On Fri, Feb 7, 2014 at 3:55 AM, Michel Dänzer <mic...@daenzer.net> wrote: > On Mon, 2014-02-03 at 18:07 +0100, Marek Olšák wrote: >> Do you mean something like: >> >> write_domains = VRAM >> read_domains = VRAM | GTT >> >> I don't think it's perfect. > > That's what I meant, and of course it's not perfect. :) > > >> We should treat rendering by an app and blitting by u_blitter (= >> texture transfers) differently. We don't want u_blitter to mess up our >> idea about which textures are used as a framebuffer, because once >> u_blitter comes into play, everything can be a framebuffer. >> >> I've got the following idea: >> >> 1) Set the domain to VRAM | GTT by default for all buffers and textures. >> 2) In set_framebuffer_state, if u_blitter isn't blitting, do this to >> the domains of all renderbuffers: if (domains & VRAM) domains &= ~GTT; > > Interesting idea. > > >> That said, I'm not too excited about this. Allowing more stuff to be >> moved to GTT will have an adverse effect on performance. Being more >> aggressive and trying to put more stuff in VRAM should almost always >> be better if you can avoid buffer ping-ponging. > > The above should avoid BO ping pong in some cases, but it may indeed > also cause some BOs to stay in GTT when it would be better for them to > be in VRAM. > > >> I have been messing with the domains since ever and what we have now >> seems to work best. It's not perfect, but I have already tried all the >> other options and they weren't better. > > What metrics did you use to determine that?
Just some tests. For example, Reaction Quake frame rate increased 4 times by changing relocations from VRAM|GTT to VRAM. It also caused buffer ping-ponging for other apps. I guess I'll try my idea described above. Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
