On 05/23/2012 11:06 AM, Mikkel Kamstrup Erlandsen wrote: > On 05/23/2012 09:31 AM, Michal Hruby wrote: >> Hey everyone, >> >> as I already discussed with some of you, I was looking into optimizing >> parts of Unity some time ago, with the specific goal of making the dash >> open as fast as possible. >> >> I already opened https://bugs.launchpad.net/nux/+bug/994884 fixing which >> should help with the initial open, but I experimented further and one of >> the things that I tried was to increase priority of UBus message >> processing (IDLE -> DEFAULT), afterwards I measured the time delta >> between LauncherController::SendHomeActivationRequest and >> DashView::DrawContent (ie time between unity getting the Super keypress >> event and it painting the dash), and the results were quite interesting: >> >> Trunk: >> - idle system avg: 126ms >> - system under load avg: 289ms >> >> Increased UBus prio: >> - idle system avg: 103ms >> - system under load avg: 160ms >> >> So a speedup of 20-45%, which is pretty nice for a one liner... That >> said I'm not suggesting that this is a correct fix, but it seems like >> we're not looking at the bigger picture of main loop interactions. For >> example GTK makes sure that geometry changes are always processed with >> higher priority than draws, do we do that? (it would surely help with >> the bug mentioned above). >> >> Thoughts how to improve the situation? Comments? > > One thing we might wanna look at is how many GSources we create. I > read somewhere that someone saved a lot of time changing to having his > callbacks share a single GSource, instead of creating and attaching a > gajillion sources. This is not just for UBus of course, but in > anything perf critical (nux/unity/compiz jumps to mind). >
Yep, I saw that in multiple glib-based apps I was working on - reusing a source makes quite a difference especially on high-res timers (it's quite noticeable even on ones with 40ms timeout). -- Mailing list: https://launchpad.net/~unity-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~unity-dev More help : https://help.launchpad.net/ListHelp
