[Intel-gfx] [RFC i-g-t v3] tests/gem_exec_pad_to_size: Test object padding at execbuf

[Tvrtko Ursulin]

On 04/01/2015 05:39 PM, Chris Wilson wrote:
> On Wed, Apr 01, 2015 at 05:31:16PM +0100, Chris Wilson wrote:
>> On Wed, Apr 01, 2015 at 05:07:25PM +0100, Tvrtko Ursulin wrote:
>>>
>>> On 04/01/2015 04:42 PM, Chris Wilson wrote:
>>>> On Wed, Apr 01, 2015 at 04:14:52PM +0100, Tvrtko Ursulin wrote:
>>>>> +	/* Re-exec with padding set. */
>>>>> +	igt_assert(exec(fd, eb_handles, pad_to_size, offsets) == 0);
>>>>
>>>> The crux of the test is that we generate two objects such that
>>>>
>>>> B_offset = A_offset + A_size
>>>>
>>>> and then tell the kernel that A is actually 2*size (A_pad_to_size)
>>>>
>>>>> +	if (offsets[1] > offsets[0])
>>>>> +		distance = offsets[1] - offsets[0];
>>>>> +	else
>>>>> +		distance = offsets[0] - offsets[1];
>>>>
>>>> The assertion I feel should only be that
>>>>
>>>> B_offset + B_size <= A_offset && B_offset >= A_offset + A_pad_to_size
>>>
>>> I don't get this. B starts after A + padding, but B ends before A?
>>
>> s/&&/||/
>
> Sorry &&. Gah, must be time for a coffee break.
>
> The assertion is that the objects do not overlap based on the pad_to_size we
> expect the kernel to apply, rather than their natural size. If the
> kernel doesn't move the objects, they would it would fail.

You know all this time I didn't realize you were saying me check was 
broken, just that it was confusing. :)

Regards,

Tvrtko