User Agent: Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:49.0) Gecko/20100101 Firefox/49.0 Build ID: 20160919213653 Steps to reproduce: I was writing a tutorial on using WebGL with ClojureScript and one of the intermediate steps the program goes through manages to crash Firefox. You can retrieve the code in this state by running: $ git clone -b implementation https://github.com/Rovanion/webgl-clojurescript-tutorial.git $ git checkout ce45ebcf6e789da09243039b9498b635b5394130 $ cd webgl-clojurescript-tutorial $ lein figwheel Once figwheel is started and the page loads in your firefox you'll notice how the memory usage of Firefox starts to fluctuate wildly. After about five minutes, on my machine, Firefox will finally crash. I'm running Firefox 49 on 32-bit Ubuntu 16.04 on an Intel i7-2640M with an integrated 2nd generation accelerated Intel graphics controller. As an aside: this behaviour is not seen in Chromium. Actual results: Crashreport: https://crash-stats.mozilla.com/report/index/5fd735a8-ec67-4b05-b7ff-d9bc82160926 Expected results: No crash.

I have tested this on Ubuntu 14.04 32-bits with Firefox 49.0.1 and it is reproducible. The memory usage oscillates and also has high CPU usage. But the browser did not crash even after several minutes use. Here is screen capture: https://testing-1.tinytake.com/sf/MTAwNjk0Ml80MTU3MTky

Make sure that you check out the specificed commit ce45ebcf6e789da09243039b9498b635b5394130. The application behaves much worse on that specific commit. You'll know when you're on it if the clear-color is animating between black and red. The crash could come sooner or later based on how much VRAM or RAM you've got available based on the fact that Firefox crashes in a malloc. My laptop is quite limited in those regards, 4GB RAM and maybe 384MB VRAM (wild guess).

Hey Rovanio, I checked out the commit this time. Thanks for commenting. The browser becomes unresponsive but I do not get any crashes even at this time. I have attached the memory report. Here is the screen capture: https://testing-1.tinytake.com/sf/MTAwNzA0Nl80MTU3Njk3

A web server with the compiled code can be found at: http://rovanion.se/webgl-clojurescript-tutorial/resources/public/

STR: #1 - Load http://rovanion.se/webgl-clojurescript-tutorial/resources/public/ #2 - Watch memory and CPU usage spike

To clearify: What this program does is to rapidly compile and upload tons of shaders to the GPU, one per frame in fact.

The memory report includes: 639.73 MB (91.10%) ── heap-unclassified This doesn't seem likely to be JS related.

We think this is the same as bug 1319426.