Last week the new NVIDIA Linux Beta introduced GLX_EXT_buffer_age support. This GLX extension can be used for fixing tearing problems and the performance of compositing window managers. An experimental Compiz can already make use of GLX_EXT_buffer_age for bettering the window manager's performance.
Kristian Høgsberg has now implemented the EGL_EXT_buffer_age for Mesa. The EGL_EXT_buffer_age extension is equivalent to the GLX version but for EGL instead. EGL is the future over GLX and EGL is used by Wayland, which is where Kristian's concerning himself with this buffer-age support.
The EGL_EXT_buffer_age support comes via a set of eight patches currently on the mesa-dev list. There's some infrastructure plumbing for EGL_EXT_buffer_age, implementing the support within GBM, adding the support to EGL_DRI2, and then to EGL/Wayland.