K 10 svn:author V 3 mav K 8 svn:date V 27 2018-07-30T19:44:14.932731Z K 7 svn:log V 1251 9284 arc_reclaim_thread has 2 jobs `arc_reclaim_thread()` calls `arc_adjust()` after calling `arc_kmem_reap_now()`; `arc_adjust()` signals `arc_get_data_buf()` to indicate that we may no longer be `arc_is_overflowing()`. The problem is, `arc_kmem_reap_now()` can take several seconds to complete, has no impact on `arc_is_overflowing()`, but due to how the code is structured, can impact how long the ARC will remain in the `arc_is_overflowing()` state. The fix is to use seperate threads to: 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()`. illumos/illumos-gate@de753e34f9c399037936e8bc547d823bba9d4b0d Reviewed by: Matt Ahrens Reviewed by: Serapheim Dimitropoulos Reviewed by: Pavel Zakharov Reviewed by: Dan Kimmel Reviewed by: Paul Dagnelie Reviewed by: Dan McDonald Reviewed by: Tim Kordas Approved by: Garrett D'Amore Author: Brad Lewis END