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Date: Sat, 25 Apr 2020 21:18:10 +0300
From: Slawa Olhovchenkov <slw@zxy.spb.ru>
To: freebsd-current@freebsd.org
Subject: Kernel free memory control / pressure
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I am looked to code control kernel free memory /p ressure and see some
strange points:

- vm.v_free_target is RW but do nothing. You can set it to any value
  and this is don't have any effect.
- vmd_free_target (as vm.domain.N.stats.free_target) is RD and don't
  have any sysctl to tune

Same for v_free_min, v_free_reserved, v_pageout_free_min.

As I see this behavior for 12 and current branches, after-NUMA
kernels.

Is this expected behavior?

PS:

(kgdb) p vm_dom[0].vmd_page_count
$2 = 33454844
(kgdb) p vm_dom[1].vmd_page_count
$3 = 31872620

What source of  vm_dom[0].vmd_page_count > vm_dom[1].vmd_page_count?