linuxthreads uses the ldt to identify the threads in a process. This 
results in a modify_ldt call, which causes a 64kB vmalloc call, for 
every process that is linked against libpthread. vmalloc space is often 
tight, which limits the number of processes that can run concurrently. I 
remember one report of failures with 80 users on a multiuser kde x-server.
The attached patch changes the ldt allocation to try to use kmalloc if 
possible, and to limit the initial allocation size to 2 kB. 
Additionally, the patch adds proper failure returns. The curent code 
just prinkt's the error and continues the fork() syscall [and silently 
drops the ldt].

2.6 contains a similar patch, and it was (is?) in several distro and ac 
kernels.

Marcelo, could you add it to your tree?

--
    Manfred