cpuprofile        = flag.String("cpuprofile", "", "write cpu profile to `file`")
	memprofile        = flag.String("memprofile", "", "write memory profile to `file`")
	memprofilerate    = flag.Int64("memprofilerate", 0, "set runtime.MemProfileRate to `rate`")
	benchmarkFlag     = flag.String("benchmark", "", "set to 'mem' or 'cpu' to enable phase benchmarking")

		if seen[key] {
			continue
		}
		if seen != nil {
			seen[key] = true
		}

		// Update MemProfileRate directly here since it
		// is int, not int32, and should only be updated
		// if specified in GODEBUG.
		if seen == nil && key == "memprofilerate" {
			if n, ok := atoi(value); ok {
				MemProfileRate = n
			}
		} else {
			for _, v := range dbgvars {
				if v.name == key {

	of MADV_FREE. This is less efficient, but causes RSS numbers to drop
	more quickly.

	memprofilerate: setting memprofilerate=X will update the value of runtime.MemProfileRate.
	When set to 0 memory profiling is disabled.  Refer to the description of
	MemProfileRate for the default value.

	profstackdepth: profstackdepth=128 (the default) will set the maximum stack

		total.FreeBytes += r.FreeBytes
		total.FreeObjects += r.FreeObjects
	}

	// Technically the rate is MemProfileRate not 2*MemProfileRate,
	// but early versions of the C++ heap profiler reported 2*MemProfileRate,
	// so that's what pprof has come to expect.
	rate := 2 * runtime.MemProfileRate

	// pprof reads a profile with alloc == inuse as being a "2-column" profile

	cf.StringVar(&testFuzz, "fuzz", "", "")
	cf.Bool("fullpath", false, "")
	cf.StringVar(&testList, "list", "", "")
	cf.StringVar(&testMemProfile, "memprofile", "", "")
	cf.String("memprofilerate", "", "")
	cf.StringVar(&testMutexProfile, "mutexprofile", "", "")
	cf.String("mutexprofilefraction", "", "")
	cf.Var(&testOutputDir, "outputdir", "")
	cf.Int("parallel", 0, "")
	cf.String("run", "", "")

		for name, buf := range prof.Records() {
			if len(buf) > 0 {
				dst[typ+"-"+name+"."+prof.Extension()] = buf
			}
		}
	}
	return dst, nil
}

func setDefaultProfilerRates() {
	runtime.MemProfileRate = 128 << 10 // 512KB -> 128K - Must be constant throughout application lifetime.
	runtime.SetMutexProfileFraction(0) // Disable until needed
	runtime.SetBlockProfileRate(0)     // Disable until needed
}

		span.userArenaChunkFree = makeAddrRange(span.base(), rzStart)
		asanpoison(unsafe.Pointer(rzStart), span.limit-rzStart)
		asanunpoison(unsafe.Pointer(span.base()), span.elemsize)
	}

	if rate := MemProfileRate; rate > 0 {
		c := getMCache(mp)
		if c == nil {
			throw("newUserArenaChunk called without a P or outside bootstrapping")
		}
		// Note cache c only valid while m acquired; see #47302