(In reply to Michel Dänzer from comment #75) > (In reply to Clemens Eisserer from comment #73) > > just to be curious, does it actually map the buffer with the READ flag? > > According to Timothee and the apitrace it does, so > https://patchwork.freedesktop.org/patch/138047/ should help for this issue. it helps, but fps drops quite a bit on my aged r660g gpu (patch applied to mesa 13.0.4). It runs better as Mareks test did before, so maybe it works out for newer hardware.