Date: Thu, 22 Jul 1999 15:20:22 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: "Christopher W. Banek" <unixboy@imsa.edu> Cc: freebsd-smp@FreeBSD.ORG Subject: Re: Page Fault Problems with SMP kernel in 3.2-RELEASE Message-ID: <199907222220.PAA88210@apollo.backplane.com> References: <Pine.SOL.4.02.9907221627580.22357-100000@pepsi>
next in thread | previous in thread | raw e-mail | index | archive | help
:Hi. I am a a bit new to FreeBSD, came over from linux, but here is what
:is happening. I installed 3.2-RELEASE and everything went fine. I
:compilied an SMP kernel and now it page faults when ever I am doing
:something system intensive. It happens during configure scripts, but not
:when I do a make. But if I do a make -j2, it crashes quickly.
:
:Oh yeah, I have a GA-686LX2 with Dual PII/333 and 128MB of Ram.
There's a good chance the problem has been fixed in FreeBSD-STABLE
(i.e. changes made since the 3.2 release), but it's hard to tell
from the information you provided.
There are two ways to get additional information:
* Try to get the kernel to generate a kernel core dump
This involves having a swap area that is at least as large as
main memory.
Setting the dumpdev in /etc/rc.conf correctly. If you have IDE
disks it might be something like I show below. Note that you
have to be careful to specify the correct partition name. Swap
partitions almost always end with 'b'.
dumpdev="/dev/wd0b"
Ensuring that /var/crash exists and has enough free space to hold
the dump (at least as much space as you have main memory, plus a
couple of megabytes more). You can make /var/crash a softlink to
some other partition if /var doesn't have enough space. For example
you can create a /usr/crash and then remove /var/crash and create
a softlink 'ln -s /usr/crash /var/crash'.
Once these changes are made and you reboot, the next time the machine
crashes it should be able to generate a kernel core. You can then
gdb the core like this:
cd /var/crash
ls -la
gdb -k kernel.0 vmcore.0 (or whatever
the names wind up being)
back (to get a backtrace)
* Recompile the kernel with the DDB option turned on. Now when the
kernel crashes it will drop into a DDB> prompt and you should be
able to do a 'trace' to get a call stack backtrace from which we
may be able to get more information. (Then type 'panic' and hit
return a couple of times to panic the system).
Recompiling the kernel for someone who has never done it before
can take a bit of work.
If the problem has already been solved you will have to learn how to
download the latest source dist in order to recompile a new kernel.
Take a look at the FreeBSD documentation, especially the handbook.
See http://www.freebsd.org/
-Matt
Matthew Dillon
<dillon@backplane.com>
:Here is the exact error message.
:
:Fatal trap 12: page fault while in kernel mode
:mp_lock = 01000002; cpuid=1; lapic.id=01000000
:fault virtual address = 0x2b
:fault code = supervisor read, page not present
:instruction pointer = 0x8:0xc01cb3ab
:stack pointer = 0x10:0xc4a41e40
:frame pointer = 0x10:0xc4a41e4c
:code segment = base 0x0, limit 0xfffff, type ox1b
: = DPL 0, pres1, def32, gran 1
:processor eflags - interrupt enabled, resume,IOPL = 0
:current process = 2800 (sh)
:inturrupt mask = net tty bio cam <- SMP: XXX
:trap number = 12
:panic: page fault
:mp_lock = 01000002; cpuid = 1; lapic.id = 01000000
:boot() called on cpu#1
:
:
:Thanks for any help you guys can provide.
:Christopher Banek
:
:
:
:
:To Unsubscribe: send mail to majordomo@FreeBSD.org
:with "unsubscribe freebsd-smp" in the body of the message
:
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-smp" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199907222220.PAA88210>