c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2026-05-24 19:28:53 +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/vdev_indirect.c
+2 -2
View File
@@ -1572,7 +1572,7 @@ vdev_indirect_splits_enumerate_randomly(indirect_vsd_t *iv, zio_t *zio)
indirect_child_t *ic = list_head(&is->is_unique_child);
int children = is->is_unique_children;
for (int i = spa_get_random(children); i > 0; i--)
for (int i = random_in_range(children); i > 0; i--)
ic = list_next(&is->is_unique_child, ic);
ASSERT3P(ic, !=, NULL);
@@ -1736,7 +1736,7 @@ vdev_indirect_reconstruct_io_done(zio_t *zio)
* Known_good will be TRUE when reconstruction is known to be possible.
*/
if (zfs_reconstruct_indirect_damage_fraction != 0 &&
spa_get_random(zfs_reconstruct_indirect_damage_fraction) == 0)
random_in_range(zfs_reconstruct_indirect_damage_fraction) == 0)
known_good = (vdev_indirect_splits_damage(iv, zio) == 0);
/*