[Mesa-dev] [PATCH 0/3] GREMEDY_string_marker support

[Ian Romanick]

On 08/17/2015 11:06 AM, Rob Clark wrote:
> On Mon, Aug 17, 2015 at 1:12 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> On 08/10/2015 09:15 AM, Rob Clark wrote:
>>> From: Rob Clark <robclark at freedesktop.org>
>>>
>>> Punch it through mesa and gallium, plus implementation in freedreno to
>>> serve as an example.  Radeon should be able to do a similar thing with
>>> no-op packets.  Not sure about other drivers.
>>
>> The idea behind this extension (and the way the only other
>> implementation of it works) is that the debug tool itself exposes it to
>> the application without the driver knowing.  This allows the developer
>> to set breakpoints on certain messages, etc.
>>
>> Given that usage model, there may be applications that will start
>> calling glStringMarkerGREMEDY as soon as the extension string is there.
>>  After all, you'll on see that in the debugger, so who cares about
>> performance there, right? :(  I think it would be better to not enable
>> the extension by default.  Maybe require a driconf option or debug
>> context or something.
>>
>>> Plan to use this extension from apitrace, to emit call and frame #'s
>>> for draw commands, so I can find the corresponding draw from cmdstream
>>> dump (ie. to debug lockups, incorrect rendering, etc).
>>
>> Clever. :)
>>
>> I think the other way to do this would be to insert a fence with an
>> object label.
>>
>>     GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
>>
>>     glObjectPtrLabel(fence, 0, "call ### frame ###");
> 
> 
> José Fonseca mentioned on apitrace list, when I submitted
> corresponding apitrace patch, KHR_debug..  which already has
> GL_DEBUG_TYPE_MARKER which seems to be intended for this sort of
> usage.
> 
> So I was kinda thinking to respin these patches to add calls to
> Driver.EmitStringMarker() in case of GL_DEBUG_TYPE_MARKER.  (Although
> I was a bit unsure if that should be *in addition to* or *instead of*
> the normal codepaths for glDebugMessageInsert())

I completely missed that when I spent 3 seconds skimming KHR_debug. :)

I think it would have to be in addition to.  I don't know if there are
any conformance tests for this part of KHR_debug, but I could imagine a
test generating a bunch of messages via glDebugMessageInsert and
checking that they show up through the callback.  If an application
doesn't want to see those messages, it can use glDebugMessageControl to
filter them:

    glDebugMessageControl(GL_DONT_CARE,
                          GL_DEBUG_TYPE_MARKER,
                          GL_DONT_CARE,
                          0,     // count
                          NULL,  // message IDs
                          GL_FALSE);

Or... apitrace could do that to specifically filter the messages that it
will generate.

In any case, I like José's suggestion.

> BR,
> -R
> 
> 
>>> Rob Clark (3):
>>>   mesa: add GREMEDY_string_marker
>>>   gallium: add GREMEDY_string_marker
>>>   freedreno: implement emit_string_marker
>>>
>>>  src/gallium/docs/source/screen.rst                |  1 +
>>>  src/gallium/drivers/freedreno/freedreno_context.c | 27 +++++++++++++++++++++++
>>>  src/gallium/drivers/freedreno/freedreno_screen.c  |  1 +
>>>  src/gallium/drivers/i915/i915_screen.c            |  1 +
>>>  src/gallium/drivers/ilo/ilo_screen.c              |  1 +
>>>  src/gallium/drivers/llvmpipe/lp_screen.c          |  1 +
>>>  src/gallium/drivers/nouveau/nv30/nv30_screen.c    |  1 +
>>>  src/gallium/drivers/nouveau/nv50/nv50_screen.c    |  1 +
>>>  src/gallium/drivers/nouveau/nvc0/nvc0_screen.c    |  1 +
>>>  src/gallium/drivers/r300/r300_screen.c            |  1 +
>>>  src/gallium/drivers/r600/r600_pipe.c              |  1 +
>>>  src/gallium/drivers/radeonsi/si_pipe.c            |  1 +
>>>  src/gallium/drivers/softpipe/sp_screen.c          |  1 +
>>>  src/gallium/drivers/svga/svga_screen.c            |  1 +
>>>  src/gallium/drivers/vc4/vc4_screen.c              |  3 ++-
>>>  src/gallium/include/pipe/p_context.h              |  7 ++++++
>>>  src/gallium/include/pipe/p_defines.h              |  1 +
>>>  src/mapi/glapi/gen/GREMEDY_string_marker.xml      | 18 +++++++++++++++
>>>  src/mapi/glapi/gen/Makefile.am                    |  1 +
>>>  src/mapi/glapi/gen/gl_API.xml                     |  2 ++
>>>  src/mesa/main/dd.h                                |  6 +++++
>>>  src/mesa/main/debug.c                             | 14 ++++++++++++
>>>  src/mesa/main/debug.h                             |  3 +++
>>>  src/mesa/main/extensions.c                        |  1 +
>>>  src/mesa/main/mtypes.h                            |  1 +
>>>  src/mesa/state_tracker/st_context.c               |  9 ++++++++
>>>  src/mesa/state_tracker/st_extensions.c            |  1 +
>>>  27 files changed, 106 insertions(+), 1 deletion(-)
>>>  create mode 100644 src/mapi/glapi/gen/GREMEDY_string_marker.xml
>>
>