[PATCH] xarray: port tests to kunit

[Matthew Wilcox]

On Thu, Jan 30, 2025 at 09:21:12AM +0100, Geert Uytterhoeven wrote:
> The long and obscure command line is a red herring: a simple
> "modprobe test_xarray" is all it takes...

That's all I've ever done.  I'm confused/annoyed by all this "let's
wrap everything up in some complex and obscure new thing" practice.

> > You should look at the userspace testing (that this broke) as it has
> > been really useful in certain scenarios.
> 
> BTW, how do I even build tools/testing/radix-tree?
> "make tools/help" doesn't show the radix-tree test.
> "make tools/all" doesn't seem to try to build it.
> Same for "make kselftest-all".

I've never heard of any of those things.  So I didn't try to make any of
them work.

> When trying the above, and ignoring failures due to missing packages
> on my host:
>   - there are several weird build errors,
>   - this doesn't play well with O=,
>   - lots of scary warnings when building for 32-bit,
>   - ...

Really?  Turns out I haven't built for 32-bit on this laptop, so I'm
installing all the packages I need now.  I seem to reemember it being
painful due to liburcu packaging not allowing me to install both a
32-bit and 64-bit package at the same time.

> At least the kunit tests build (and run[1] ;-) most of the time...

That's unworthy.  kunit isn't trying to do anything nearly as hard
as the radix tree tests are.

> [1] test_xarray started failing on m68k recently
>     https://lore.kernel.org/all/CAMuHMdU_bfadUO=0OZ=AoQ9EAmQPA4wsLCBqohXR+QCeCKRn4A@mail.gmail.com/

I really wish Andrew would stop merging xarray patches.