On Thu, Jan 10, 2019 at 8:04 PM Dave Chinner [off-list ref] wrote:

So it will only read the single page we tried to access and won't
perturb the rest of the message encoded into subsequent pages in
file.

Dave, you're being intentionally obtuse, aren't you?

It's only that single page that *matters*. That's the page that the
probe reveals the status of - but it's also the page that the probe
then *changes* the status of.

See?

Think of it as "the act of measurement changes that which is
measured". And that makes the measurement pointless.

              Linus