Re: [PATCH 1/2] selftests/damon: test no-op commit broke DAMON status

[Sang-Heon Jeon <ekffu200098@gmail.com>]

Hi SeongJae

On Sun, Aug 10, 2025 at 2:36 AM SeongJae Park <sj@kernel.org> wrote:
>
> On Sat, 9 Aug 2025 15:39:41 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
>
> > Hi SeongJae
> >
> > On Sat, Aug 9, 2025 at 7:05 AM SeongJae Park <sj@kernel.org> wrote:
> > >
> > > Hello Sang-Heon,
> > >
> > > On Sat,  9 Aug 2025 04:55:17 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> > >
> > > > Add test to verify that DAMON status is not changed after a no-op
> > > > commit.
> > >
> > > Thank you for this patch!  I have some comments below, though.
> > >
> > > > Currently, it is failing. but after fix the bug it should be
> > > > success.
> > >
> > > To keep bisecting goes smoothly, let's introduce failing tests _after_ their
> > > fixes are landed.
> >
> > I see. As mentioned in another comment, I'll merge this patch set into
> > one patch. I think this comment will be resolved then.
>
> That could make the patch be unnecessarily difficult to apply on older kernels
> due to the test part.  Please keep those separated.

Oh, I misunderstand your previous comment. Now, I understand your
point. I'll separate them back and make two v3 patch(one for fix bug,
one for test) not a patch set.
Thanks for the explanation, I feel like I'm learning more and more.

> [...]
> > > > +    if rc != 0:
> > > > +        return None, f'drgn fail : return code({rc})'
> > >
> > > Let's not add a space before ':', for the consistency.
> >
> > I see. I made so many mistakes like these; (I worked this very late
> > night...) I will fix them all. Thank you for checking this moment.
>
> I'm sorry to hear that you had to work on late night :'(  I hope you to have
> sufficient rests.

Never mind. just I went with that :) Thanks as always.

> [...]
> > To be honest, I didn't use kselftest framework while making these
> > patch set because I don't know how kernel developers use it.
> >
> > If you are okay, could you share how you use it?
>
> Sure.  I do below for running DAMON selftests.
>
>     $ sudo make -C tools/testing/selftests/damon run_tsets
>
> You could also run DAMON kunit tests like below.
>
>     $ ./tools/testing/kunit/kunit.py run --kunitconfig mm/damon/tests/

Thanks for sharing. I'll try it with my vm environment.

> I usually run all those together with additional tests, using DAMON tests
> suite[2].
>
> > I just build kernel
> > with custom patch, and execute output images by vm, and setup env,
> > then just execute tests(it's so raw.. i know)
>
> It's ok.  No one fits all, so different tests are needed for different hacks.
> Please keep using whatever works best for you :)

You're so right. Maybe I just want to learn some tips from the experts. haha

> >
> > Maybe is there a kernel build option that automatically includes tests
> > to output image? Or just a general or smarter way to execute the whole
> > test?
>
> To be honest I'm also not an expert of kselftest and kunit :)  You coule refer
> to the kselftest documentation[1] for more details.

Thanks for sharing!

> [...]
> > Thanks for reviewing! Have a nice weekend. I'll do this job after my
> > personal schedule finishes.
>
> No worry, take your time and fun! :)
> [...]

:)

> [1] https://docs.kernel.org/dev-tools/kselftest.html
> [2] https://github.com/damonitor/damon-tests/blob/master/corr/run.sh
>
>
> Thanks,
> SJ

Best Regards.
Sang-Heon Jeon