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From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Wed, 20 Mar 2024 09:08:42 +0100
Message-ID: <CAMuHMdVig-cm7KPi76ow9-xyZ55z4YgYrx6QuO9V5A0ni7HxDA@mail.gmail.com>
Subject: Re: [PATCH] scsi: core: Make scsi_lib KUnit tests modular for real
To: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Christie <michael.christie@oracle.com>, 
	"James E . J . Bottomley" <jejb@linux.ibm.com>, "Martin K . Petersen" <martin.petersen@oracle.com>, 
	Lukas Bulwahn <lukas.bulwahn@gmail.com>, linux-scsi@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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Hoi Bart,

CC linux-kselftest@vger.kernel.org

On Tue, Mar 19, 2024 at 6:01=E2=80=AFPM Bart Van Assche <bvanassche@acm.org=
> wrote:
> On 3/19/24 09:10, Geert Uytterhoeven wrote:
> > On Tue, Mar 19, 2024 at 5:03=E2=80=AFPM Bart Van Assche <bvanassche@acm=
org> wrote:
> >> On 3/19/24 05:02, Geert Uytterhoeven wrote:
> >> kernel module? What are the advantages compared to the current approac=
h?
> >> That information is missing from the patch description.
> >
> > SCSI_LIB_KUNIT_TEST is already tristate, so the original author must
> > have meant it to be modular.  Or perhaps he just copied it from
> > (most/all) other tests ;-)
> >
> > Anyway, I find it very useful to be able to do "modprobe kunit" and
> > "modprobe <test>" to run a test when I feel the need to do so.
>
> Why to run hardware-independent kunit tests on the target system instead
> of on the host? Isn't it much more convenient when developing embedded
> software to run kunit tests on the host using UML? The script I use to

Because test results may differ between target and host?
It's not uncommon for supposedly hardware-independent tests to behave
differently on different architectures and platforms, due to subtle
differences in word size, endianness, alignment rules, CPU topology, ...

> run SCSI kunit tests is available below. And if there is a desire to run
> SCSI tests on the target system, how about adding triggers in sysfs for
> running kunit tests? The (GPL v2) Samsung smartphone kernel supports
> this but I have not yet checked whether their implementation is
> appropriate for the upstream kernel.

That would require all tests to be built-in, reducing the amount of memory
(if any remains at all) available to the real application.

Gr{oetje,eeting}s,

                        Geert

--=20
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k=
org

In personal conversations with technical people, I call myself a hacker. Bu=
t
when I'm talking to journalists I just say "programmer" or something like t=
hat.
                                -- Linus Torvalds