// the ranges of described in alloc and scavenge.
func makePallocData(alloc, scavenged []BitRange) *PallocData {
	b := new(PallocData)
	for _, v := range alloc {
		if v.N == 0 {
			// Skip N==0. It's harmless and allocRange doesn't
			// handle this case.
			continue
		}
		b.AllocRange(v.I, v.N)
	}
	for _, v := range scavenged {
		if v.N == 0 {
			// See the previous loop.
			continue
		}

		panic("must populate all stubs")
	}

	// Install hooks.
	s.scavenger.sleepStub = s.Sleep
	s.scavenger.scavenge = s.Scavenge
	s.scavenger.shouldStop = s.ShouldStop
	s.scavenger.gomaxprocs = s.GoMaxProcs

	// Start up scavenger goroutine, and wait for it to be ready.
	stop := make(chan struct{})
	s.stop = stop
	done := make(chan struct{})
	s.done = done
	go func() {

	},
	{
		Name: "/cpu/classes/scavenge/total:cpu-seconds",
		Description: "Estimated total CPU time spent performing tasks that return " +
			"unused memory to the underlying platform. " +
			"This metric is an overestimate, and not directly comparable to " +
			"system CPU time measurements. Compare only with other /cpu/classes " +
			"metrics. Sum of all metrics in /cpu/classes/scavenge.",
		Kind:       KindFloat64,

	condemned = nil

	// Clear the condemned memory.
	runtime.GC()

	// At this point, the background scavenger is likely running
	// and could pick up the work, so the next line of code doesn't
	// end up doing anything. That's fine. What's important is that
	// this test fails somewhat regularly if the runtime doesn't
	// scavenge on heap growth, and doesn't fail at all otherwise.

	/cpu/classes/scavenge/assist:cpu-seconds
		Estimated total CPU time spent returning unused memory to the
		underlying platform in response eagerly in response to memory
		pressure. This metric is an overestimate, and not directly
		comparable to system CPU time measurements. Compare only with
		other /cpu/classes metrics.

	/cpu/classes/scavenge/background:cpu-seconds

		case "/cpu/classes/idle:cpu-seconds":
			cpu.idle = samples[i].Value.Float64()
		case "/cpu/classes/scavenge/assist:cpu-seconds":
			cpu.scavengeAssist = samples[i].Value.Float64()
		case "/cpu/classes/scavenge/background:cpu-seconds":
			cpu.scavengeBg = samples[i].Value.Float64()
		case "/cpu/classes/scavenge/total:cpu-seconds":
			cpu.scavengeTotal = samples[i].Value.Float64()
		case "/cpu/classes/total:cpu-seconds":

	inUse addrRanges

	// scav stores the scavenger state.
	scav struct {
		// index is an efficient index of chunks that have pages available to
		// scavenge.
		index scavengeIndex

		// releasedBg is the amount of memory released in the background this
		// scavenge cycle.
		releasedBg atomic.Uintptr

		// releasedEager is the amount of memory released eagerly this scavenge
		// cycle.
		releasedEager atomic.Uintptr

const lockRankLeafRank lockRank = 1000

// lockNames gives the names associated with each of the above ranks.
var lockNames = []string{
	lockRankSysmon:          "sysmon",
	lockRankScavenge:        "scavenge",
	lockRankForcegc:         "forcegc",
	lockRankDefer:           "defer",
	lockRankSweepWaiters:    "sweepWaiters",
	lockRankAssistQueue:     "assistQueue",
	lockRankSweep:           "sweep",

			},
		},
		"/cpu/classes/scavenge/assist:cpu-seconds": {
			deps: makeStatDepSet(cpuStatsDep),
			compute: func(in *statAggregate, out *metricValue) {
				out.kind = metricKindFloat64
				out.scalar = float64bits(nsToSec(in.cpuStats.ScavengeAssistTime))
			},
		},
		"/cpu/classes/scavenge/background:cpu-seconds": {
			deps: makeStatDepSet(cpuStatsDep),

	scavAssistCpu := scavenge.assistTime.Load()
	scavBgCpu := scavenge.backgroundTime.Load()

	// Update cumulative GC CPU stats.
	s.GCAssistTime += markAssistCpu
	s.GCDedicatedTime += markDedicatedCpu + markFractionalCpu
	s.GCIdleTime += markIdleCpu
	s.GCTotalTime += markAssistCpu + markDedicatedCpu + markFractionalCpu + markIdleCpu

	// Update cumulative scavenge CPU stats.