90695 2012-07-06 10:14:00 -0700 Performance: 2D Canvas rendering spending a lot of CPU time in RenderLayerCompositor::updateLayerCompositingState 2012-07-06 11:08:06 -0700 1 1 1 Unclassified WebKit Canvas 528+ (Nightly build) Unspecified Unspecified RESOLVED FIXED P2 Normal --- 1 junov webkit-unassigned jamesr senorblanco simon.fraser vangelis oldest_to_newest 664167 0 junov 2012-07-06 10:14:00 -0700 While profiling Chrome, executing the benchmark page found here: https://github.com/sibblingz/PerfMarks A hot spot was detected detected in RenderLayerCompositor::updateLayerCompositingState (mostly in updateGraphicsLayerConfiguration()), which appears to be called once for every 2D canvas primitive draw. For some of the sub tests of this benchmark, as much as 20% of CPU time can be spent in that function. Since canvas draws do not impact the layout of composited layers, there should be no need to visit this code so often. Related bug: https://bugs.webkit.org/show_bug.cgi?id=90630 664204 1 junov 2012-07-06 11:08:06 -0700 fixed by r121987: <http://trac.webkit.org/changeset/121987> The call to RenderLayerCompositor::updateLayerCompositingState is now bypassed when contentChanged() is called with CanvasPixelsChanged rather than CanvasChanged.