[webkit-dev] Chromium "GPU" LayoutTests

[Adam Barth]

On Mon, Aug 22, 2011 at 3:02 PM, James Robinson <jamesr at google.com> wrote:
> On Mon, Aug 22, 2011 at 2:55 PM, Adam Barth <abarth at webkit.org> wrote:
>> I've been trying to wrap my mind around the "GPU" LayoutTests that
>> Chromium runs.  In
>> <http://trac.webkit.org/browser/trunk/LayoutTests/platform>, there are
>> the following directories:
>>
>> chromium-gpu
>> chromium-gpu-cg-mac
>> chromium-gpu-linux
>> chromium-gpu-win
>>
>> These seem to be related to the webkit_gpu_tests step on these bots:
>>
>> http://build.chromium.org/p/chromium.webkit/builders/Webkit%20Mac10.5%20%28CG%29
>>
>> http://build.chromium.org/p/chromium.webkit/builders/Webkit%20Mac10.6%20%28CG%29
>> http://build.chromium.org/p/chromium.webkit/builders/Webkit%20Linux
>> http://build.chromium.org/p/chromium.webkit/builders/Webkit%20Vista
>> http://build.chromium.org/p/chromium.webkit/builders/Webkit%20Win7
>>
>> This file
>> <http://trac.webkit.org/browser/trunk/Tools/Scripts/webkitpy/layout_tests/port/builders.py>
>> also lists the following bots:
>>
>> Webkit Win - GPU
>> Webkit Win7 - GPU
>> Webkit Linux - GPU
>> Webkit Linux 32 - GPU
>> Webkit Mac10.5 (CG) - GPU
>> Webkit Mac10.6 (CG) - GPU
>>
>> Questions:
>>
>> 1) Do these "- GPU" bots exist anywhere?  (I can't find them, and a
>> recent bug comment indicates that they might be fictional.)
>
> The " - GPU" bots are the same bots as the normal layout test bots, but run
> as a separate step.
>  See http://build.chromium.org/p/chromium.webkit/builders/Webkit%20Mac10.6%20%28CG%29/builds/185,
> for example.  The "bot name" for the GPU tests is the normal bot name with "
> - GPU" appended.
>
>>
>> 2) Are there any other bots related to the GPU configuration other
>> than those listed above?  (For example, is there any coverage of this
>> configuration on build.webkit.org?)
>
> build.webkit.org seems to not be running these tests, for reasons that are
> unclear to me, but they run on the other chromium bots that run layout
> tests.
>
>> 3) Why is webkit_gpu_tests a separate step from webkit_tests?
>
> Different flags are passed to DumpRenderTree, but it runs some of the same
> tests.  This is so we can get coverage for (for instance) the 2d canvas API
> in our hardware and software paths.

Could we instead use the layoutTestController to enable or disable
whatever flags at test-time rather than on the command line?  For
example, we could put the guts of the 2d canvas tests into a
JavaScript file and include it in two HTML files, one that sets the
flag and one that does not.  That's how we handle strict vs quirks
mode, for example.

>> As far as I can tell, other ports, such as Apple-Mac, make use of the
>> GPU but don't impose as large a complexity tax on the project.  Is
>> there something different about Chromium's GPU support that requires
>> this additional complexity?
>
> Other ports have less test coverage, and they don't run the pixel tests at
> all on the bots.

Adam