// susceptible to collection.
	big = nil

	// FreeOSMemory runs a GC cycle before releasing memory,
	// so it's fine to skip a GC here.
	//
	// It's possible the background scavenger runs concurrently
	// with this function and does most of the work for it.
	// If that happens, it's OK. What we want is a test that fails
	// often if FreeOSMemory does not work correctly, and a test
	// that passes every time if it does.

// license that can be found in the LICENSE file.

package debug

import (
	"time"
)

// Implemented in package runtime.
func readGCStats(*[]time.Duration)
func freeOSMemory()
func setMaxStack(int) int
func setGCPercent(int32) int32
func setPanicOnFault(bool) bool
func setMaxThreads(int) int

func SetGCPercent(percent int) int {
	return int(setGCPercent(int32(percent)))
}

// FreeOSMemory forces a garbage collection followed by an
// attempt to return as much memory to the operating system
// as possible. (Even if this is not called, the runtime gradually
// returns memory to the operating system in a background task.)
func FreeOSMemory() {
	freeOSMemory()
}

// SetMaxStack sets the maximum amount of memory that

		#% util            the fraction of all unscavenged heap memory which is in-use
	If the line ends with "(forced)", then scavenging was forced by a
	debug.FreeOSMemory() call.

	scheddetail: setting schedtrace=X and scheddetail=1 causes the scheduler to emit
	detailed multiline info every X milliseconds, describing state of the scheduler,
	processors, threads and goroutines.

// that a chunk that just became dense is scavenged in the case of a race between memory
// allocation and scavenging.
//
// When synchronously scavenging for the memory limit or for debug.FreeOSMemory, these
// "dense" packing heuristics are ignored (in other words, scavenging is "forced") because
// in these scenarios returning memory to the OS is more important than keeping CPU
// overheads low.

package runtime

	// Let's make sure there's no background scavenge work to do.
	//
	// The runtime.GC calls below ensure the background sweeper
	// will not run during the idle period.
	debug.FreeOSMemory()

	for retries := 0; retries < maxFailures; retries++ {
		// Read 1.
		runtime.GC() // Update /cpu/classes metrics.
		metrics.Read(m1)

		// Sleep.
		time.Sleep(dur)

		// Read 2.

	gp.m.mallocing--

	if debug.scavtrace > 0 {
		printScavTrace(0, released, true)
	}
}

//go:linkname runtime_debug_freeOSMemory runtime/debug.freeOSMemory
func runtime_debug_freeOSMemory() {
	GC()
	systemstack(func() { mheap_.scavengeAll() })
}

// Initialize a new span with the given start and npages.

		{"BuildInfo.Path", Field, 12},
		{"BuildInfo.Settings", Field, 18},
		{"BuildSetting", Type, 18},
		{"BuildSetting.Key", Field, 18},
		{"BuildSetting.Value", Field, 18},
		{"FreeOSMemory", Func, 1},
		{"GCStats", Type, 1},
		{"GCStats.LastGC", Field, 1},
		{"GCStats.NumGC", Field, 1},
		{"GCStats.Pause", Field, 1},
		{"GCStats.PauseEnd", Field, 4},
		{"GCStats.PauseQuantiles", Field, 1},

pkg runtime, type BlockProfileRecord struct, Count int64
pkg runtime, type BlockProfileRecord struct, Cycles int64
pkg runtime, type BlockProfileRecord struct, embedded StackRecord
pkg runtime/debug, func FreeOSMemory()
pkg runtime/debug, func ReadGCStats(*GCStats)
pkg runtime/debug, func SetGCPercent(int) int
pkg runtime/debug, type GCStats struct
pkg runtime/debug, type GCStats struct, LastGC time.Time