Simple, but more useful: mlockall

• Prevents process from being swapped out to disk

• Useful for sensitive data, or time-critical operations

• Must be root, otherwise a user could easily DOS the system

• Flags come from /usr/include/sys/mman.h

syscall(&SYS_mlockall, &MCL_CURRENT|&MCL_FUTURE) == 0 or die "mlockall: $!\n";