On Wed, 2007-03-21 at 00:58 +0300, malc wrote: > On Tue, 20 Mar 2007, Michel D?nzer wrote: > > > On Thu, 2007-03-15 at 21:36 +0300, malc wrote: > >> > >> Apparently the problem is that pages obtained by the call to > >> get_user_pages admit caching, so adding flush_dcache_range upon > >> dequeuing buffer in the device driver removes the artifacts. > >> > >> Even with this i still get roughly a 3x speedup compared to > >> grab to some buffer then copy to gart with memcpy. > >> > >> However i believe things can be improved: > >> 1. call glXGetMemoryOffsetMESA > >> 2. tell the driver to grab into "special" memory with this offset > >> > >> This should avoid the need of having to mess with get_user_pages and > >> caching altogether. > >> > >> Question is though, is this possible at all? > > > > Possibly. In fact, it should be easy with a traditional AGP bridge which > > provides a physically linear view of the aperture to the CPU. > > Unfortunately, that's not the case with Apple UniNorth bridges, so is > > this on a Mac or a different PowerPC machine such as a Pegasos? If the > > former I suspect you may have to hook into the DRM or agpgart to get at > > the pages backing the AGP mapping. > > Thanks for the answer, i had a feeling of being either completely offtopic > or a subject to overzelous spam filtering. > > It's a Mac (mini) with UniNorth. I don't mind at all having to deal with > non linear mappings, current code is already in this situation.
So I think basically you need to determine the mapping of the allocated memory to physical pages and tell the grabber to write to those pages. > Unfortunately my knowlege of AGP/GARTs/appertures is virtually non-existent, > i was wondering if there's a document that describes the basic concepts to > the layman? I don't know of one, but someone on the list might. -- Earthling Michel Dänzer | http://tungstengraphics.com Libre software enthusiast | Debian, X and DRI developer ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
