I'm able to generate a lot of hangs with 2.5.41-mm1.
This is on a 8-way PIII-700, 16 GB ram (PAE enabled)

The first one, I got by running ltp for a while, then the attached test
for a bit, then, at the suggestion of Bill Irwin to increase the amount
of ram I could be using for huge pages:
echo 768 > /proc/sys/vm/nr_hugepages

Doing that (and the corresponding echo 1610612736 >
/proc/sys/kernel/shmmax) after a cold boot gave me no problems though.

I also got it to hang after runnging the attached test with -s
1610612736 and then running another one with no options.

There was no output on the serial console when it hung, and it was
unresponsive to ping, vc switch, and sysrq.

The attached test is an ltp shmem test modified by Bill Irwin to support
the shm huge pages in 2.5.41-mm1.  Compile it with --static.

Thanks,
Paul Larson