Graphics

In some cases Direct2D-accelerated drawing is slower than the non-accelerated path. Jeff Muizelaar fixed a severe gradient ‘hang’ in bug 823147.

Avi Halachmi diagnosed a significant menu performance issue in bug 832641, this was promptly fixed by Matt Woodrow.

Misc Pauses

Vladan Djeric blogged about top main-thread SQL issues contributed by addons. Vladan also produced a chromehang report for last 2 months.

Ehsan Akhgari fixed a chromehang caused by leftover debug code: bug 830765.

Justin Lebar fixed an issue where telemetry memory reporting code was accidentally triggering expensive ‘release memory to OS’ operations: bug 789975.

Shutdown

Sometimes Firefox takes a long time to shutdown. We also have a timer that regularly triggers cycle collection. Olli Pettay disabled this timer during shutdown in bug 822849.