work.tEnd = now
	atomic.Store64(&memstats.last_gc_unix, uint64(unixNow)) // must be Unix time to make sense to user
	atomic.Store64(&memstats.last_gc_nanotime, uint64(now)) // monotonic time for us
	memstats.pause_ns[memstats.numgc%uint32(len(memstats.pause_ns))] = uint64(work.pauseNS)
	memstats.pause_end[memstats.numgc%uint32(len(memstats.pause_end))] = uint64(unixNow)
	memstats.pause_total_ns += uint64(work.pauseNS)

	h.cachealloc.init(unsafe.Sizeof(mcache{}), nil, nil, &memstats.mcache_sys)
	h.specialfinalizeralloc.init(unsafe.Sizeof(specialfinalizer{}), nil, nil, &memstats.other_sys)
	h.specialprofilealloc.init(unsafe.Sizeof(specialprofile{}), nil, nil, &memstats.other_sys)
	h.specialReachableAlloc.init(unsafe.Sizeof(specialReachable{}), nil, nil, &memstats.other_sys)

		if l2[ri.l2()] != nil {
			throw("arena already initialized")
		}
		var r *heapArena
		r = (*heapArena)(h.heapArenaAlloc.alloc(unsafe.Sizeof(*r), goarch.PtrSize, &memstats.gcMiscSys))
		if r == nil {
			r = (*heapArena)(persistentalloc(unsafe.Sizeof(*r), goarch.PtrSize, &memstats.gcMiscSys))
			if r == nil {
				throw("out of memory allocating heap arena metadata")
			}
		}

		// Register the arena in allArenas if requested.

}

// memoryUsage converts working set into a resource quantity.
func memoryUsage(memStats *statsapi.MemoryStats) *resource.Quantity {
	if memStats == nil || memStats.WorkingSetBytes == nil {
		return &resource.Quantity{Format: resource.BinarySI}
	}
	usage := int64(*memStats.WorkingSetBytes)
	return resource.NewQuantity(usage, resource.BinarySI)
}

				nbytes := int64(npages * pageSize)
				gcController.heapReleased.add(nbytes)
				gcController.heapFree.add(-nbytes)

				stats := memstats.heapStats.acquire()
				atomic.Xaddint64(&stats.committed, -nbytes)
				atomic.Xaddint64(&stats.released, nbytes)
				memstats.heapStats.release()
			}

			// Relock the heap, because now we need to make these pages

	lastHeapGoal uint64

	// heapLive is the number of bytes considered live by the GC.
	// That is: retained by the most recent GC plus allocated
	// since then. heapLive ≤ memstats.totalAlloc-memstats.totalFree, since
	// heapAlloc includes unmarked objects that have not yet been swept (and
	// hence goes up as we allocate and down as we sweep) while heapLive

	case memProfile:
		size += unsafe.Sizeof(memRecord{})
	case blockProfile, mutexProfile:
		size += unsafe.Sizeof(blockRecord{})
	}

	b := (*bucket)(persistentalloc(size, 0, &memstats.buckhash_sys))
	b.typ = typ
	b.nstk = uintptr(nstk)
	return b
}

// stk returns the slice in b holding the stack. The caller can asssume that the
// backing array is immutable.

// The resulting bitvector will have no more than size/goarch.PtrSize bits.
func progToPointerMask(prog *byte, size uintptr) bitvector {
	n := (size/goarch.PtrSize + 7) / 8
	x := (*[1 << 30]byte)(persistentalloc(n+1, 1, &memstats.buckhash_sys))[:n+1]
	x[len(x)-1] = 0xa1 // overflow check sentinel
	n = runGCProg(prog, &x[0])
	if x[len(x)-1] != 0xa1 {
		throw("progToPointerMask: overflow")
	}
	return bitvector{int32(n), &x[0]}
}