npages := ^uintptr(0)
	var noMoreWork bool
	for {
		s := mheap_.nextSpanForSweep()
		if s == nil {
			noMoreWork = sweep.active.markDrained()
			break
		}
		if state := s.state.get(); state != mSpanInUse {
			// This can happen if direct sweeping already
			// swept this span, but in that case the sweep
			// generation should always be up-to-date.
			if !(s.sweepgen == sl.sweepGen || s.sweepgen == sl.sweepGen+3) {

	}

	return x, span
}

// isUnusedUserArenaChunk indicates that the arena chunk has been set to fault
// and doesn't contain any scannable memory anymore. However, it might still be
// mSpanInUse as it sits on the quarantine list, since it needs to be swept.
//
// This is not safe to execute unless the caller has ownership of the mspan or
// the world is stopped (preemption is prevented while the relevant state changes).

		case "/memory/classes/metadata/mspan/free:bytes":
			checkUint64(t, name, samples[i].Value.Uint64(), mstats.MSpanSys-mstats.MSpanInuse)
		case "/memory/classes/metadata/mspan/inuse:bytes":
			checkUint64(t, name, samples[i].Value.Uint64(), mstats.MSpanInuse)
		case "/memory/classes/metadata/other:bytes":
			checkUint64(t, name, samples[i].Value.Uint64(), mstats.GCSys)
		case "/memory/classes/os-stacks:bytes":

func CountPagesInUse() (pagesInUse, counted uintptr) {
	stw := stopTheWorld(stwForTestCountPagesInUse)

	pagesInUse = mheap_.pagesInUse.Load()

	for _, s := range mheap_.allspans {
		if s.state.get() == mSpanInUse {
			counted += s.npages
		}
	}

	startTheWorld(stw)

	return
}

func Fastrand() uint32          { return uint32(rand()) }
func Fastrand64() uint64        { return rand() }

	fmt.Fprintf(w, "# HeapReleased = %d\n", s.HeapReleased)
	fmt.Fprintf(w, "# HeapObjects = %d\n", s.HeapObjects)

	fmt.Fprintf(w, "# Stack = %d / %d\n", s.StackInuse, s.StackSys)
	fmt.Fprintf(w, "# MSpan = %d / %d\n", s.MSpanInuse, s.MSpanSys)
	fmt.Fprintf(w, "# MCache = %d / %d\n", s.MCacheInuse, s.MCacheSys)
	fmt.Fprintf(w, "# BuckHashSys = %d\n", s.BuckHashSys)
	fmt.Fprintf(w, "# GCSys = %d\n", s.GCSys)