Function statclock

freebsd/kern/kern_clock.c:639–721

* Statistics clock. Updates rusage information and calls the scheduler * to adjust priorities of the active thread. * * This should be called by all active processors. */

 * This should be called by all active processors.
 */
void
statclock(int cnt, int usermode)
{
	struct rusage *ru;
	struct vmspace *vm;
	struct thread *td;
	struct proc *p;
	long rss;
	long *cp_time;
	uint64_t runtime, new_switchtime;

	td = curthread;
	p = td->td_proc;

	cp_time = (long *)PCPU_PTR(cp_time);
	if (usermode) {
		/*
		 * Charge the time as appropriate.
		 */
		td->td_uticks += cnt;
		if (p->p_nice > NZERO)
			cp_time[CP_NICE] += cnt;
		else
			cp_time[CP_USER] += cnt;
	} else {
		/*
		 * Came from kernel mode, so we were:
		 * - handling an interrupt,
		 * - doing syscall or trap work on behalf of the current
		 *   user process, or
		 * - spinning in the idle loop.
		 * Whichever it is, charge the time as appropriate.
		 * Note that we charge interrupts to the current process,
		 * regardless of whether they are ``for'' that process,
		 * so that we know how much of its real time was spent
		 * in ``non-process'' (i.e., interrupt) work.
		 */
		if ((td->td_pflags & TDP_ITHREAD) ||
		    td->td_intr_nesting_level >= 2) {
			td->td_iticks += cnt;
			cp_time[CP_INTR] += cnt;
		} else {
			td->td_pticks += cnt;
			td->td_sticks += cnt;
			if (!TD_IS_IDLETHREAD(td))
				cp_time[CP_SYS] += cnt;
			else
				cp_time[CP_IDLE] += cnt;
		}
	}

	/* Update resource usage integrals and maximums. */
	MPASS(p->p_vmspace != NULL);
	vm = p->p_vmspace;
	ru = &td->td_ru;
	ru->ru_ixrss += pgtok(vm->vm_tsize) * cnt;
	ru->ru_idrss += pgtok(vm->vm_dsize) * cnt;
	ru->ru_isrss += pgtok(vm->vm_ssize) * cnt;