mirror_zfs/module
Brad Lewis 3ec34e5527 OpenZFS 9284 - arc_reclaim_thread has 2 jobs
Following the fix for 9018 (Replace kmem_cache_reap_now() with
kmem_cache_reap_soon), the arc_reclaim_thread() no longer blocks
while reaping.  However, the code is still confusing and error-prone,
because this thread has two responsibilities.  We should instead
separate this into two threads each with their own responsibility:

 1. keep `arc_size` under `arc_c`, by calling `arc_adjust()`, which
    improves `arc_is_overflowing()`

 2. keep enough free memory in the system, by calling
    `arc_kmem_reap_now()` plus `arc_shrink()`, which improves
    `arc_available_memory()`.

Furthermore, we can use the zthr infrastructure to separate the
"should we do something" from "do it" parts of the logic, and
normalize the start up / shut down of the threads.

Authored by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Tim Kordas <tim.kordas@joyent.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by:  Brad Lewis <brad.lewis@delphix.com>
Signed-off-by: Brad Lewis <brad.lewis@delphix.com>

OpenZFS-issue: https://www.illumos.org/issues/9284
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/de753e34f9
Closes #8165
2018-12-26 13:22:28 -08:00
..
avl Update build system and packaging 2018-05-29 16:00:33 -07:00
icp Fedora 28: Fix misc bounds check compiler warnings 2018-08-26 12:55:44 -07:00
lua Update build system and packaging 2018-05-29 16:00:33 -07:00
nvpair Add new fnvlist_lookup_* functions 2018-10-03 15:30:55 -07:00
spl OpenZFS 9284 - arc_reclaim_thread has 2 jobs 2018-12-26 13:22:28 -08:00
unicode Update build system and packaging 2018-05-29 16:00:33 -07:00
zcommon Fix 'zpool list -v' alignment 2018-12-04 10:17:54 -08:00
zfs OpenZFS 9284 - arc_reclaim_thread has 2 jobs 2018-12-26 13:22:28 -08:00
.gitignore Prepare SPL repo to merge with ZFS repo 2018-05-29 14:51:39 -07:00
Makefile.in Update build system and packaging 2018-05-29 16:00:33 -07:00