Re: [RFC v3 3/7] mm: Use seprintf() instead of less ergonomic APIs

[Marco Elver <elver@google.com>]

On Mon, 7 Jul 2025 at 20:51, Alejandro Colomar <alx@kernel.org> wrote:
>
> Hi Marco,
>
> On Mon, Jul 07, 2025 at 04:58:53PM +0200, Marco Elver wrote:
> > Feel free to make it warning-free, I guess that's useful.
>
> Thanks!
>
> > > > Did you run the tests? Do they pass?
> > >
> > > I don't know how to run them.  I've only built the kernel.  If you point
> > > me to instructions on how to run them, I'll do so.  Thanks!
> >
> > Should just be CONFIG_KFENCE_KUNIT_TEST=y -- then boot kernel and
> > check that the test reports "ok".
>
> Hmmm, I can't see the results.  Did I miss anything?
>
>         alx@debian:~$ uname -a
>         Linux debian 6.15.0-seprintf-mm+ #5 SMP PREEMPT_DYNAMIC Mon Jul  7 19:16:40 CEST 2025 x86_64 GNU/Linux
>         alx@debian:~$ cat /boot/config-6.15.0-seprintf-mm+ | grep KFENCE
>         CONFIG_HAVE_ARCH_KFENCE=y
>         CONFIG_KFENCE=y
>         CONFIG_KFENCE_SAMPLE_INTERVAL=0

                     ^^ This means KFENCE is off.

Not sure why it's 0 (distro default config?), but if you switch it to
something like:

  CONFIG_KFENCE_SAMPLE_INTERVAL=10

The test should run. Alternatively set 'kfence.sample_interval=10' as
boot param.

>         CONFIG_KFENCE_NUM_OBJECTS=255
>         # CONFIG_KFENCE_DEFERRABLE is not set
>         # CONFIG_KFENCE_STATIC_KEYS is not set
>         CONFIG_KFENCE_STRESS_TEST_FAULTS=0
>         CONFIG_KFENCE_KUNIT_TEST=y
>         alx@debian:~$ sudo dmesg | grep -i kfence
>         alx@debian:~$
>
> I see a lot of new stuff in dmesg, but nothing with 'kfence' in it.
>
>
> Cheers,
> Alex
>
> --
> <https://www.alejandro-colomar.es/>