[Affected versions]: - Firefox 51.0.1 - Firefox 52RC - latest Aurora 53.0a2 - latest Nightly 54.0a1 [Affected platforms]: - Linux 16.04 x64 LTS [Steps to reproduce]: 1. Open http://chandlerprall.github.io/Physijs/examples/jenga.html 2. Click and drag the blocks 3. Observe FPS on top left corner [Expected result]: - Both FPS displayed are high (and have approximately the same rate) and the blocks can be easily moved around [Actual result]: - Bottom FPS rate is very low (~0-10) and there is a delay when moving blocks (or the blocks are not moving at all) [Regression range]: - https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=f5cd6f6bc89e310091674f09f19e18f92a949aa6&tochange=484087507430a3008fdc0d54685e3c3d4b82f948 Although from this range I suspect bug 1288746, mozregression tool points to bug 1300658. [Note]: - Frame rate is low on all versions, although there are some spikes (111-112) on RC to Nightly who aren't improving performance
Adding suspected culprits to See Also section until we know for sure.
So, bug 1300658 works the same across all platforms. On windows 10 I get 60fps on this site in 54.0a1 (2017-03-01) (64-bit). Bug 1300658 will delay some runnables from worker threads if the main thread is busy. This suggests to me that the main thread on your linux machine is saturated for some reason. Is it getting webgl hardware acceleration?
I've hit this without modifying the default profile on two Linux machines. Here's the about:support Graphics section: Graphics Features Compositing Basic Asynchronous Pan/Zoom wheel input enabled; touch input enabled WebGL Renderer Intel Open Source Technology Center -- Mesa DRI Intel(R) Ivybridge Desktop WebGL2 Renderer Intel Open Source Technology Center -- Mesa DRI Intel(R) Ivybridge Desktop Hardware H264 Decoding No Audio Backend pulse GPU #1 Active Yes Description Intel Open Source Technology Center -- Mesa DRI Intel(R) Ivybridge Desktop Vendor ID Intel Open Source Technology Center Device ID Mesa DRI Intel(R) Ivybridge Desktop Driver Version 3.0 Mesa 11.2.0 Diagnostics AzureCanvasAccelerated 0 AzureCanvasBackend skia AzureContentBackend skia AzureFallbackCanvasBackend none CairoUseXRender 0 Decision Log HW_COMPOSITING blocked by default: Acceleration blocked by platform OPENGL_COMPOSITING unavailable by default: Hardware compositing is disabled If I set webgl.force-enabled, webgl.msaa-force and layers.acceleration.force-enabled to true the result is about the same.
Too late for a fix for 53. If this isn't something we care about in time for 54 it may just go into general backlog.