// See issue 9174.
//
//go:systemstack
func persistentalloc1(size, align uintptr, sysStat *sysMemStat) *notInHeap {
	const (
		maxBlock = 64 << 10 // VM reservation granularity is 64K on windows
	)

	if size == 0 {
		throw("persistentalloc: size == 0")
	}
	if align != 0 {
		if align&(align-1) != 0 {
			throw("persistentalloc: align is not a power of 2")
		}
		if align > _PageSize {

	sysStat *sysMemStat
}

func (a *addrRanges) init(sysStat *sysMemStat) {
	ranges := (*notInHeapSlice)(unsafe.Pointer(&a.ranges))
	ranges.len = 0
	ranges.cap = 16
	ranges.array = (*notInHeap)(persistentalloc(unsafe.Sizeof(addrRange{})*uintptr(ranges.cap), goarch.PtrSize, sysStat))
	a.sysStat = sysStat
	a.totalBytes = 0
}

// findSucc returns the first index in a such that addr is

	stack lfstack
}

// alloc tries to grab a spanSetBlock out of the pool, and if it fails
// persistentallocs a new one and returns it.
func (p *spanSetBlockAlloc) alloc() *spanSetBlock {
	if s := (*spanSetBlock)(p.stack.pop()); s != nil {
		return s
	}
	return (*spanSetBlock)(persistentalloc(unsafe.Sizeof(spanSetBlock{}), cpu.CacheLineSize, &memstats.gcMiscSys))
}

// to these types must always fail the `runtime.inheap` check. The type may be used
// for global variables, or for objects in unmanaged memory (e.g., allocated with
// `sysAlloc`, `persistentalloc`, r`fixalloc`, or from a manually-managed span).
//
// Specifically:
//
// 1. `new(T)`, `make([]T)`, `append([]T, ...)` and implicit heap
// allocation of T are disallowed. (Though implicit allocations are

	for _, ai := range mheap_.allArenas {
		arena := mheap_.arenas[ai.l1()][ai.l2()]
		bitmap := arena.checkmarks

		if bitmap == nil {
			// Allocate bitmap on first use.
			bitmap = (*checkmarksMap)(persistentalloc(unsafe.Sizeof(*bitmap), 0, &memstats.gcMiscSys))
			if bitmap == nil {
				throw("out of memory allocating checkmarks bitmap")
			}
			arena.checkmarks = bitmap
		} else {
			// Otherwise clear the existing bitmap.

		v := unsafe.Pointer(f.list)
		f.list = f.list.next
		f.inuse += f.size
		if f.zero {
			memclrNoHeapPointers(v, f.size)
		}
		return v
	}
	if uintptr(f.nchunk) < f.size {
		f.chunk = uintptr(persistentalloc(uintptr(f.nalloc), 0, f.stat))
		f.nchunk = f.nalloc
	}

	v := unsafe.Pointer(f.chunk)
	if f.first != nil {
		f.first(f.arg, v)
	}
	f.chunk = f.chunk + f.size
	f.nchunk -= uint32(f.size)

// outside the Go heap.
// We require lfstack objects to live outside the heap so that
// checkptr passes on the unsafe shenanigans used.
func allocMyNode(data int) *MyNode {
	n := (*MyNode)(PersistentAlloc(unsafe.Sizeof(MyNode{})))
	LFNodeValidate(&n.LFNode)
	n.data = data
	return n
}

func fromMyNode(node *MyNode) *LFNode {
	return (*LFNode)(unsafe.Pointer(node))
}

func toMyNode(node *LFNode) *MyNode {

* sysAlloc obtains memory directly from the OS. This comes in whole
  multiples of the system page size, but it can be freed with sysFree.

* persistentalloc combines multiple smaller allocations into a single
  sysAlloc to avoid fragmentation. However, there is no way to free
  persistentalloced objects (hence the name).

* fixalloc is a SLAB-style allocator that allocates objects of a fixed

		}
		// The first word of an interface is a pointer, but we don't
		// treat it as such.
		// 1. If it is a non-empty interface, the pointer points to an itab
		//    which is always in persistentalloc space.
		// 2. If it is an empty interface, the pointer points to a _type.
		//   a. If it is a compile-time-allocated type, it points into
		//      the read-only data section.

}

func FrameStartLine(f *Frame) int {
	return f.startLine
}

// PersistentAlloc allocates some memory that lives outside the Go heap.
// This memory will never be freed; use sparingly.
func PersistentAlloc(n uintptr) unsafe.Pointer {
	return persistentalloc(n, 0, &memstats.other_sys)
}

// FPCallers works like Callers and uses frame pointer unwinding to populate