current kernels hang on i386 and amd64

[Kurt Schreiner <ks%ub.uni-mainz.de@localhost>]

Hi,

kernels compiled from -current source cvs updated May 22 20:18 MEST
hang under heavy load. The i386 machine is a P4 2.8GHz, HT enabled
w/ 2GB Ram and hangs after working some minutes on "build.sh -j8 ...
release". "Hang" means no answer to ping, no drop to ddb, no answer
to (PS/2-)keyboard only reset or power button helps.
The amd64 machine is a Q6600 w/ 8GB Ram and hangs after working
some minutes on "build.sh -j31 ... release". "Hang" is the same
as above. I've seen no problems w/ lighter loads (-j2 resp. -j12).
Last working kernels on both machines are from May 16...

Anyone any idea what's going on?

Kurt