lowest_to_date    691 kernel/exit.c  	static int lowest_to_date = THREAD_SIZE;
lowest_to_date    696 kernel/exit.c  	if (free >= lowest_to_date)
lowest_to_date    700 kernel/exit.c  	if (free < lowest_to_date) {
lowest_to_date    703 kernel/exit.c  		lowest_to_date = free;