Network Cache Horrors
Last week we discovered that our cache uses main thread locks to successfully block on off-main thread io. See (Bug 695399, Bug 717761). QA did an experiment which confirmed that our disk cache is performing poorly.
Flash Lag
We are looking into reports of flash lag, tracking Bug 720000. Initial QA data shows a significant slowdown when page is first loaded and smaller slowdowns later. There are also long browser pauses when the flash container progress freezes.
Profiling
Vlad continued work on non-destructive chromehang, Bug 712109. Client-side is ready to land and he is wrapping up symbolification for the server-side.
Interactivity profiler is now able to collect stacks on 64-bit MacOS. Benoit is looking for contributors to add Windows, Linux support (Bug 719536). I highly encourage adventurous contributors to help out with that as it involves modifying some concise, straightforward, yet highly ironic JavaScript. We are also looking for help with the profiler UI. If you are a skilled addon/frontend person, see Bug 719530.
Jeff posted an early preview of about:jank addon. He also working on measuring painting speed via telemetry. Note this addon is buggy and requires a very recent nightly.
Last week I asked for some laggy session restore profiles. I’m behind on reproducing those(will be done today or next week). I’ve been in email contact with several of the commenters. I really appreciate the data gathered so far.
Snappy UX
Jared landed smooth scrolling, Bug 198964. He is now working on hooking it up to scrolling via scrollbar, Bug 710373. Up next: fixing fallout from turning on smooth scrolling, hooking it up to the refresh driver and tweaking scrolling physics.
Marco landed inline autocomplete, Bug 566489 and is now fixing fallout from that too.