[Intel-gfx] [RFC i-g-t v2] tests/gem_exec_pad_to_size: Test object padding at execbuf

[Tvrtko Ursulin]

On 04/01/2015 02:06 PM, Chris Wilson wrote:
> On Wed, Apr 01, 2015 at 12:21:14PM +0100, Tvrtko Ursulin wrote:
>> +	if (drmIoctl(fd, DRM_IOCTL_I915_GEM_EXECBUFFER2, &execbuf))
>> +			ret = -errno;
>
>> +	if (ret == 0) {
>> +		gem_sync(fd, handles[0]);
> Not required for this test. However... You probably want to do the
> gem_sync() first. (Yes, there is an amusing reason to do :)

What reason is that and what do you mean by "first"?

>> +	for (try = 0, idx = 0; try < max_tries;) {
>> +		eb_handles[0] = handles[0];
>> +		eb_handles[1] = loc_handles[idx];
>> +		eb_handles[2] = loc_handles[idx + 1];
>> +
>> +		igt_assert(exec(fd, eb_handles, (uint32_t[2]){0, 0},
>> +				offsets) == 0);
>> +
>> +		if (offsets[1] > offsets[0]) {
>> +			distance = offsets[1] - offsets[0];
>> +			if (distance == PAGE_SIZE)
>> +				neighbours = true;
>> +			pad_to_size[0] = ALIGN(distance + PAGE_SIZE, PAGE_SIZE);
>> +		} else {
>> +			distance = offsets[0] - offsets[1];
>> +			if (distance == PAGE_SIZE)
>> +				neighbours = true;
>> +			pad_to_size[1] = ALIGN(distance + PAGE_SIZE, PAGE_SIZE);
>> +		}
>> +
>> +		if (neighbours)
>> +			break;
>> +
>> +		try++;
>> +		idx +=2;
>
> Just use idx++ here and allocate a new handle one at a time. Just as
> likely to be adjacent to the previous handle as the next one will be to

Ah yes, didn't think of that!

> us. For extra paranoia, you could even try an evict-everything pass :)

You mean if the lightweight approach fails? Ok.

Regards,

Tvrtko