// Started running while doing GC things.
					ps[ev.Proc()].gc++
				} else if old.Executing() && !new.Executing() {
					// Stopped running while doing GC things.
					ps[ev.Proc()].gc--
				}
			}
			states[g] = new
		case EventLabel:
			l := ev.Label()
			if flags&UtilBackground != 0 && strings.HasPrefix(l.Label, "GC ") && l.Label != "GC (idle)" {
				// Background mark worker.
				//

func DeferLiveness() {
	var x [10]int
	escape(&x)
	fn := func() {
		if x[0] != 42 {
			panic("FAIL")
		}
	}
	defer fn()

	x[0] = 42
	runtime.GC()
	runtime.GC()
	runtime.GC()
}

//go:noinline
func escape(x any) { sink2 = x; sink2 = nil }

var sink2 any

// Test zombie object detection and reporting.
func GCZombie() {

	ppath := p.ImportPath
	if cfg.BuildBuildmode == "plugin" {
		ppath = pluginPath(a)
	} else if p.Name == "main" && !p.Internal.ForceLibrary {
		ppath = "main"
	}
	return ppath
}

func (gcToolchain) gc(b *Builder, a *Action, archive string, importcfg, embedcfg []byte, symabis string, asmhdr bool, pgoProfile string, gofiles []string) (ofile string, output []byte, err error) {
	p := a.Package
	sh := b.Shell(a)
	objdir := a.Objdir

		to system CPU time measurements. Compare only with other
		/cpu/classes metrics.

	/gc/cycles/automatic:gc-cycles
		Count of completed GC cycles generated by the Go runtime.

	/gc/cycles/forced:gc-cycles
		Count of completed GC cycles forced by the application.

	/gc/cycles/total:gc-cycles
		Count of all completed GC cycles.

	/gc/gogc:percent
		Heap size target percentage configured by the user, otherwise

		case "/gc/heap/frees:objects":
			objects.frees = samples[i].Value.Uint64()
		case "/gc/heap/frees-by-size:bytes":
			objects.free = samples[i].Value.Float64Histogram()
		case "/gc/cycles:gc-cycles":
			gc.numGC = samples[i].Value.Uint64()
		case "/gc/pauses:seconds":
			h := samples[i].Value.Float64Histogram()
			gc.pauses = 0
			for i := range h.Counts {
				gc.pauses += h.Counts[i]
			}
		case "/gc/scan/heap:bytes":

func (gc *GarbageCollector) processAttemptToDeleteWorker(ctx context.Context) bool {
	item, quit := gc.attemptToDelete.Get()
	gc.workerLock.RLock()
	defer gc.workerLock.RUnlock()
	if quit {
		return false
	}
	defer gc.attemptToDelete.Done(item)

	action := gc.attemptToDeleteWorker(ctx, item)
	switch action {
	case forgetItem:
		gc.attemptToDelete.Forget(item)
	case requeueItem:

	},
	{
		Name:        "/gc/scan/stack:bytes",
		Description: "The number of bytes of stack that were scanned last GC cycle.",
		Kind:        KindUint64,
	},
	{
		Name:        "/gc/scan/total:bytes",
		Description: "The total amount space that is scannable. Sum of all metrics in /gc/scan.",
		Kind:        KindUint64,
	},
	{
		Name:        "/gc/stack/starting-size:bytes",

	// This package only handles gc export data.
	if runtime.Compiler != "gc" {
		t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
	}

	compileAndImportPkg(t, "issue15920")
}

func TestIssue20046(t *testing.T) {
	testenv.MustHaveGoBuild(t)

	// This package only handles gc export data.
	if runtime.Compiler != "gc" {

	// instance, on a system with 32 Ps but only 1 running goroutine, each GC will have
	// 8 dedicated GC workers. Assuming the GC cycle is half mark phase and half sweep
	// phase, then the GC CPU utilization over that cycle, with idle time removed, will
	// be 8/(8+2) = 80%. Even though the limiter turns on, though, assist should be
	// unnecessary, as the GC has way more CPU time to outpace the 1 goroutine that's
	// running.

	// Test that runtime.GC() triggers a GC even if GOGC=off.
	defer debug.SetGCPercent(debug.SetGCPercent(-1))

	var ms1, ms2 runtime.MemStats
	runtime.ReadMemStats(&ms1)
	runtime.GC()
	runtime.ReadMemStats(&ms2)
	if ms1.NumGC == ms2.NumGC {
		t.Fatalf("runtime.GC() did not trigger GC")
	}
	if ms1.NumForcedGC == ms2.NumForcedGC {
		t.Fatalf("runtime.GC() was not accounted in NumForcedGC")
	}
}