> That leaves unanswered the underlying question: why do you need to do
> this at all? Isn't the ZFS ARC supposed to release memory when the
> system is under pressure? Is that mechanism not working well in some
> cases ... ?
" ... Even if the ZFS ARC subsequently frees memory, the kernel cage does
not shrink. It cannot shrink, because pages from the ZFS ARC were
interspersed with other kernel pages, so the free space in the
physical address range of the cage is fragmented when the ZFS pages
are released. The remaining kernel pages cannot be moved to compress
the cage, as kernel memory inside the cage is not relocatable. ..."
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