Re: page fault panic in vm system

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:On Tue, Jul 05, 2011 at 08:47:46AM -1000, Peter Avalos wrote:
:> I got a panic 2 nights in a row (both at around 2:55am which is weird).
:>=20
:
:I got another panic last night with mysqld as the current process.  The
:kernel for this one is:
:
:DragonFly ylem.theshell.com 2.11-DEVELOPMENT DragonFly
:v2.11.0.491.g96956-DEVELOPMENT #54: Tue Jul  5 23:12:44 HST 2011
:root@ylem.theshell.com:/usr/obj/usr/src/sys/YLEM  i386
:
:I wasn't able to get a core, but this was on the console.  Not sure if
:much can be gained from this:
:
:Fatal trap 12: page fault while in kernel mode
:cpuid =3D 1; lapic.id =3D 02000000
:fault virtual address   =3D 0x14
:fault code              =3D supervisor read, page not present
:instruction pointer     =3D 0x8:0xc02f2e20

    This is vm_page_rb_tree_RB_LOOKUP() .. the red-black lookup code
    for a vm_page in an object.  Called from vm_page_lookup().

    Currently the global vm_token protects that field.  I didn't see any
    particular race there but the problem could be related to a more
    general reference count problem with VM objects.

					-Matt