[igt-dev] [PATCH i-g-t 1/3] i915/gem_exec_schedule: Check timeslice

[Chris Wilson]

Check that we can run a second request even if an equal priority spinner
is hogging the engine.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 tests/i915/gem_exec_schedule.c | 36 ++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/tests/i915/gem_exec_schedule.c b/tests/i915/gem_exec_schedule.c
index 6e8466299..e57c67170 100644
--- a/tests/i915/gem_exec_schedule.c
+++ b/tests/i915/gem_exec_schedule.c
@@ -1028,6 +1028,39 @@ static void preempt_queue(int fd, unsigned ring, unsigned int flags)
 	}
 }
 
+static void preempt_timeslice(int fd, unsigned ring)
+{
+	const uint32_t bbe = MI_BATCH_BUFFER_END;
+	struct drm_i915_gem_exec_object2 obj = {
+		.handle = gem_create(fd, 4096)
+	};
+	struct drm_i915_gem_execbuffer2 execbuf = {
+		.buffers_ptr = to_user_pointer(&obj),
+		.buffer_count = 1,
+		.flags = ring,
+		.rsvd1 = gem_context_create(fd),
+	};
+	igt_spin_t *spin;
+
+	/*
+	 * Launch a spinner to occupy the target engine, and then
+	 * check we execute a ping underneath it from a second context.
+	 */
+	spin = igt_spin_new(fd, .engine = ring, .flags = IGT_SPIN_POLL_RUN);
+	igt_spin_busywait_until_started(spin);
+
+	/* Both the active spinner and this are at the same priority */
+	gem_write(fd, obj.handle, 0, &bbe, sizeof(bbe));
+	gem_execbuf(fd, &execbuf);
+	gem_sync(fd, obj.handle);
+
+	igt_assert(gem_bo_busy(fd, spin->handle));
+	igt_spin_free(fd, spin);
+
+	gem_context_destroy(fd, execbuf.rsvd1);
+	gem_close(fd, obj.handle);
+}
+
 static void preempt_self(int fd, unsigned ring)
 {
 	uint32_t result = gem_create(fd, 4096);
@@ -1735,6 +1768,9 @@ igt_main
 					igt_subtest_f("preempt-queue-contexts-chain-%s", e->name)
 						preempt_queue(fd, e->exec_id | e->flags, CONTEXTS | CHAIN);
 
+					igt_subtest_f("preempt-timeslice-%s", e->name)
+						preempt_timeslice(fd, e->exec_id | e->flags);
+
 					igt_subtest_group {
 						igt_hang_t hang;
 
-- 
2.23.0.rc1