w.varint(uint64(pageSize))
	w.varint(uint64(minHeapAlign))
	w.varint(uint64(fixedStack))

	// Finish writing the batch.
	w.flush().end()

	// Start tracing.
	trace := traceAcquire()
	if !trace.ok() {
		throw("traceSnapshotMemory: tracing is not enabled")
	}

	// Write out all the heap spans and heap objects.
	for _, s := range mheap_.allspans {
		if s.state.get() == mSpanDead {

	// but we need to make sure the tracer can only observe the
	// start and end states to maintain a coherent model and avoid
	// emitting an event for every single transition.
	trace := traceAcquire()

	if locked {
		// Detach the goroutine from the thread; we'll attach to the goroutine we're
		// switching to before returning.
		gp.lockedm.set(nil)
	}

	if exit {

		return
	}

	// Disable preemption so the GC can't start while we're
	// sweeping, so we can read h.sweepArenas, and so
	// traceGCSweepStart/Done pair on the P.
	mp := acquirem()

	trace := traceAcquire()
	if trace.ok() {
		trace.GCSweepStart()
		traceRelease(trace)
	}

	arenas := h.sweepArenas
	locked := false
	for npage > 0 {
		// Pull from accumulated credit first.

	semacquire(&worldsema)

	// For stats, check if this GC was forced by the user.
	// Update it under gcsema to avoid gctrace getting wrong values.
	work.userForced = trigger.kind == gcTriggerCycle

	trace := traceAcquire()
	if trace.ok() {
		trace.GCStart()
		traceRelease(trace)
	}

	// Check that all Ps have finished deferred mcache flushes.
	for _, p := range allp {

			// Init functions are executed sequentially in a single goroutine.
			inittrace.bytes += uint64(fullSize)
		}

		if traceAllocFreeEnabled() {
			trace := traceAcquire()
			if trace.ok() {
				trace.HeapObjectAlloc(uintptr(x), typ)
				traceRelease(trace)
			}
		}
	}

	if assistG != nil {
		// Account for internal fragmentation in the assist