c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2026-05-23 02:44:41 +03:00
Code Issues Packages Projects Releases Wiki Activity

Optimize small random numbers generation

Browse Source 
In all places except two spa_get_random() is used for small values,
and the consumers do not require well seeded high quality values.
Switch those two exceptions directly to random_get_pseudo_bytes()
and optimize spa_get_random(), renaming it to random_in_range(),
since it is not related to SPA or ZFS in general.

On FreeBSD directly map random_in_range() to new prng32_bounded() KPI
added in FreeBSD 13.  On Linux and in user-space just reduce the type
used to uint32_t to avoid more expensive 64bit division.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #12183
This commit is contained in:
Alexander Motin
2021-06-22 19:35:23 -04:00
committed by GitHub
parent ba91311561
commit 29274c9f6d
16 changed files with 83 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files
module/zfs/space_map.c
+1 -1
View File
@@ -726,7 +726,7 @@ space_map_write_impl(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
length > SM_RUN_MAX ||
vdev_id != SM_NO_VDEVID ||
(zfs_force_some_double_word_sm_entries &&
spa_get_random(100) == 0)))
random_in_range(100) == 0)))
words = 2;
space_map_write_seg(sm, rs_get_start(rs, rt), rs_get_end(rs,