I would like to know if the Apache I am running on RedHat has been compiled with the option lpthread?
On RedHat Linux, run the following command:
# ldd /usr/sbin/httpd
and see in the output if you get the following (or similar by version):
libpthread.so.0 => /lib/libpthread.so.0 (0x00284000)
If you see this then httpd has been compiled with lpthread option.