[igt-dev] [PATCH i-g-t] igt/tests: kms_plane_stress: Add plane stress test

[Maarten Lankhorst]

Op 21-03-2019 om 14:59 schreef Peres, Martin:
> On 21/03/2019 15:06, Maarten Lankhorst wrote:
>> Op 21-03-2019 om 13:59 schreef Lisovskiy, Stanislav:
>>> On Thu, 2019-03-21 at 13:41 +0100, Maarten Lankhorst wrote:
>>>> Op 21-03-2019 om 13:34 schreef Stanislav Lisovskiy:
>>>>> This test attempts to utilize all connected
>>>>> outputs at the same time, using maximum possible
>>>>> resolution and amount of planes, to check whether
>>>>> we are hiting any kind of bandwidth, watermark or
>>>>> other limitations.
>>>>>
>>>>> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
>>>>> ---
>>>>>  lib/igt_kms.h            |   7 ++
>>>>>  tests/Makefile.sources   |   1 +
>>>>>  tests/kms_plane_stress.c | 247
>>>>> +++++++++++++++++++++++++++++++++++++++
>>>>>  tests/meson.build        |   1 +
>>>>>  tests/test.png           | Bin 0 -> 1068158 bytes
>>>> Remove the test png? You can use cairo calls to draw something, or
>>>> igt_create_pattern_fb to get a default pattern.
>>> Yes, can remove it. Just wanted some nice image here, however probably
>>> yeah will leave it for local testing.
>>>
>>>> How is this different from kms_atomic_transition btw? It tries the
>>>> same at least.
>>> Well, I guess kms_atomic_transition doesn't utilize all pipe at the
>>> same time, it goes just one by one. Here it tries to use all pipes
>>> at the same time.
>>>
>> But it does have tests for all modes, see run_modeset_transition. Only thing missing is
>>
>> that we don't enable all planes yet. But this should be easy to add with try commit.
> The goal of this test is to be a pathological test case for the
> watermarks, which it has not reached yet. This test needs to enable all
> the pipe and all the planes, then increase the size of the planes until
> try-commit fails. Then we should commit the last-accepted configuration,
> and collect CRCs (check if they are stable) for 5 seconds. This could be
> named igt at kms_watermark@display, and I think we should iterate through a
> short list of formats that have widely different access patterns.
>
> Another subtest would do the same thing as display, but also add a
> thread that runs memcpy continuously. This could be
> igt at kms_watermark@display+cpu.
>
> Another subtest would also spawn a GPU kernel doing blits (this is
> faster than the blitter). This could be igt at kms_watermark@display+render
> and should skip on non-intel platforms.
>
> And finally, we could have a @all subtest that just tries running
> everything in parallel. I think @display and @all should be the only
> ones found in CI.
>
> At all time, the CRCs should not change and no underruns should be
> reported. Any failure is a failure from the kernel to set high-enough
> watermarks.
>
> If you think the right place for this is kms_atomic_transition, then I
> am fine with it.

kms_atomic_transition was meant to hit all kind of limitations, including testing all kind of transitions while all planes are enabled. Could be good for this kind of stuff too.