Hello ,
I have
{MM8}root@Node2:/data/tmp# uname -a
Linux Node2 2.6.10-telco-1.46-mckinley-smp #1 SMP Fri May 30 18:29:43 UTC 2008 ia64 GNU/Linux
# ls /lib/libpthread*
libpthread-0.10.so libpthread.so.0

I have 2-processes (lets say p1 and p2)
p1 has about 49 threads
p2 has about 17 threads

If p1 hangs , then p2 sends a signal SIGUSR2 using pthread_kill(threadid_p1, sigusr2)

While doing so , pthread_kill dumped core, stack trace is as below
==========================
Program terminated with signal 11, Segmentation fault.
#0 0x20000000000ffef0 in pthread_kill () from /lib/tls/libpthread.so.0
(gdb) bt
#0 0x20000000000ffef0 in pthread_kill () from /lib/tls/libpthread.so.0
==============================




ls -lrt /lib/tls/libpthread.so.0
lrwxrwxrwx 1 root root 18 Aug 29 11:18 /lib/tls/libpthread.so.0 -> libpthread-0.60.so


Advance thanks for the help

Moved to programming, your duplicate in Software will soon be closed.

I'm guessing that if p1 hangs then it's on a blocking function call. Is that the case? I can't think of any other reason a thread would hang. If it is a blocking function call, the signal should release the block but something might be incomplete. This can happen if you expect a pointer to be assigned during the call and that pointer hadn't contained a valid value before the call.

Does the signal handler call pthread_cancel on p1? If so, I've always had problems using that on threads I didn't specifically set up to be canceled well.
ta0kira