Re: [PATCH] Snapshot of shared page tables

[Paul Mackerras]

Dave McCracken writes:

> Ok, here it is.  This patch works for my simple tests, both under UP and
> SMP, including under memory pressure.  I'd appreciate anyone who'd like to
> take it and beat on it.  Please let me know of any problems you find.

Interesting.  I notice that you are using the _PAGE_RW bit in the
PMDs.  Are you relying on the hardware to do anything with that bit,
or is it only used by software?

(If you are relying on the hardware to do something different when
_PAGE_RW is clear in the PMD, then your approach isn't portable.)

Paul.