On 5/18/14, 2:23 PM, Gavin Sharp wrote:
OMTC is important, and I'm excited to see it land on Windows, but the Firefox and Performance teams have just come off a months-long effort to make significant wins in TART, and the thought of taking a 20% regression (huge compared to some of the improvements we fought for) is pretty disheartening.
My question here is whether we have data that indicates why there is a regression. Are we painting more, or are we waiting on things more?
In particular, if I understand correctly TART uses a somewhat bizarre configuration: it tries to run refresh drivers at 10,000 frames per second (yes, 10kHz). That may not going interact at all well with compositing at 60Hz, and I'm not even sure how well it'll interact with the work to trigger the refresh driver off vsync.
In any case, it's entirely possible to get regressions on TART that have nothing to do with actual slowdowns at normal frame rates. That may not be the case here, but it's a distinct possibility that it is. For example, on Mac we ended up special-casing the TART configuration and doing non-blocking buffer swaps in it (see bug 888899) precisely because otherwise TART ended up gated on things other than actual rendering time. I would not be terribly surprised if something like that needs to be done on Windows too...
-Boris _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
