vm.defer_swapspace_pageouts と vm.disable_swapspace_pageouts
デフォルトはどちらも0
vm.defer_swapspace_pageouts
vm.defer_swapspace_pageouts causes the system to avoid using swap,
if possible. With the option enabled, the VM system will still
evict clean pages and read them in again from the filesystem when
necessary, but it will only write dirty pages to the swap
partition as a last resort.
可能であればスワップを使用しない？
Linuxのswappiness=0のような挙動になる？
(2017/12/15 FreeBSD 11.1で項目なくなってた)
Log: vm.defer_swapspace_pageouts was removed in r308474.
