> there's no intrinsic value to your stronger definition of zero-copy > A direct mapping to memory is not always optimal for performance. You comment seems to

> there's no intrinsic value to your stronger definition of zero-copy > A direct mapping to memory is not always optimal for performance. You comment seems to imply that the first statement follows from the second, but it does not. You're right, a direct memory mapping might not be optimal in some situations, but then again in some others it might be optimal. So this feature isn't always useful to everyone, but it doesn't follow that it's never useful to anyone. Even if you worked on this on a range of projects at Google, isn't it possible that there are people working on systems that have rather different performance characteristics than Google's systems?