drm/sched: Fix a race in DRM_GPU_SCHED_STAT_NO_HANG test

The "skip reset" test waits for the timeout handler to run for the duration of 2 * MOCK_TIMEOUT, and because the mock scheduler opted to remove the "skip reset" flag once it fires, this gives opportunity for the timeout handler to run twice. Second time the job will be removed from the mock scheduler job list and the drm_mock_sched_advance() call in the test will fail. Fix it by making the "don't reset" flag persist for the lifetime of the job and add a new flag to verify that the code path had executed as expected.

Tvrtko Ursulin committed 1 year ago

Commit 2650bc41 parent 28c5c483 files · +7 −6Browse files

Unified · Split

3 files

drivers/gpu/drm/scheduler/tests/mock_scheduler.c +1 −1
drivers/gpu/drm/scheduler/tests/sched_tests.h +4 −3
drivers/gpu/drm/scheduler/tests/tests_basic.c +2 −2

drivers/gpu/drm/scheduler/tests/mock_scheduler.c+1−1

@@ -219,7 +219,7 @@ mock_sched_timedout_job(struct drm_sched_job *sched_job) · 218 unmodified lines
219	unsigned long flags;	219	unsigned long flags;
220		220
221	if (job->flags & DRM_MOCK_SCHED_JOB_DONT_RESET) {	221	if (job->flags & DRM_MOCK_SCHED_JOB_DONT_RESET) {
222	job->flags &= ~DRM_MOCK_SCHED_JOB_DONT_RESET;	222	job->flags \|= DRM_MOCK_SCHED_JOB_RESET_SKIPPED;
223	return DRM_GPU_SCHED_STAT_NO_HANG;	223	return DRM_GPU_SCHED_STAT_NO_HANG;
224	}	224	}
225		225

drivers/gpu/drm/scheduler/tests/sched_tests.h+4−3

@@ -95,9 +95,10 @@ struct drm_mock_sched_job { · 94 unmodified lines
95		95
96	struct completion done;	96	struct completion done;
97		97
98	#define DRM_MOCK_SCHED_JOB_DONE 0x1	98	#define DRM_MOCK_SCHED_JOB_DONE 0x1
99	#define DRM_MOCK_SCHED_JOB_TIMEDOUT 0x2	99	#define DRM_MOCK_SCHED_JOB_TIMEDOUT 0x2
100	#define DRM_MOCK_SCHED_JOB_DONT_RESET 0x4	100	#define DRM_MOCK_SCHED_JOB_DONT_RESET 0x4
		101	#define DRM_MOCK_SCHED_JOB_RESET_SKIPPED 0x8
101	unsigned long flags;	102	unsigned long flags;
102		103
103	struct list_head link;	104	struct list_head link;

drivers/gpu/drm/scheduler/tests/tests_basic.c+2−2

@@ -317,8 +317,8 @@ static void drm_sched_skip_reset(struct kunit *test) · 316 unmodified lines
317	KUNIT_ASSERT_FALSE(test, done);	317	KUNIT_ASSERT_FALSE(test, done);
318		318
319	KUNIT_ASSERT_EQ(test,	319	KUNIT_ASSERT_EQ(test,
320	job->flags & DRM_MOCK_SCHED_JOB_DONT_RESET,	320	job->flags & DRM_MOCK_SCHED_JOB_RESET_SKIPPED,
321	0);	321	DRM_MOCK_SCHED_JOB_RESET_SKIPPED);
322		322
323	i = drm_mock_sched_advance(sched, 1);	323	i = drm_mock_sched_advance(sched, 1);
324	KUNIT_ASSERT_EQ(test, i, 1);	324	KUNIT_ASSERT_EQ(test, i, 1);