The set of six patches by prolific AMD open-source driver developer Marek Olšák revolve around improving performance in cases where there is limited video RAM and not enough vRAM for all of the buffers.
With a Radeon HD 5670 graphics card with 512MB of video memory and using the R600 Gallium3D driver, Marek was seeing 51%+ better performance at 1920x1080 for Unigine Heaven and similar wins at the higher resolutions where the game/application was trying to use more than 512MB of video memory.
Besides the six patches today, Marek is also working out some other possible Radeon memory performance improvements dealing with virtual memory support for vRAM and support for uncached GTT. To go with these six Radeon DRM driver patches, Marek will also be posting some Radeon Mesa Gallium3D patches later in the day. These initial patches can be found on the dri-devel list.