retry:
	if gcCPULimiter.limiting() {
		// If the CPU limiter is enabled, intentionally don't
		// assist to reduce the amount of CPU time spent in the GC.
		if enteredMarkAssistForTracing {
			trace := traceAcquire()
			if trace.ok() {
				trace.GCMarkAssistDone()
				// Set this *after* we trace the end to make sure
				// that we emit an in-progress event if this is
				// the first event for the goroutine in the trace

	// goroutineProfiled field cleared.
	forEachGRace(func(gp1 *g) {
		gp1.goroutineProfiled.Store(goroutineProfileAbsent)
	})

	if raceenabled {
		raceacquire(unsafe.Pointer(&labelSync))
	}

	if n != int(endOffset) {
		// It's a big surprise that the number of goroutines changed while we
		// were collecting the profile. But probably better to return a

		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

}

func Read(fd int, p []byte) (n int, err error) {
	n, err = read(fd, p)
	if raceenabled {
		if n > 0 {
			raceWriteRange(unsafe.Pointer(&p[0]), n)
		}
		if err == nil {
			raceAcquire(unsafe.Pointer(&ioSync))
		}
	}
	return
}

func Write(fd int, p []byte) (n int, err error) {
	if raceenabled {
		raceReleaseMerge(unsafe.Pointer(&ioSync))
	}
	n, err = write(fd, p)