Mol Freeze (cont.)

[mol-devel@lists.maconlinux.org]

On Fri, May 24, 2002 at 02:58:15PM +0200, Francois Taiani wrote:
> Some weeks ago Samuel suggested a bug fix related to Virtual Memory 
> management that greatly improved mol's stability on my machine. Though, 
> I still experiment freezes now and then, that don't appear when I use 
> MacOS outside mol.
> 
> I was wondering how I could get more info on the context of these 
> freezes. I can attach a gdb process to the mol session, but the info I 
> can get from there seems to be quite thin 

Well, it really isn't MOL that is stuck but MacOS. Thus gdb
won't tell you anything useful.

> I've seen a debugger comes along 
> with mol, but it looks quite obsure to me.

The MOL debugger is the best tool (and more or less the only one) 
for tracking down a freeze. This is not a trivial process though, 
and it is not certain enough state information is available
to reconstruct what happened...

> I'd be very grateful for any hint on how I could obtain more insight in 
> my problem than just say "Mol has just frozen again !".

A few things to check:

- The kernel version. Older 2.4 kernels have various MM
problems. MOL exercises the MM layer quite a bit...

- Make sure you are loading the "MacOS ROM" file 
from the boot volume. Usage of older MacOS ROM files sometimes
work but the mismatch will usually cause random freezes.

- Try turning off AltiVec if you have a G4. There is,
I think, an assumption that certain MOL c-code won't affect
the altivec registers. If glibc/gcc ever gets altivec optimized,
it might be necessary to save the AltiVec registers more
often.

- A not-too-old glibc version. The pthread support used to
be quite buggy.

What hardware do you have btw (in particular, how much memory)?

Cheers,

/Samuel