mirror_zfs/module
Alexander Motin f8020c9363
Make metaslab class rotor and aliquot per-allocator.
Metaslab rotor and aliquot are used to distribute workload between
vdevs while keeping some locality for logically adjacent blocks.  Once
multiple allocators were introduced to separate allocation of different
objects it does not make much sense for different allocators to write
into different metaslabs of the same metaslab group (vdev) same time,
competing for its resources.  This change makes each allocator choose
metaslab group independently, colliding with others only sporadically.

Test including simultaneous write into 4 files with recordsize of 4KB
on a striped pool of 30 disks on a system with 40 logical cores show
reduction of vdev queue lock contention from 54 to 27% due to better
load distribution.  Unfortunately it won't help much ZVOLs yet since
only one dataset/ZVOL is synced at a time, and so for the most part
only one allocator is used, but it may improve later.

While there, to reduce the number of pointer dereferences change
per-allocator storage for metaslab classes and groups from several
separate malloc()'s to variable length arrays at the ends of the
original class and group structures.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes #11288
2020-12-15 10:55:44 -08:00
..
avl Links in Source Files 2020-09-02 09:42:12 -07:00
icp Introduce CPU_SEQID_UNSTABLE 2020-11-02 11:51:12 -08:00
lua lua: avoid gcc -Wreturn-local-addr bug 2020-12-15 09:20:48 -08:00
nvpair Links in Source Files 2020-09-02 09:42:12 -07:00
os FreeBSD: Fix format of vfs.zfs.arc_no_grow_shift 2020-12-10 15:28:56 -08:00
spl Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
unicode Throw const on some strings 2020-10-02 17:44:10 -07:00
zcommon FreeBSD: Implement sysctl for fletcher4 impl 2020-12-11 10:29:01 -08:00
zfs Make metaslab class rotor and aliquot per-allocator. 2020-12-15 10:55:44 -08:00
zstd Optimize locking checks in mempool allocator 2020-11-02 12:10:07 -08:00
.gitignore Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
Kbuild.in Add zstd support to zfs 2020-08-20 10:30:06 -07:00
Makefile.bsd FreeBSD: decouple ZFS_DEBUG from kernel debug settings 2020-11-24 09:16:46 -08:00
Makefile.in Fix Linux modules uninstall 2020-10-08 20:07:10 -07:00