Re: [PATCH 1/4] selftests/mm/uffd: Refactor non-composite global vars into struct

[Andrew Morton <akpm@linux-foundation.org>]

On Sat, 3 May 2025 23:46:26 +0530 Ujwal Kundur <ujwal.kundur@gmail.com> wrote:

> Thanks for the review and testing!
> 
> I'll push a V2 with the indentation fixes soon.
> 
> > this deletes the global vars before it deletes
> > the references to them. That's gonna be a real pain for bisections,
> > please can you restructure the series to prevent intervening build
> > failures?
> > (i.e. if I apply just 1/4, the selftests don't compile).
> 
> Could you help me understand this better? The selftests don't compile
> either way if both 1 and 2/3/4 aren't applied at the same time.
> 

At present uffd-stress, uffd-unit-tests and uffd-wp-mremap compile
successfuly.  After adding your [1/4] patch they do not.

This is undesirable because such an inter-series build breakage makes
it harder for people to perform git-bisect regression searches - if the
bisection point lands within this series, their build fails.

Probably this isn't very important in selftests/mm.

One could perhaps change [1/4] to provide back-compatibility defines
such as

	#define test_uffdio_wp gopts->test_uffdio_wp

then remove those at the end of the series.  But this is just too much
fuss and will probably cause other issues

I suggest you convert this series into a single patch.