[hpoj-devel] Re: SMP Problems with hpoj-0.6

[<pa...@rc...>]

> First of all it's not a problem of version 0.6, it's more general, since
> 0.5 make the same problems. It's really a problem of the SMP kernel:
> (Seems I've never tested 0.5 with a SMP kernel.)
> 
> If I boot a non-SMP kernel and load the modules I build on this kernel,
> it works (I've at least printed one page with ptal-connect).
> If I boot the SMP kernel and load the SMP kernel modules it crashes at
> "hpo devid".
Hi, Alexander.  I feel a little better knowing that I didn't break it in
my changes for 0.6.  :-)

> If I try to load the modules build with the non-SMP kernel into the
> running SMP kernel it gives unresolved kernel symbols (and also
> vice-versa), although the module and kernel source where the same!
Switching between SMP and non-SMP kernels may change version information
attached to kernel symbols.  This would cause unresolved kernel symbol
errors as if you had switched kernel versions.

> Don't you have any kernel expert at your hand, that may help us?
Unfortunately, the people who originally developed this code are no
longer maintaining it.  There is one other person who indicated an
interest in resolving another kernel problem.  I forwarded your and my
messages to the hpoj-devel mailing list in hopes that somebody might be
able to assist.  If you haven't already, please subscribe to this list
and use that for further communications about this issue, so that others
can follow along.

> But now, how to track this error. Before chrashing there are a lot of
> messages displayed on the screen (virtual consule 1), but these are not
> in the log file after rebooting, and scrolling up the screen doesn't
> work any more, when the kernel crashed. Redirecting to file also does
> not work. Any idea?
Redirecting to a file wouldn't work because the messages are sent directly
to the console by the kernel, rather than through standard output or
standard error of any particular process.

Is there any way you can run an SMP kernel but somehow force your computer
to only activate one CPU, either by a BIOS setup option, dip switch/jumper,
or physically removing one CPU (but be careful!)?  If you can duplicate
this problem with an SMP kernel on a uniprocessor system then I might be
able to scrounge up an extra PC and set it up to work on this problem if
nobody else can.

David