Re: [PATCH v4] mm: Add PM_HUGE_THP_MAPPING to /proc/pid/pagemap

From: Peter Xu
Date: Fri Nov 12 2021 - 02:43:35 EST


On Wed, Nov 10, 2021 at 09:50:13AM -0800, Mina Almasry wrote:
> On Tue, Nov 9, 2021 at 11:03 PM Peter Xu <peterx@xxxxxxxxxx> wrote:
> >
> > The ending "_MAPPING" seems redundant to me, how about just call it "PM_THP" or
> > "PM_HUGE" (as THP also means HUGE already)?
> >
>
> So I want to make it clear that the flag is set only when the page is
> PMD mappend and is a THP (not hugetlbfs or some other PMD device
> mapping). PM_THP would imply the flag is set only if the underlying
> page is THP without regard to whether it's actually PMD mapped or not.

I see, that's fine.

However as I mentioned I still think HUGE and THP dup with each other.
Meanwhile, "MAPPING" does not sound like a boolean status on whether it's thp
mapped..

If you still prefer this approach, how about PM_THP_MAPPED?

--
Peter Xu