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Re: [vox-tech] crashes -- kernel problems?
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Re: [vox-tech] crashes -- kernel problems?

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On Sun, May 04, 2003 at 03:09:14PM -0700, Charles McLaughlin wrote:
> I'm running debian unstable on my laptop.  I've recompiled my kernel
> (2.4.20) several times in order to get some of hardware to work.
> The system has completely froze several times.  When this happens, I
> can't move the mouse, type, etc.  It seems to happen when I'm doing
> network related stuff, like using Mozilla or gftp. =20

- Have you figured out a way to reproduce the lock up?
  (as in given 15 minutes you make the machine lock for sure)

- Have you ever had the machine lock while you are out on the text console?

- Are you *actively* using the machine when it locks?
  (or does it happen when you do something and step away for 5 minutes
   then come back to find it frozen).

  It is important to observe and record what things were happening prior
to each crash then try to isolate what steps lead to the crash... this
way you can be sure when you have fixed the problem.

  If it is a network problem you should be able to repeat on the
console... if not

On Sun, May 04, 2003 at 03:41:29PM -0700, Peter Jay Salzman wrote:
> first thing to do is to learn about the magic sysrq key so you can sync
> and umount your drives gracefully, in case this really is a kernel
> related issue.  make sure this option is compiled into your kernel.

  Good idea.

On Tue, May 06, 2003 at 01:07:05PM -0700, Charles McLaughlin wrote:
> I recompiled my kernel with support for the magic sysrq key.  I'm having
> some problems using it though.  In order for me to press the sysreq key, I
> have to hold down the function (fn) key on my laptop.  The function key
> turns part of my laptop keyboard into a number pad, so when I attempt to
> press alt+sysreq+U to unmount, it translates to alt+syreq+4.
> Is there a way to map the sysreq key to another key?

from the Documentation: /usr/src/linux/Documentation/sysrq.txt
  *  I hit SysRq, but nothing seems to happen, what's wrong?
  There are some keyboards that send different scancodes for SysRq than the
  pre-defined 0x54. So if SysRq doesn't work out of the box for a certain
  keyboard, run 'showkey -s' to find out the proper scancode sequence.
  Then use 'setkeycodes <sequence> 84' to define this sequence to the
  usual SysRq code (84 is decimal for 0x54). It's probably best to put
  this command in a boot script. Oh, and by the way, you exit 'showkey'
  by not typing anything for ten seconds.

  Pick another scan code that doesn't the laptop FN to pressed to act as
sysrq.  Try testing alt-sysrq-h on the console to see if you have it=20

> > second thing to do is to ping or try to ssh into the machine to see if
> > the kernel is really gone or the input system is just hosed (which
> > happens).  at least then you can perform an ordinary shut down.
> I can't ping it or ssh into it when it crashes.

  That strongly hints that there is a kernel bug or hardware problem
locking the machine.

  Once sysrq is working: S, U, B with a little delay between characters=20
is what you will want to use to reboot after a crash.  If you hit
the 'b' and it doesn't reboot, it hints more hardware (or very bad
kernel bug).

On Tue, May 06, 2003 at 01:28:11PM -0700, Peter Jay Salzman wrote:
> begin Charles McLaughlin <cmclaughlin@ucdavis.edu>=20
> > > jooc, are you running 2.4.20-pre-something or the officially released
> > > 2.4.20?
> >=20
> > I'm using the official 2.4.20.
> one more question -- what distro are you using?

  He said Debian/unstable a while back (his quote was even at the bottom
of your email where you asked this, way way down there :) ...=20

On Sun, May 04, 2003 at 03:34:38PM -0700, Charles McLaughlin wrote:
> Maybe I should have mentioned that I noticed something I find
> suspicous.  I ran dmesg and found the following:
> Local APIC disabled by BIOS -- reenabling.
> Could not enable APIC!
> <snip>
> Local APIC not detected. Using dummy APIC emulation.
> Also, my laptop doesn't powerdown when I shut it down.  Instead, when I
> attept to shutdown it just sits at a terminal screen and says 'power
> down'.  I recently updated the bios, but that didn't change anything.
> I wonder if this could be related to the crashes....?

On Sun, May 04, 2003 at 03:45:18PM -0700, Peter Jay Salzman wrote:
> this is prolly unrelated.  there's a kernel config option that talks
> about using real-mode calls for a shut down.  enable that option and
> you'll get a poweroff as well as a kernel shutdown.

  The APIC issue _could_ be related to the crashes, the power down is=20
simply a mis-configuration of the kernel configuration as Pete says.


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