On this page the lower section of the page constantly blinks/disappears when I scroll with APZ turned on when I'm using my main profile. It looks like I need to have e10s enabled too.

(In reply to avada from comment #0) > It looks like I need to have e10s enabled too. Yeah, APZ is disabled if e10s is disabled. Also, what platform are you seeing this on?

(And also what version/build of FF?)

(In reply to Kartikaya Gupta (email:kats@mozilla.com) from comment #1) > (In reply to avada from comment #0) > > It looks like I need to have e10s enabled too. > > Yeah, APZ is disabled if e10s is disabled. Also, what platform are you > seeing this on? Info added. (In reply to Kartikaya Gupta (email:kats@mozilla.com) from comment #2) > (And also what version/build of FF?) Trunk was already set. I tried yesterday and today.

#1 Regression (hang when scroll) https://hg.mozilla.org/integration/fx-team/pushloghtml?fromchange=cbe91037c39d&tochange=14c8c3fd403c Triggered by: Bug 1156401 #2 Regression (Fixed the hang, but flicker when scroll) https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=1a33c4ca043c&tochange=cc76f739f1cc Triggered by: cc76f739f1cc Kartikaya Gupta — Bug 1161040 - Don't set a scrollparent on the root content document in the child process that points to itself. r=tn

Im having the same issue of elements on pages disappearing while I scroll. I tried with and without HWA. Seems like its appears to happen with HWA on. Webpage - https://www.reddit.com/r/microsoft/comments/3fcf0l/windows_10_is_now_installed_on_67_million_pcs_as/ Firefox Nighlty - 42.0a1 (2015-08-01); Windows 7 Ultimate. Graphics Info:- Adapter Description Intel(R) HD Graphics Family Adapter Description (GPU #2) NVIDIA GeForce GT 525M Adapter Drivers igdumd64 igd10umd64 igd10umd64 igdumdx32 igd10umd32 igd10umd32 Adapter Drivers (GPU #2) nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Adapter RAM Unknown Adapter RAM (GPU #2) 1024 Asynchronous Pan/Zoom wheel input enabled ClearType Parameters Gamma: 2200 Pixel Structure: R ClearType Level: 100 Enhanced Contrast: 50 Device ID 0x0116 Device ID (GPU #2) 0x0df5 Direct2D Enabled true DirectWrite Enabled true (6.2.9200.17292) Driver Date 4-10-2011 Driver Date (GPU #2) 4-8-2015 Driver Version 8.15.10.2361 Driver Version (GPU #2) 9.18.13.5012 GPU #2 Active false GPU Accelerated Windows 1/1 Direct3D 11 (OMTC) Subsys ID 04ca1028 Subsys ID (GPU #2) 04ca1028 Supports Hardware H264 Decoding true Vendor ID 0x8086 Vendor ID (GPU #2) 0x10de WebGL Renderer Google Inc. -- ANGLE (Intel(R) HD Graphics Family Direct3D11 vs_4_1 ps_4_1) windowLayerManagerRemote true AzureCanvasBackend direct2d 1.1 AzureContentBackend direct2d 1.1 AzureFallbackCanvasBackend cairo AzureSkiaAccelerated 0 Also it appears that it affects MacOS users too: https://www.reddit.com/r/firefox/comments/3f9i9b/some_strange_graphic_problems_it_is_firefox/

I didn't see anything unusual on that reddit page and where it links to. Did you try the url for this bug? If you don't experience it there yours is not the same bug.

I can repro the original report (comment 0) and based on paint-flashing I think this is again caused by the checkerboard-background-painting code in the compositor. I'll investigate more.

Truncating the displayport margins during the float->int conversion was causing the displayport to be smaller than expected. If you scrolled near the edge of the page on pages of certain dimensions it would result in the APZ code checkerboarding and drawing a background. This fixes it. Note that I left the "budget" amount as an int; we probably still want to err on the side of a smaller budget. In most cases the displayport margins aren't hitting the budget anyway so it doesn't make a difference.