osStackFree(s)
				mheap_.freeManual(s, spanAllocStack)
			}
			s = next
		}
		unlock(&stackpool[order].item.mu)
	}

	// Free large stack spans.
	lock(&stackLarge.lock)
	for i := range stackLarge.free {
		for s := stackLarge.free[i].first; s != nil; {
			next := s.next
			stackLarge.free[i].remove(s)
			osStackFree(s)
			mheap_.freeManual(s, spanAllocStack)
			s = next
		}

		gp := getg().m.curg
		for i := 0; i < batchSize && !(preemptible && gp.preempt); i++ {
			span := work.wbufSpans.free.first
			if span == nil {
				break
			}
			work.wbufSpans.free.remove(span)
			mheap_.freeManual(span, spanAllocWorkBuf)
		}
	})
	more := !work.wbufSpans.free.isEmpty()
	unlock(&work.wbufSpans.lock)
	return more

		h.freeSpanLocked(s, spanAllocHeap)
		unlock(&h.lock)
	})
}

// freeManual frees a manually-managed span returned by allocManual.
// typ must be the same as the spanAllocType passed to the allocManual that
// allocated s.
//
// This must only be called when gcphase == _GCoff. See mSpanState for
// an explanation.
//
// freeManual must be called on the system stack because it acquires

				// The unrolled GCProg bitmap is allocated separately.
				// Free the space for the unrolled bitmap.
				systemstack(func() {
					s := spanOf(uintptr(unsafe.Pointer(s.largeType)))
					mheap_.freeManual(s, spanAllocPtrScalarBits)
				})
				// Make sure to zero this pointer without putting the old
				// value in a write buffer, as the old value might be an
				// invalid pointer. See arena.go:(*mheap).allocUserArenaChunk.

	s := mheap_.allocManual(pages, spanAllocPtrScalarBits)
	runGCProg(addb(prog, 4), (*byte)(unsafe.Pointer(s.startAddr)))
	return s
}
func dematerializeGCProg(s *mspan) {
	mheap_.freeManual(s, spanAllocPtrScalarBits)
}

func dumpGCProg(p *byte) {
	nptr := 0
	for {
		x := *p
		p = add1(p)
		if x == 0 {
			print("\t", nptr, " end\n")
			break
		}