Noticed high CPU and memory use with Fission enabled. Hoping there is something interesting in the profile and memory report.

Profile: https://share.firefox.dev/2H6beCw

Asif, how are you identifying the high CPU and memory use? Windows Task Manager? Did this particular problem happen just once or multiple times?

kmag looked at the memory profile. There are a bunch of content processes, but they're all under ~500 MB which is not bad. But the profiler's memory graph shows one process's memory usage (for an ad iframe, probably loading new ads) increasing steadily, which is worrying.

Perhaps this another problem related to the Reddit Enhancement Suite extension. I reported a RES bug about its memory usage and they fixed a memory issue.

Windows Task Manager and things get very slow and respond slowly - I see it slowing down, then I check the task manager. Just this once - I probably should have waited for it to happen more often, but I update Nightlies when they are available, so memory issues are harder to hit - I figured I would report it when I see them.

It may be RES, I had actually thought the the snudown issue was fixed, but it looks like it hasn't yet been released. If you don't see anything, feel free to close.

Kim, can someone from perf team look at the profile to find the issue here?

The profile in comment 0 unfortunately doesn't show anything interesting. There's about 14% activity on the main thread of one of the content processes, but the rest looks idle.
We still don't have good tooling to track down CPU usage issues.

Asif, can you get a profile of user interactions that seem slow?

kmag looked at the memory report. He says the extension process has a lot of StructuredCloneHolder objects (88,000+) and many 16 KB JSON strings. Are these leaks in the extension process?

Nika thinks this problem is probably not caused by Fission.

If you can find something in the extension process, an investigation would be great, but if not, I am happy to open a new bug if I see something new.

There's no activity in the extension process in that profile, except for some very short blips of cycle collection.