[PATCH 0/3] RFC: Implement MemoryWorkingSetExInformation.

[Andrew Wesie]

On Tue, Dec 17, 2019 at 8:07 PM Ken Thomases <ken at codeweavers.com> wrote:
>
> Are the semantics of the fields of MEMORY_WORKING_SET_EX_BLOCK documented or explained somewhere?  It's hard to comment intelligently without that.
>

Not really. My knowledge is limited to what my test has shown:
 - Demand-zero page is "Invalid"
 - Once you read from a demand-zero page (or write to it), it is now "Valid"
 - If you change a page protection to NOACCESS or GUARD, it is "Invalid"
 - If you change a page protection from NOACCESS or GUARD to
READ_ONLY, READWRITE, ... without GUARD, it is still "Invalid"
 - If you then read from that page (or write to it), it is now "Valid"

Those are the semantics that I am having a difficult time replicating
on Linux without causing additional faults. /proc/pid/pagemap lets us
handle the demand-zero page, which is most the common case.

-Andrew