That's not true. PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE does not copy data in radeon drivers. It really does what st/mesa does - it creates a new buffer and throws away the old one, which doesn't take any GPU bandwidth. Doing that at a lower level should be faster in theory (+ drivers have multiple options how to implement the discarding).
Only PIPE_TRANSFER_DISCARD_RANGE copies data in radeon drivers, which is not used here. Marek On Wed, Apr 17, 2013 at 8:15 PM, Eric Anholt <e...@anholt.net> wrote: > Marek Olšák <mar...@gmail.com> writes: > >> The next patch makes sure _NEW_BUFFER_OBJECT is not needlessly set >> for this code. > > This seems like a pretty dubious optimization -- on UMA systems you're > increasing the memory bandwidth usage in the "&& data" case, and only > trying to eliminate update_array_object_max_element, which also happens > with _NEW_PROGRAM (I bet it's true every time that a _NEW_BUFFER_OBJECT > was flagged, anyway). > > In short, for the Mesa core change, I'd like to see some actual > performance justification on this one. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
