Posted at LWN.net is a report on a visit to the OpenNMS facilities. "If you've built your own kernel, as I had, you'll probably have to
rebuild it to increase the maximum allowed tasks. The default when
you build a kernel is 256, and OpenNMS uses more than 400 threads.
Edit your include/linux/tasks.h file and rebuild. Users who run
with the kernel that came with a popular distribution probably
won't have a problem, as the distros are compiled with the value
March 13, 2001