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

[Tvrtko Ursulin]

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 <mca...@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.

        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.

Regards,

Tvrtko

  
  	KUNIT_ASSERT_EQ(test,