Re: [PATCH v3 30/48] mm/damon: Stop using vma_mas_store() for maple tree store

[Daniel Latypov]

On Tue, Jan 17, 2023 at 11:11 AM SeongJae Park <sj@xxxxxxxxxx> wrote:
>
> Cc-ing kunit people.
>
> Hi Liam,
>
>
> Could we put touching file name on the summary?
> E.g., mm/damon/vaddr-test: Stop using ...
>
> On Tue, 17 Jan 2023 02:34:19 +0000 Liam Howlett <liam.howlett@xxxxxxxxxx> wrote:
>
> > From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
> >
> > Prepare for the removal of the vma_mas_store() function by open coding
> > the maple tree store in this test code.  Set the range of the maple
> > state and call the store function directly.
> >
> > Cc: SeongJae Park <sj@xxxxxxxxxx>
> > Cc: damon@xxxxxxxxxxxxxxx
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> > ---
> >  mm/damon/vaddr-test.h | 19 +++++++++++++------
> >  1 file changed, 13 insertions(+), 6 deletions(-)
> >
> > diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
> > index bce37c487540..6098933d3272 100644
> > --- a/mm/damon/vaddr-test.h
> > +++ b/mm/damon/vaddr-test.h
> > @@ -14,19 +14,26 @@
> >
> >  #include <kunit/test.h>
> >
> > -static void __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
> > +static int __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
> >                       ssize_t nr_vmas)
> >  {
> > -     int i;
> > +     int i, ret = -ENOMEM;
> >       MA_STATE(mas, mt, 0, 0);
> >
> >       if (!nr_vmas)
> > -             return;
> > +             return -ENOENT;

We could pass in the `test` object here and give more detailed info, e.g.
  (if !nr_vmas)
     kunit_skip(test, "...");

And below could be

bool stored_all = false; // instead of ret
...
for (...) {

}
stored_all = true;

failed:
  mas_unlock(&mas);
  if (!stored_all) kunit_skip(test, "failed to...");

> >
> >       mas_lock(&mas);
> > -     for (i = 0; i < nr_vmas; i++)
> > -             vma_mas_store(&vmas[i], &mas);
> > +     for (i = 0; i < nr_vmas; i++) {
> > +             mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
> > +             if (mas_store_gfp(&mas, &vmas[i], GFP_KERNEL))
> > +                     goto failed;
> > +     }
> > +     ret = 0;
> > +
> > +failed:
> >       mas_unlock(&mas);
> > +     return ret;
> >  }
> >
> >  /*
> > @@ -71,7 +78,7 @@ static void damon_test_three_regions_in_vmas(struct kunit *test)
> >       };
> >
> >       mt_init_flags(&mm.mm_mt, MM_MT_FLAGS);
> > -     __link_vmas(&mm.mm_mt, vmas, ARRAY_SIZE(vmas));
> > +     KUNIT_EXPECT_EQ(test, __link_vmas(&mm.mm_mt, vmas, ARRAY_SIZE(vmas)), 0);
>
> In case of the __link_vmas() failure, I think we should skip this test using
> 'kunit_skip()', rather marking this test failed.

As noted above, I'd suggest we also pass in the `test` object to
__link_vmas() and call kunit_skip() from there.

>
>
> Thanks,
> SJ

Daniel