On Wed, Dec 18, 2013 at 10:01 AM, Daniel van Vugt <daniel.van.v...@canonical.com> wrote: > The issue is in your response: "almost immediately" :) > > At present, "almost immediately" means waiting for a round trip. Whereas we > can do better than that in theory, by pushing free buffers to the client as > soon as they're available. >
Fair, but I would like to see numbers on the roundtrip penalty you are suspecting here, first :) Cheers, Thomas > > > On 18/12/13 16:58, Thomas Voß wrote: >> >> On Wed, Dec 18, 2013 at 9:43 AM, Daniel van Vugt >> <daniel.van.v...@canonical.com> wrote: >>> >>> At first glance, comparing frame rates between direct (single) and nested >>> (double) server configurations reveals nothing unexpected... >>> >>> Full screen >>> Direct (bypass) 2600 >>> Direct (bypass off) 2400 >>> Nested (bypass) 2450 >>> Nested (bypass off) 2330 >>> >>> But for surfaces which can't be bypassed, something strange happens; >>> nesting >>> is faster! >>> >>> Windowed >>> Nested 4890 >>> Direct 4400 >>> >>> My best theory right now is that we're crippling Mir in the single server >>> case due to: >>> https://bugs.launchpad.net/mir/+bug/1253868 >>> and nesting provides a workaround for that problem by supplying extra >>> levels >>> of buffering. >> >> >> Not sure I'm following your reasoning here: The bug states exactly the >> opposite, i.e., additional buffering wouldn't help. >> In addition: I do not see how a steady-state update scheme on the >> client-side is a problem here. If there are more than two buffers >> available per surface, the client almost immediately receives a new >> buffer when it calls next_buffer. Sure, there is always only one >> buffer in flight, but I cannot see why this would lead to the numbers >> you are reporting here. >> >> Cheers, >> >> Thomas >> >>> >>> Can anyone else think why nested would sometimes be faster than not >>> nested? >>> >>> - Daniel >>> >>> -- >>> Mir-devel mailing list >>> Mir-devel@lists.ubuntu.com >>> Modify settings or unsubscribe at: >>> https://lists.ubuntu.com/mailman/listinfo/mir-devel -- Mir-devel mailing list Mir-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/mir-devel
