> 1. surfaceA emits a frame, one is scheduled > 2. surfaceA emits another frame, but still only one is scheduled for > compositing
Isn't schedule_compositing() called with num_frames=2 the second time (I would expect buffers_ready_for_compositor() to return 2 the second time, if the first frame hasn't been rendered)? -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to mir in Ubuntu. https://bugs.launchpad.net/bugs/1379610 Title: [regression] MultiThreadedCompositor fails to schedule sufficient frames and may lag at random times Status in Mir: In Progress Status in Mir 0.7 series: Triaged Status in Mir 0.8 series: Triaged Status in “mir” package in Ubuntu: Triaged Status in “mir” package in Ubuntu RTM: Triaged Bug description: MultiThreadedCompositor fails to schedule sufficient frames in a mostly-idle single surface scenario: 1. surfaceA emits a frame, one is scheduled 2. surfaceA emits another frame, but still only one is scheduled for compositing 3. We composite only one frame (frames_scheduled == 1) 4. System is idle for some unknown time, with no compositing scheduled but surfaceA has its 2nd frame rendered that we're not seeing. The problem is: void schedule_compositing(int num_frames) { std::lock_guard<std::mutex> lock{run_mutex}; if (num_frames > frames_scheduled) { frames_scheduled = num_frames; run_cv.notify_one(); } } If a surface only emits schedule_compositing(1) but does it multiple times per compositor frame, then the second and subsequent frames won't get scheduled. This can happen for surfaces that are triple (or higher) buffered; i.e. any Mir client right now. If correct, this would explain bug 1295851 but I will keep them separate while we're not 100% sure. To manage notifications about this bug go to: https://bugs.launchpad.net/mir/+bug/1379610/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
