// MADV_FREE_REUSE is necessary to keep the kernel's accounting
	// accurate. If called on any memory region that hasn't been
	// MADV_FREE_REUSABLE'd, it's a no-op.
	madvise(v, n, _MADV_FREE_REUSE)
}

func sysHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
}

			exit(2)
		}
		return nil
	}
	return p
}

func sysUnusedOS(v unsafe.Pointer, n uintptr) {
	madvise(v, n, _MADV_DONTNEED)
}

func sysUsedOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
}

	if debug.madvdontneed != 0 {
		madvise(v, n, _MADV_DONTNEED)
	} else {
		madvise(v, n, _MADV_FREE)
	}
}

func sysUsedOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
}

	} else {
		memFree(v, n)
		memCheck()
	}
	unlock(&memlock)
}

func sysUnusedOS(v unsafe.Pointer, n uintptr) {
}

func sysUsedOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
}

func sysMapOS(v unsafe.Pointer, n uintptr) {

			default:
				print("runtime: VirtualAlloc of ", small, " bytes failed with errno=", errno, "\n")
				throw("runtime: failed to commit pages")
			}
		}
		v = add(v, small)
		k -= small
	}
}

func sysHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
}

func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
}

		if err == _ENOMEM {
			throw("runtime: out of memory")
		}
		if p != v || err != 0 {
			throw("runtime: cannot remap pages in address space")
		}
		return
	}
}

func sysHugePageOS(v unsafe.Pointer, n uintptr) {
	if physHugePageSize != 0 {
		// Round v up to a huge page boundary.
		beg := alignUp(uintptr(v), physHugePageSize)
		// Round v+n down to a huge page boundary.

// hint to the OS that it would be more efficient to back this memory region
// with pages of a larger size transparently.
func sysHugePage(v unsafe.Pointer, n uintptr) {
	sysHugePageOS(v, n)
}

// sysNoHugePage does not transition memory regions, but instead provides a
// hint to the OS that it would be less efficient to back this memory region
// with pages of a larger size transparently.