The latest Intel Mesa DRI driver addition after landing Broadwell OpenGL 3.3 support earlier in the day is supporting the GL_AMD_performance_monitor extension for "Gen5" Ironlake graphics hardware and newer.
The OpenGL.org registry specification reads on AMD_performance_monitor, "This extension enables the capture and reporting of performance monitors. Performance monitors contain groups of counters which hold arbitrary counted data. Typically, the counters hold information on performance-related counters in the underlying hardware. The extension is general enough to allow the implementation to choose which counters to expose and pick the data type and range of the counters. The extension also allows counting to start and end on arbitrary boundaries during rendering."
This support arriving in Mesa Git master today comes after Intel said back in April they were interested in supporting AMD's performance monitor extension and now complements Mesa's support for GL_ARB_debug_output and the crowd-funded GL_KHR_debug.
The AMD_performance_monitor work for Intel's open-source driver landed with this Git commit and other code activity this morning for working out the plumbing to properly support the OpenGL extension with useful information.