[Mesa-dev] mesa-dev at lists.freedesktop.org

[Kenneth Graunke]

On Friday, March 11, 2011 03:23:47 AM Neeraj N T wrote:
> Hi All,
> I was traversing through the source code of Mesa 7.7 .

Mesa 7.7 is really old at this point...since then, the GLSL compiler was 
entirely rewritten, as was the Intel driver's fragment shader backend.  You 
really want 7.10.1.

> I wanted to write
> an OpenGL application which could measure the graphics performance of my
> board(running on intel i5 with GMA-HD). Is there a flag available which
> can ensure that gpu is acting so that I can capture something like start
> of a frame  from the function "copy_back_to_front"(which I guess is
> called each time something is displayed on screen) ?

In normal, double-buffered rendering, you display the front buffer, render the 
next frame to the backbuffer, and when done, call SwapBuffers to switch the two 
- causing your new frame to appear on the screen.   It sounds like you want to 
take some measurements between successive calls to SwapBuffers.  This should be 
doable.

However, I wonder if what you really want is just intel-gpu-top, available 
from the intel-gpu-tools repository:
http://cgit.freedesktop.org/xorg/app/intel-gpu-tools/

Eric wrote a nice article about how to do initial performance analysis:
http://dri.freedesktop.org/wiki/IntelPerformanceTuning

Hope this helps,
--Kenneth

> Thanks in advance,
> 
> Neeraj N.T