Re: [PATCH] selftests: sched: add sched as a default selftest target

[Shan <sinadin.shan@oracle.com>]

On 20-02-2025 09:26 pm, Chris Hyser wrote:
> From: Sinadin Shan <sinadin.shan@oracle.com>
> Sent: Thursday, February 20, 2025 9:52 AM
> To: Shrikanth Hegde; Chris Hyser
> Cc: linux-kselftest@vger.kernel.org; linux-kernel@vger.kernel.org; shuah@kernel.org
> Subject: Re: [PATCH] selftests: sched: add sched as a default selftest target
> 
>> On 20-02-2025 01:15 pm, Shrikanth Hegde wrote:
>>
>>> If CONFIG_SCHED_CORE=n, the test fails. So you might end up seeing
>>> default selftests failing on such systems? or this is only compiling?>
>>
>> Yes, this patch would enable the test to be compiled and run by default.
>>
>>> Likely the selftests/sched needs to modified for CONFIG_SCHED_CORE=n
>>
>> Agree. Chris, I suppose then a graceful skip would be a more right
>> option for kernels with core scheduling disabled?
> 
> By graceful skip, do you mean a 0 return code and not printing failure? I confess,
> I originally wrote the test as stand-alone for me to get the prctl code right and it
> got shoved in here.

By graceful skip, I meant printing that SCHED_CORE is disabled for the 
kernel and exiting with a return code 4 on such kernels. This would also 
make the kselftest framework pick up the skip, say when compiled tests 
are run through run_kselftest.sh

> 
> I guess my question is what if SCHED_CORE was supposed to be configed into
> the test kernel?  Silently burying the error might be bad. I'm not strongly tied to
> that, just looking for opinions. At the same time, if you put the orig change in,
> people w/o SCHED_CORE on will start seeing "failures" they didn't see before,
> yes? and that seems bad.

Yes, that seems bad as rightly pointed out by Shrikant. I have a patch 
that does the above mentioned skip, and if skipping is a right option to 
take here I can send it in the next version.

Regards,
Shan
> 
> I'm happy to make this better behaved. I'm the reason it is the way it is.
> 
> -chrish
> 
>