1. Play a movie, http://roosterteeth.com/archive/?id=1431 for example. 2. Try to use menus or mouse over toolbar buttons. Menus are *very* slow (~30 seconds) to appear/change, and buttons take a *long* time to change on mouse over (~30 seconds). Strangely, the URL bar is reasonably responsive to text input. The video actually looks surprisingly acceptable, as if it is getting painted at a higher rate than chrome content. Scrolling is also very jittery on this site even when the video is paused. (It looks like the Flash might still be painting even when the video is paused, but the browser is responsive when the video is paused.) top shows 65% cpu in plugin-container while video is playing, and 50% cpu in Firefox while video is paused.

Originally reported in bug 579676 comment 24. It would be interesting to see whether bug 556487 helps here.

Is this trunk-only or branch?

It's fallout from Bug 564991, so trunk only. From what I understand, this is from the plugin being rendered to an alpha surface, which is triggered by the fixed background. If I use the Web Developer extension and remove the fixed backgrounds, there's no performance hit (or rendering corruption) when watching the video.

Over to roc per above comments.

Jep confirmed on Windows XP it seems this issue is causing a pretyy heavy Kernel Explosion together with https://bugzilla.mozilla.org/show_bug.cgi?id=595671 on this https://bugzilla.mozilla.org/show_bug.cgi?id=596441 it can cause really pain.

Checked again with my build off 5f2250cb58c9 (pre most of bug 556487 landing): Button mouse-over and scrolling by dragging the scrollbar thumb are now fast and responsive while the video is playing, but menus and scrolling with the mouse wheel or arrow keys are still slow. CPU usage is similar.

Similar behavior with 9d6b04fbec36, which includes the fix for bug 556487. Menus close immediately on click elsewhere; they just take forever to open. That makes me suspect that some (not native X11) events are not getting prioritized correctly wrt painting.

I agree. Content items and browser UI are now responsive. Also, it looks like any lingering Flash rendering artifacts have gone away. The scrolling behavior is handled by Bug 579794 (though it's not much of a tracker with only 1 site listed).

Karl, I'm actually going to reassign this to you :-)

With a build based on 23ac8c47c8c9, which includes the fix for bug 598112, the remaining issues, unresponsive mouse wheel scrolling and menus, are now resolved (on my system, at least). They return when mozilla.plugins.use_layers is set to false, indicating that this was resolved by async plugin painting, just that the code from bug 556487 had no effect until bug 598112 was fixed. CPU usage is still similar.