just to write it down somewhere:

using pd in realtime-mode and Gem used to crash the system on linux (hard freeze)

the problem used to be following:

opening a glx-window when page-locking (with mlockall()) is enabled, makes pd use 100% CPU and you cannot kill it anymore. in combination with the realtime-scheduling this leads to a hard lock of the system: only rebooting helps

but help is on the way: with kernel-2.6.10 it is now possible (again) to run pd in realtime mode and at the same time use Gem without having a hard system freeze.

mfg.asd.r IOhannes

PS: but be prepared to have some difficulties to get nvidia's drivers working with 2.6.10 ;-)

hint: you have to replace "pci_find_class" with "pci_get_class" in the nv.c-file

hint: and only 66.29 (which is the current version at this time) works for me