Also, output of ./configure (without any special flags) of lwp-2.1 gives the
following output
related to threading:


checking for pthread_create in -lpthread... yes
checking for sem_init in -lposix4... no
checking ucontext.h usability... yes
checking ucontext.h presence... yes
checking for ucontext.h... yes
checking for register_t... yes
checking for stack_t... yes
checking for sigaltstack... yes
checking for stdlib.h... (cached) yes
checking for unistd.h... (cached) yes
checking for getpagesize... yes
checking for working mmap... yes

blah, blah, blah

that is, seems to be configuring to link with flag -lpthread, from looking
at
the Makefile.

Regards, Sean
scaron_at_umich.edu