[Linux-kernel-mentees] [PATCH v2] lib: Convert test_printf.c to KUnit

[Arpitha Raghunandan]

On 23/10/20 11:31 pm, Petr Mladek wrote:
> On Fri 2020-10-23 19:13:00, Arpitha Raghunandan wrote:
>> On 23/10/20 4:36 pm, Rasmus Villemoes wrote:
>>> On 22/10/2020 21.16, Andy Shevchenko wrote:
>>>> On Thu, Oct 22, 2020 at 08:43:49PM +0530, Arpitha Raghunandan wrote:
>>>>> Converted test failure:
>>>>>     # Subtest: printf-kunit-test
>>>>>     1..1
>>>>>     # selftest: EXPECTATION FAILED at lib/printf_kunit.c:82
>>>>> vsnprintf(buf, 256, "%pi4|%pI4", ...) wrote
>>>>> '127.000.000.001|127.0.0.1', expected '127-000.000.001|127.0.0.1'
>>>>>     # selftest: EXPECTATION FAILED at lib/printf_kunit.c:82
>>>>> vsnprintf(buf, 5, "%pi4|%pI4", ...) wrote '127.', expected '127-'
>>>>>     # selftest: EXPECTATION FAILED at lib/printf_kunit.c:118
>>>>> kvasprintf(..., "%pi4|%pI4", ...) returned
>>>>> '127.000.000.001|127.0.0.1', expected '127-000.000.001|127.0.0.1'
>>>>>     not ok 1 - selftest
>>>>> not ok 1 - printf-kunit-test
>>>>
>>>> Not bad. Rasmus, what do you think?
>>>
>>> Much better, but that '1..1' and reporting the entire test suite as 1
>>> single (failing or passing) test is (also) a regression. Look at the
>>> original
>>>
>>>>> [    0.591409] test_printf: all 388 tests passed
>>>
>>> or
>>>
>>>>> [    0.619495] test_printf: failed 3 out of 388 tests
>>>
>>> That's far more informative, and I'd prefer if the summary information
>>> (whether in the all-good case or some-failing) included something like
>>> this. In particular, I have at some point spotted that I failed to
>>> properly hook up a new test case (or perhaps failed to re-compile, or
>>> somehow still ran the old kernel binary, don't remember which it was) by
>>> noticing that the total number of tests hadn't increased. The new output
>>> would not help catch such PEBKACs.
>>>
>>> Rasmus
>>>
>>
>> Splitting the test into multiple test cases in KUnit will display
>> the number and name of tests that pass or fail. This will be similar
>> to the lib/list-test.c test as can be seen here:
>> https://elixir.bootlin.com/linux/latest/source/lib/list-test.c.
>> I will work on this for the next version of this patch.
> 
> We should probably agree on the granularity first.
> 
> It looks like an overkill to split the tests into 388 functions
> and define KUNIT_CASE() lines. It might be possible to hide
> this into macros but macros are hell for debugging.
> 
> I suggest to split it by the current functions that do more test()
> call inside. I mean to define something like:
> 
> static struct kunit_case printf_test_cases[] = {
> 	KUNIT_CASE(basic),
> 	KUNIT_CASE(number),
> 	KUNIT_CASE(string),
> 	KUNIT_CASE(plain_pointer),
> 	KUNIT_CASE(null_poiter),
> 	KUNIT_CASE(error_pointer),
> 	KUNIT_CASE(addr),
> 	KUNIT_CASE(struct_resource),
> 	KUNIT_CASE(dentry),
> 	KUNIT_CASE(pointer_addr),
> 	 ...,
> 	{}
> };
> 
> Best Regards,
> Petr
> 

Okay, I will split it by the current functions that have more test() calls inside as suggested.
I will also make changes as per your other suggestions for the next version.
Thanks!