Books are static, the software is subject to change. The book was published in December 2004 and the sysctl was added just that year.
Code:
CVSROOT: /cvs
Module name: src
Changes by: tedu@cvs.openbsd.org 2004/04/19 16:52:33
Modified files:
sys/kern : kern_sysctl.c uipc_mbuf.c
sys/sys : sysctl.h
sys/uvm : uvm_extern.h uvm_init.c uvm_km.c uvm_km.h
Log message:
introduce a new km_page allocator that gets pages from kernel_map using
an interrupt safe thread.
use this as the new backend for mbpool and mclpool, eliminating the mb_map.
introduce a sysctl kern.maxclusters which controls the limit of clusters
allocated.
testing by many people, works everywhere but m68k. ok deraadt@
this essentially deprecates the NMBCLUSTERS option, don't use it.
this should reduce pressure on the kmem_map and the uvm reserve of static
map entries.