[Intel-gfx] [PATCH i-g-t 3/3] tests/gem_exec_schedule: Add test for resetting preemptive batch

[Antonio Argenziano]

This patch adds a test that will trigger a preemption of a low priority
batch by a 'bad' batch buffer which will hang. The test aims at making
sure that a hanging high priority batch will not disrupt the submission
flow of low priority contexts.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski at intel.com>
Signed-off-by: Antonio Argenziano <antonio.argenziano at intel.com>
---
 tests/gem_exec_schedule.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tests/gem_exec_schedule.c b/tests/gem_exec_schedule.c
index ae44a6c0..5a4d63f9 100644
--- a/tests/gem_exec_schedule.c
+++ b/tests/gem_exec_schedule.c
@@ -511,6 +511,39 @@ static void preempt_self(int fd, unsigned ring)
 	gem_close(fd, result);
 }
 
+static void bad_preemptive(int fd, unsigned ring)
+{
+	igt_spin_t *spin[16];
+	igt_spin_t *bad;
+	uint32_t ctx[2];
+
+	ctx[LO] = gem_context_create(fd);
+	gem_context_set_priority(fd, ctx[LO], MIN_PRIO);
+
+	ctx[HI] = gem_context_create(fd);
+	gem_context_set_priority(fd, ctx[HI], MAX_PRIO);
+
+	for (int n = 0; n < 16; n++) {
+		gem_context_destroy(fd, ctx[LO]);
+		ctx[LO] = gem_context_create(fd);
+		gem_context_set_priority(fd, ctx[LO], MIN_PRIO);
+
+		spin[n] = __igt_spin_batch_new(fd, ctx[LO], ring, 0, true);
+		igt_debug("spin[%d].handle=%d\n", n, spin[n]->handle);
+	}
+
+	bad = igt_spin_batch_new(fd, ctx[HI], ring, 0, false);
+	gem_wait(fd, bad->handle, NULL);
+
+	for (int n = 0; n < 16; n++) {
+		igt_assert(gem_bo_busy(fd, spin[n]->handle));
+		igt_spin_batch_free(fd, spin[n]);
+	}
+
+	gem_context_destroy(fd, ctx[LO]);
+	gem_context_destroy(fd, ctx[HI]);
+}
+
 static void deep(int fd, unsigned ring)
 {
 #define XS 8
@@ -1033,6 +1066,12 @@ igt_main
 						preempt(fd, e->exec_id | e->flags, NEW_CTX | HANG_LP);
 						igt_fork_hang_detector(fd);
 					}
+
+					igt_subtest_f("bad-preemptive-%s", e->name) {
+						igt_stop_hang_detector();
+						bad_preemptive(fd, e->exec_id | e->flags);
+						igt_fork_hang_detector(fd);
+					}
 				}
 
 				igt_subtest_f("deep-%s", e->name)
-- 
2.14.2