Re: [PATCH 0/3] bitmap: Convert test_bitmap to kunit test

[Muhammad Usama Anjum <usama.anjum@collabora.com>]

On 7/27/24 11:10 PM, Yury Norov wrote:
> On Fri, Jul 26, 2024 at 01:26:48PM -0600, Shuah Khan wrote:
>> On 7/26/24 05:06, Muhammad Usama Anjum wrote:
>>> In this series, test_bitmap is being converted to kunit test. Multiple
>>> patches will make the review process smooth.
>>>
>>> - Patch-1: Convert the tests in lib/test_bitmap.c to kunit
>>> - Patch-2: Rename the lib/test_bitmap.c to lib/bitmap_kunit.c and other
>>>             configuration options
>>> - Patch-3: Remove the bitmap.sh selftest
>>>
>>> Muhammad Usama Anjum (3):
>>>    bitmap: convert test_bitmap to KUnit test
>>>    bitmap: Rename module
>>>    selftests: lib: remove test_bitmap
>>>
>>>   MAINTAINERS                           |   2 +-
>>>   lib/Kconfig.debug                     |  15 +-
>>>   lib/Makefile                          |   2 +-
>>>   lib/{test_bitmap.c => bitmap_kunit.c} | 624 ++++++++++++--------------
>>>   tools/testing/selftests/lib/Makefile  |   2 +-
>>>   tools/testing/selftests/lib/bitmap.sh |   3 -
>>>   tools/testing/selftests/lib/config    |   1 -
>>>   7 files changed, 295 insertions(+), 354 deletions(-)
>>>   rename lib/{test_bitmap.c => bitmap_kunit.c} (70%)
>>>   delete mode 100755 tools/testing/selftests/lib/bitmap.sh
>>>
>>
>> Can you tell me how this conversion helps?
>>
>> It is removing the ability to run bitmap tests during boot.
>> It doesn't make sense to blindly convert all test under lib
>> to kunit - Nack on this change or any change that takes away
>> the ability to run tests and makes them dependent on kunit.
> 
> Hi Muhammad,
> 
> In addition to Shuah's and John's reasoning. This patch wipes the
> test history (git blame will point on you for most of the test),
When files are renamed, their history isn't lost. We just need to use
--follow option with git log to get complete history[1].

> breaks boot-time testing support, messes with config names and
> usability, and drops kselftest support for ... exactly, what?
AFAIU the kselftest wasn't detected the test results that's why I started
thinking on which could be best way to detect if any failure happens in
this test. Triggering the test from kselftest doesn't grantee the test it
would pass every time until we check results. For this kind of in-kernel
testing, kunit is best suites. Please find earlier discussion [2].

> 
> KUNIT engine here doesn't improve on readability, neither shorten
> the test length, to my taste.
> 
> If you'd like to contribute to bitmaps testing - I'm all for that.
> This is the very core and performance-sensitive piece of kernel,
> and any extra-coverage is always welcome.
> 
> But I think the best way would be either adding new cases to the
> existing test, or writing a new test, KUNIT-based, if you like.
> 

[1] https://git-scm.com/docs/git-log#Documentation/git-log.txt---follow
[2]
https://lore.kernel.org/all/327831fb-47ab-4555-8f0b-19a8dbcaacd7@collabora.com

> Thanks,
> Yury
> 

-- 
BR,
Muhammad Usama Anjum