[PATCH 3/8] drm/sched: Reduce scheduler's timeout for timeout tests

[Maíra Canal]

Hi Tvrtko,

Thanks for your review!

On 06/05/25 09:03, Tvrtko Ursulin wrote:
> 
> On 03/05/2025 21:59, Maíra Canal wrote:
>> As more KUnit tests are introduced to evaluate the basic capabilities of
>> the `timedout_job()` hook, the test suite will continue to increase in
>> duration. To reduce the overall running time of the test suite, decrease
>> the scheduler's timeout for the timeout tests.
>>
>> Before this commit:
>>
>> [15:42:26] Elapsed time: 15.637s total, 0.002s configuring, 10.387s 
>> building, 5.229s running
>>
>> After this commit:
>>
>> [15:45:26] Elapsed time: 9.263s total, 0.002s configuring, 5.168s 
>> building, 4.037s running
>>
>> Signed-off-by: Maíra Canal <mcanal at igalia.com>
>> ---
>>   drivers/gpu/drm/scheduler/tests/tests_basic.c | 10 ++++++----
>>   1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/scheduler/tests/tests_basic.c b/drivers/ 
>> gpu/drm/scheduler/tests/tests_basic.c
>> index 
>> 8f960f0fd31d0af7873f410ceba2d636f58a5474..00c691cb3c306f609684f554f17fcb54ba74cb95 100644
>> --- a/drivers/gpu/drm/scheduler/tests/tests_basic.c
>> +++ b/drivers/gpu/drm/scheduler/tests/tests_basic.c
>> @@ -5,6 +5,8 @@
>>   #include "sched_tests.h"
>> +#define MOCK_TIMEOUT (HZ / 5)
>> +
>>   /*
>>    * DRM scheduler basic tests should check the basic functional 
>> correctness of
>>    * the scheduler, including some very light smoke testing. More 
>> targeted tests,
>> @@ -28,7 +30,7 @@ static void drm_sched_basic_exit(struct kunit *test)
>>   static int drm_sched_timeout_init(struct kunit *test)
>>   {
>> -    test->priv = drm_mock_sched_new(test, HZ);
>> +    test->priv = drm_mock_sched_new(test, MOCK_TIMEOUT);
>>       return 0;
>>   }
>> @@ -224,17 +226,17 @@ static void drm_sched_basic_timeout(struct kunit 
>> *test)
>>       drm_mock_sched_job_submit(job);
>> -    done = drm_mock_sched_job_wait_scheduled(job, HZ);
>> +    done = drm_mock_sched_job_wait_scheduled(job, MOCK_TIMEOUT);
> 
> This wait is accounting for the fact sched->wq needs to run and call - 
>  >run_job() before job will become scheduled. It is not related to 
> timeout handling. I was going for a safe value and I think decreasing it 
> will not speed up the test but may cause sporadic failures.

I'll address it in v2.

> 
>>       KUNIT_ASSERT_TRUE(test, done);
>> -    done = drm_mock_sched_job_wait_finished(job, HZ / 2);
>> +    done = drm_mock_sched_job_wait_finished(job, MOCK_TIMEOUT / 2);
>>       KUNIT_ASSERT_FALSE(test, done);
>>       KUNIT_ASSERT_EQ(test,
>>               job->flags & DRM_MOCK_SCHED_JOB_TIMEDOUT,
>>               0);
>> -    done = drm_mock_sched_job_wait_finished(job, HZ);
>> +    done = drm_mock_sched_job_wait_finished(job, MOCK_TIMEOUT);
>>       KUNIT_ASSERT_FALSE(test, done);
> 
> Above two are related to timeout handling and should be safe to change.
> 
> With HZ / 5 first assert could have a false negative if timeout work 
> would run, but later than 100ms (HZ / 5 / 2). And the second a false 
> negative if it fails to run in 300ms (HZ / 5 / 2 + HZ / 5). Neither 
> failure sounds likely in the kunit environment so, again, I think those 
> two are okay to speed up.

What do you think about using a slightly bigger timeout? Maybe HZ / 4 or
HZ / 2.

Best Regards,
- Maíra

> 
> Regards,
> 
> Tvrtko
> 
>>       KUNIT_ASSERT_EQ(test,
>>
>