Re: [PATCH v4 5/5] selftests/mm: add UFFDIO_MOVE ioctl test

[Suren Baghdasaryan]

On Mon, Oct 30, 2023 at 1:35 PM Peter Xu <peterx@xxxxxxxxxx> wrote:
>
> On Mon, Oct 30, 2023 at 01:22:02PM -0700, Suren Baghdasaryan wrote:
> > > > +static int adjust_page_size(void)
> > > > +{
> > > > +     page_size = default_huge_page_size();
> > >
> > > This is hacky too, currently page_size is the real page_size backing the
> > > memory.
> > >
> > > To make thp test simple, maybe just add one more test to MOVE a large chunk
> > > to replace the thp test, which may contain a few thps?  It also doesn't
> > > need to be fault based.
> >
> > Sorry, I didn't get your suggestion. Could you please clarify? Which
> > thp test are you referring to?
>
> The new "move-pmd" test.
>
> I meant maybe it makes sense to have one separate MOVE test for when one
> ioctl(MOVE) covers a large range which can cover some thps.  Then that will
> trigger thp paths.  Assuming the fault paths are already covered in the
> generic "move" test.

Oh, you mean I should not share uffd_move_test() between move and
move-pmd test and have separate logic instead that does not rely on
the page_size overrides? If so then I think that's doable. Some more
code but probably cleaner.

>
> Thanks,
>
> --
> Peter Xu
>