1443299 - Serious jank on reddit (generally)

Status: RESOLVED DUPLICATE of bug 1449033

(Core :: JavaScript: GC, enhancement)

Description

[Kannan Vijayan [:djvj]]

I ran into some serious jank on reddit - pauses for large fractions of a second once every two seconds or so.  Made it impossible to type.  Captured this and the profile shows a lot of GCs.

Profile:

https://perfht.ml/2D24Jsk

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Yeah, some pretty serious GC and CC going on in here. Have you seen this since? I wonder if we're just leaking and there's a ton of stuff on the heap.

Could we see an about:memory report while in this state?

Comment 2

[Kannan Vijayan [:djvj]]

This shows up when the browser has been open for a while, but it doesn't always show up.  It's unpredictable when it shows up, outside of the fact that it's correlated with browsers that have been running for a long time, with lots of tabs.

I did not capture an about:memory for this, but I will the next time it happens.  Keeping needinfo alive so I can find this the next time it happens.

Comment 3

[Paul Bone [:pbone]]

The GC is going a bit over-budget in markWeakReferences (which is somewhat common) but in this example it's going VERY over-budget in markWeakReferences.  I think neither of these can run incrementally yet.   This is a good useful profile, and it'd be very interesting to see about:memory.

Comment 4

[Andrew McCreight [:mccr8]]

Looking at the profile, I think this is a duplicate of bug 1449033. I'm guessing that you have Reddit Enhancement Suite installed (as that was causing problems for people on Reddit). Please reopen if you are still experiencing this.