On Wed, Mar 30, 2011 at 7:04 AM, Jerome Glisse <j.glisse@xxxxxxxxx> wrote: > On Tue, Mar 29, 2011 at 4:26 PM, Daniel Vetter <daniel@xxxxxxxx> wrote: >> On Tue, Mar 29, 2011 at 03:45:34PM -0400, Jerome Glisse wrote: >>> Short lived & small bo would definitly doesn't work well for this kind >>> of API, it would all be a function of the ioctl cost. But i am not >>> sure the drawback would be that big, intel tested with pread/pwrite >>> and gived up don't remember why. For the vbo case you describe the >>> scheme i was thinking would be : allocate bo and on buffer data call >>> upload to the allocated bo using the bind user page feature that would >>> mean zero extra copy operation. For the fire forget case of vbo, >>> likely somekind of transient buffer would be more appropriate. >> >> Just to clarify: Uploads to linear buffers are all done with pwrite (due >> to an api foobar, it's not so great for 2d/tiled stuff). It's amazing how >> much faster that is: Switching vbo's from mmpa to pwrite has given a few >> percent more fps in openarena in i915g! As long as the chunk you're gonna >> write fits into L1 cache, it's probably a net win. >> -Daniel > > What i had in mind was something little bit more advance that pwrite, > somethings that would take width,height,pitch of userpage and would be > able to perform proper blit. But yes pwrite in intel is kind of > limited. TTM has support for userpage binding we just don't use it. Dave. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
