[igt-dev] [PATCH igt] test/gem_exec_schedule: Check each engine is an independent timeline

[Antonio Argenziano]

On 23/04/18 06:43, Chris Wilson wrote:
> In the existing ABI, each engine operates its own timeline
> (fence.context) and so should execute independently of any other. If we
> install a blocker on all other engines, that should not affect execution
> on the local engine.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

> +static void independent(int fd, unsigned int engine)
> +{
> +	IGT_CORK_HANDLE(cork);
> +	uint32_t scratch, plug, batch;
> +	igt_spin_t *spin = NULL;
> +	unsigned int other;
> +	uint32_t *ptr;
> +
> +	igt_require(engine != 0);
> +
> +	scratch = gem_create(fd, 4096);
> +	plug = igt_cork_plug(&cork, fd);
> +
> +	/* Check that we can submit to engine while all others are blocked */
> +	for_each_physical_engine(fd, other) {
> +		if (other == engine)
> +			continue;
> +
> +		if (spin == NULL) {
> +			spin = __igt_spin_batch_new(fd, 0, other, 0);
> +		} else {
> +			struct drm_i915_gem_exec_object2 obj = {
> +				.handle = spin->handle,
> +			};
> +			struct drm_i915_gem_execbuffer2 eb = {
> +				.buffer_count = 1,
> +				.buffers_ptr = to_user_pointer(&obj),
> +				.flags = other,
> +			};
> +			gem_execbuf(fd, &eb);
> +		}
> +
> +		store_dword(fd, 0, other, scratch, 0, other, plug, 0);
> +	}
> +	igt_require(spin);
> +
> +	/* Same priority, but different timeline (as different engine) */
> +	batch = __store_dword(fd, 0, engine, scratch, 0, engine, plug, 0);

It would be interesting to check that priority scheduling/preemption is 
still happening on the free engine.

> +
> +	unplug_show_queue(fd, &cork, engine);
> +	gem_close(fd, plug);
> +
> +	gem_sync(fd, batch);
> +	gem_close(fd, batch);
> +	igt_assert(gem_bo_busy(fd, spin->handle));
> +
> +	ptr = gem_mmap__gtt(fd, scratch, 4096, PROT_READ);
> +	gem_close(fd, scratch);
> +	igt_assert_eq(ptr[0], engine);
> +
> +	igt_spin_batch_free(fd, spin);
> +	gem_quiescent_gpu(fd);
> +
> +	/* And we expect the others to have overwritten us, order unspecified */
> +	igt_assert_neq(ptr[0], engine);
> +	munmap(ptr, 4096);
> +}
> +
>   static void smoketest(int fd, unsigned ring, unsigned timeout)
>   {
>   	const int ncpus = sysconf(_SC_NPROCESSORS_ONLN);
> @@ -1070,10 +1138,16 @@ igt_main
>   			if (e->exec_id == 0)
>   				continue;
>   
> -			igt_subtest_f("fifo-%s", e->name) {
> -				igt_require(gem_ring_has_physical_engine(fd, e->exec_id | e->flags));
> -				igt_require(gem_can_store_dword(fd, e->exec_id) | e->flags);
> -				fifo(fd, e->exec_id | e->flags);
> +			igt_subtest_group {
> +				igt_fixture {
> +					igt_require(gem_ring_has_physical_engine(fd, e->exec_id | e->flags));

I thought that we added this to the subtests to have a constant list of 
tests for all platforms.

Thanks,
Antonio

> +					igt_require(gem_can_store_dword(fd, e->exec_id) | e->flags);
> +				}
> +
> +				igt_subtest_f("fifo-%s", e->name)
> +					fifo(fd, e->exec_id | e->flags);
> +				igt_subtest_f("independent-%s", e->name)
> +					independent(fd, e->exec_id | e->flags);
>   			}
>   		}
>   	}
>