[Intel-gfx] [PATCH 4/4] igt/gem_stolen: Verify contents of stolen-backed objects across hibernation

[Tvrtko Ursulin]

Hi,

On 02/12/15 09:24, ankitprasad.r.sharma at intel.com wrote:
> From: Ankitprasad Sharma <ankitprasad.r.sharma at intel.com>
>
> This patch verifies if the contents of the stolen backed object were
> preserved across hibernation. This is to validate kernel changes related
> to moving stolen-backed objects to shmem on hibernation.
>
> Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma at intel.com>

Please Cc me if it is expected I keep reviewing this.

> ---
>   tests/gem_stolen.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 86 insertions(+)
>
> diff --git a/tests/gem_stolen.c b/tests/gem_stolen.c
> index 3374716..1f13fb0 100644
> --- a/tests/gem_stolen.c
> +++ b/tests/gem_stolen.c
> @@ -290,6 +290,89 @@ static void stolen_fill_purge_test(int fd)
>   		gem_close(fd, handle[i]);
>   }
>
> +static void stolen_hibernate(int fd)
> +{
> +	drm_intel_bo *bo;
> +	drm_intel_bo *src, *dest;
> +	int obj_count = 0, i = 0;
> +	int _ret = 0, j = 0;

Don't need to init _ret and j.

> +	uint32_t handle[MAX_OBJECTS], src_handle;
> +	uint32_t *virt;
> +
> +	gem_require_stolen_support(fd);
> +
> +	src_handle = gem_create(fd, SIZE);
> +	igt_assert(!src_handle);

gem_create already asserts this, but isn't it also reversed? Does it run 
and work?

> +	src = gem_handle_to_libdrm_bo(bufmgr, fd,
> +				     "bo", src_handle);
> +	igt_assert(src != NULL);
> +
> +	_ret = drm_intel_gem_bo_map_gtt(src);
> +	igt_assert(!_ret);

I think igt_assert_eq(ret, 0) is a preferred way nowadays.

Also a question, what is the special significance of _ret vs just normal 
ret in this test?

> +
> +	virt = src->virtual;
> +	for (j = 0; j < SIZE/DWORD_SIZE; j++)
> +		virt[j] = DATA;

memset?

> +
> +	drm_intel_bo_unmap(src);
> +	/* Exhaust Stolen space */
> +	do {
> +		handle[i] = __gem_create_stolen(fd, SIZE);
> +		if (handle[i] != 0) {

Maybe it would be more readable and with less indentation:

for (i = 0; i < MAX_OBJECTS; i++) {
	handle[i] = __gem_create_stolen(...);
	if (!handle[i])
		break;

	...

	obj_count++;
}

> +			bo = gem_handle_to_libdrm_bo(bufmgr, fd,
> +						     "verify_bo", handle[i]);
> +			igt_assert(bo != NULL);
> +			_ret = drm_intel_gem_bo_map_gtt(bo);
> +			igt_assert(!_ret);
> +
> +			virt = bo->virtual;
> +			for (j = 0; j < SIZE/DWORD_SIZE; j++)
> +				igt_assert(!virt[j]);

Again, people will probably want igt_assert_eq.

> +
> +			drm_intel_bo_unmap(bo);
> +			drm_intel_bo_unreference(bo);
> +
> +			obj_count++;
> +		}
> +
> +		i++;
> +	} while (handle[i-1] && i < MAX_OBJECTS);
> +
> +	igt_assert(obj_count > 0);
> +
> +	for (i = 0; i < obj_count; i++) {
> +		dest = gem_handle_to_libdrm_bo(bufmgr, fd,
> +					       "dst_bo", handle[i]);
> +		igt_assert(dest != NULL);
> +		intel_copy_bo(batch, dest, src, SIZE);
> +		drm_intel_bo_unreference(dest);
> +	}

Probably worth doing a verification step after each blit. So after 
resume is not the first time you are checking it.

> +	drm_intel_bo_unreference(src);
> +
> +	igt_system_hibernate_autoresume();
> +	/* Check if the object's memory contents are intact
> +	 * across hibernation.
> +	 */
> +	for (i = 0; i < obj_count; i++) {
> +		bo = gem_handle_to_libdrm_bo(bufmgr, fd,
> +					     "verify_bo", handle[i]);
> +		igt_assert(bo != NULL);
> +		_ret = drm_intel_gem_bo_map_gtt(bo);
> +		igt_assert(!_ret);
> +		virt = bo->virtual;
> +		for (j = 0; j < SIZE/DWORD_SIZE; j++)
> +			igt_assert_eq(virt[j], DATA);
> +
> +		drm_intel_bo_unmap(bo);
> +		drm_intel_bo_unreference(bo);
> +	}

Would it be interesting to fill the bos with some more elaborate pattern 
to potentially catch more potential corruption types?

Perhaps incrementing dwords would simply do?

> +	gem_close(fd, src_handle);
> +	for (i = 0; i < obj_count; i++)
> +		gem_close(fd, handle[i]);
> +}
> +
>   static void
>   stolen_no_mmap(int fd)
>   {
> @@ -353,6 +436,9 @@ igt_main
>   	igt_subtest("stolen-fill-purge")
>   		stolen_fill_purge_test(fd);
>
> +	igt_subtest("stolen-hibernate")
> +		stolen_hibernate(fd);
> +
>   	igt_fixture {
>   		intel_batchbuffer_free(batch);
>   		drm_intel_bufmgr_destroy(bufmgr);
>

Regards,

Tvrtko