Is it possible to turn off threading?

[jeff-davis]

When I do: strace -p $PID -e fork,vfork,clone, I get:

strace: Process 671482 attached
vfork()                                 = 671487
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=671487, si_uid=1000, si_status=0, si_utime=0, si_stime=0} ---
vfork()                                 = 671488
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=671488, si_uid=1000, si_status=0, si_utime=0, si_stime=0} ---
vfork()                                 = 671489
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=671489, si_uid=1000, si_status=0, si_utime=0, si_stime=0} ---
--- SIGALRM {si_signo=SIGALRM, si_code=SI_KERNEL} ---

Is it possible to turn off threading in the runtime? Is that desirable or do we want threading on?