[src/trunk]: src/sys/arch/x68k/include Increase VM_KERNEL_PT_PAGES from 2 to ...

[tsutsui <tsutsui%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9e7a78c0d2b4
branches:  trunk
changeset: 326296:9e7a78c0d2b4
user:      tsutsui <tsutsui%NetBSD.org@localhost>
date:      Sat Jan 25 00:07:48 2014 +0000

description:
Increase VM_KERNEL_PT_PAGES from 2 to 4 for x68k.

X68030 with 8MB or 12MB RAM (which is default for most X68030s)
now gets "pmap_enter_ptpage: can't get KPT page" panic again
with VM_KERNEL_PT_PAGES=2 while it works with >=14MB.
3 is enough to boot for now, but I also add a spare.

I guess this is because the post netbsd-6 vmem(9) bootstrap
changes require more kernel memory before MD pmap_init().

Note1:  netbsd-6 (which also pulls physmem detection changes
        that affect nptpages) doesn't have this problem.
Note2:  other hp300 pmap based m68k ports might have the same issue,
        but at least 12MB luna68k works with VM_KERNEL_PT_PAGES=2
        so I think it depends on kernel size and/or iomapsize.

diffstat:

 sys/arch/x68k/include/vmparam.h |  4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diffs (18 lines):

diff -r dc52cf4fa090 -r 9e7a78c0d2b4 sys/arch/x68k/include/vmparam.h
--- a/sys/arch/x68k/include/vmparam.h   Sat Jan 25 00:03:14 2014 +0000
+++ b/sys/arch/x68k/include/vmparam.h   Sat Jan 25 00:07:48 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vmparam.h,v 1.35 2012/01/21 20:19:55 tsutsui Exp $     */
+/*     $NetBSD: vmparam.h,v 1.36 2014/01/25 00:07:48 tsutsui Exp $     */
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -107,7 +107,7 @@
 #define VM_PHYS_SIZE           (USRIOSIZE*PAGE_SIZE)
 
 /* # of kernel PT pages (initial only, can grow dynamically) */
-#define VM_KERNEL_PT_PAGES     ((vsize_t)2)            /* XXX: SYSPTSIZE */
+#define VM_KERNEL_PT_PAGES     ((vsize_t)4)            /* XXX: SYSPTSIZE */
 
 /*
  * Constants which control the way the VM system deals with memory segments.