On 24.06.2009 20:17, Jerome Glisse wrote: > I think we should let user ask at gem map ioctl time if userspace wants > an surface backed mapping or not, and gem map will reply with a success > or failure. So if object is in vram and there is a surface reg available > it will succeed, if object is in system ram it will report to userspace > that there is not automatic untiling and that userspace is on its own > to untile the buffer. > > For the X server that the front buffer is mapped first and never > unmapped, it should get a surface (assuming no other process already > stole all the surface). For pixmap i think be better of not using > tiling for time being (or macro tiling only benchmark below). > > Mesa, map/unmap things and should be able to untile on its own for > front/zbuffer (we need to add texture but i am not sure it's worth > it, see benchmark below). I don't see benchmark with texture tiling below... It definitely made some difference though when I implemented (and measured...) this, though I never really worried that much about tiled compressed textures, not sure micro tiled is even possible (and would make sense) but macro tiled certainly should be (but IIRC I tried to measure it and it didn't make much of a difference on r200 but it could have changed with newer chips). That said, don't forget that the performance improvement this gives is chip specific, generally giving more improvement with newer chips. IIRC you definitely don't want to micro tile the front buffer pre-r300.
Roland ------------------------------------------------------------------------------ -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
