830ab6bb3c
1 microsecond into the future, the thread could enter an untimed sleep. - Change the signature of _lwp_park() to accept an lwpid_t and second hint pointer, but do so in a way that remains compatible with older pthread libraries. This can be used to wake another thread before the calling thread goes asleep, saving at least one syscall + involuntary context switch. This turns out to be a fairly large win on the condvar benchmarks that I have tried. - Mark some more syscalls MP safe.