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Gvozden Neskovic ee36c709c3 Performance optimization of AVL tree comparator functions
perf: 2.75x faster ddt_entry_compare()
    First 256bits of ddt_key_t is a block checksum, which are expected
to be close to random data. Hence, on average, comparison only needs to
look at first few bytes of the keys. To reduce number of conditional
jump instructions, the result is computed as: sign(memcmp(k1, k2)).

Sign of an integer 'a' can be obtained as: `(0 < a) - (a < 0)` := {-1, 0, 1} ,
which is computed efficiently.  Synthetic performance evaluation of
original and new algorithm over 1G random keys on 2.6GHz Intel(R) Xeon(R)
CPU E5-2660 v3:

old	6.85789 s
new	2.49089 s

perf: 2.8x faster vdev_queue_offset_compare() and vdev_queue_timestamp_compare()
    Compute the result directly instead of using conditionals

perf: zfs_range_compare()
    Speedup between 1.1x - 2.5x, depending on compiler version and
optimization level.

perf: spa_error_entry_compare()
    `bcmp()` is not suitable for comparator use. Use `memcmp()` instead.

perf: 2.8x faster metaslab_compare() and metaslab_rangesize_compare()
perf: 2.8x faster zil_bp_compare()
perf: 2.8x faster mze_compare()
perf: faster dbuf_compare()
perf: faster compares in spa_misc
perf: 2.8x faster layout_hash_compare()
perf: 2.8x faster space_reftree_compare()
perf: libzfs: faster avl tree comparators
perf: guid_compare()
perf: dsl_deadlist_compare()
perf: perm_set_compare()
perf: 2x faster range_tree_seg_compare()
perf: faster unique_compare()
perf: faster vdev_cache _compare()
perf: faster vdev_uberblock_compare()
perf: faster fuid _compare()
perf: faster zfs_znode_hold_compare()

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Richard Elling <richard.elling@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5033
2016-08-31 14:35:34 -07:00
cmd Fix zhack argument processing 2016-08-31 14:32:46 -07:00
config Linux compat: Grsecurity kernel 2016-08-22 10:05:45 -07:00
contrib Set proper dependency for string replacement targets 2016-08-02 10:28:29 -07:00
etc Set proper dependency for string replacement targets 2016-08-02 10:28:29 -07:00
include Performance optimization of AVL tree comparator functions 2016-08-31 14:35:34 -07:00
lib Performance optimization of AVL tree comparator functions 2016-08-31 14:35:34 -07:00
man Add zfs_arc_meta_limit_percent tunable 2016-08-23 13:03:01 -07:00
module Performance optimization of AVL tree comparator functions 2016-08-31 14:35:34 -07:00
rpm Add missing RPM BuildRequires 2016-05-23 10:33:42 -07:00
scripts zloop: print backtrace from core files 2016-07-25 11:47:21 -07:00
tests Fix zhack argument processing 2016-08-31 14:32:46 -07:00
udev Set proper dependency for string replacement targets 2016-08-02 10:28:29 -07:00
.gitignore Illumos Crypto Port module added to enable native encryption in zfs 2016-07-20 10:43:30 -07:00
.gitmodules Add zimport.sh compatibility test script 2014-02-21 12:10:31 -08:00
AUTHORS Add a missing > to AUTHORS 2014-09-02 14:18:53 -07:00
autogen.sh build: do not call boilerplate ourself 2013-04-02 10:55:20 -07:00
configure.ac OpenZFS 5997 - FRU field not set during pool creation and never updated 2016-08-12 13:06:48 -07:00
copy-builtin Illumos Crypto Port module added to enable native encryption in zfs 2016-07-20 10:43:30 -07:00
COPYRIGHT Update ZED copyright boilerplate 2015-05-11 15:07:00 -07:00
DISCLAIMER Fix minor typos and update marketing copy. 2013-03-21 12:51:06 -07:00
Makefile.am Add make lint target 2016-08-02 09:25:43 -07:00
META Tag zfs-0.6.5 2015-09-11 11:16:38 -07:00
OPENSOLARIS.LICENSE Add CDDL license file 2008-12-01 14:49:34 -08:00
README.markdown Fix minor typos and update marketing copy. 2013-03-21 12:51:06 -07:00
TEST Add the ZFS Test Suite 2016-03-16 13:46:16 -07:00
zfs-script-config.sh.in Illumos Crypto Port module added to enable native encryption in zfs 2016-07-20 10:43:30 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

Native ZFS for Linux!

ZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the Illumos community.

ZFS on Linux, which is also known as ZoL, is currently feature complete. It includes fully functional and stable SPA, DMU, ZVOL, and ZPL layers.

Full documentation for installing ZoL on your favorite Linux distribution can be found at: http://zfsonlinux.org