no such primitives in ZFS code now.

While there, make borrow code consider previous borrow value, so that
on mixed request patterns reduce chance of needing to borrow again if
much larger request follows tiny one that needed borrow.

Also reduce as_numbuckets from uint64_t to u_int.  It makes no sense
to use so large division operation on every aggsum_add().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #9930
2020-02-06 13:21:06 -08:00
..
os Add AltiVec RAID-Z 2020-01-23 11:01:24 -08:00
sys Reduce number of atomic_add() calls in aggsum 2020-02-06 13:21:06 -08:00
.gitignore OpenZFS restructuring - move platform specific sources 2019-09-06 11:26:26 -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 Add 'zfs send --saved' flag 2020-01-10 10:16:58 -08:00
libzfs_impl.h Add FreeBSD jail support hooks 2019-12-11 11:58:37 -08:00
libzfs.h libzfs: add zfs_mount_at() function 2020-01-14 08:49:54 -08:00
libzutil.h Colorize zpool status output 2019-12-19 16:26:07 -08:00
Makefile.am OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
thread_pool.h Add libtpool (thread pools) 2017-08-09 15:31:08 -07:00
zfeature_common.h Disable EDONR on FreeBSD 2019-12-05 13:10:29 -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 Restrict filesystem creation if name referred either '.' or '..' 2019-06-13 08:56:15 -07:00
zfs_prop.h Add zfs module feature and property info to sysfs 2018-09-02 12:09:53 -07:00