1445422 - live maps at weather.com are slow (with profile)

Status: NEW

(Core :: CSS Parsing and Computation, defect, P3)

Description

[Asa Dotzler [:asa]]

A user reported extremely slow live maps at weather.com on Firefox 58 and 59. He's got a powerful system (win 10 with an AMD Threadripper 1950x and 64gb of ddr4 3200 driving a 4K display) and this is his profile. https://t.co/ExkAi5nPVF for https://weather.com/weather/radar/interactive/l/USOH1375:1:US?layer=radar&overlays=currtrafficspeed

Comment 1

[Emma Humphries ☕️🎸🧞‍♀️✨ (she/they) [:emceeaich] (Pacific Time) use needinfo]

:mconley, thank you!

Comment 2

[Mike Conley (:mconley) (:⚙️)]

There are a few things going wrong here at first glance, but the big one appears to involve Stylo / Rayon:

https://perfht.ml/2r25HBM

Content Process 5 (which is hosting at least one weather.com tab) is going absolutely bonkers. Hey emilio, got any insight?

Comment 3

[Emilio Cobos Álvarez [:emilio]]

So, my profile of that page looks fairly different, fwiw, mostly spent in JS.

  https://perf-html.io/from-addon/calltree/?range=19.5583_21.8275&thread=2&threadOrder=0-2-1&v=3

That machine has 16 physical CPUs, which means that we probably choose too many threads for the thread-pool. It's kinda fishy that in that profile there are no restyle markers, but the profile is 1 month old.

Seeing what's going on in the StyleThreads would be useful, but I suspect it's just Rayon scaling not-so-well, and the threads starving and consuming CPU.

Bobby, we had a bug on file for Bas's machine (can't find it). Should we just clamp the number of style threads?

Comment 4

[Bobby Holley (:bholley)]

That discussion was bug 1431285 comment 13. Still on my todo list, but haven't gotten to it, and likely won't get to it before heading out on PTO.

I do think we should probably clamp, but I'd like us to measure per the aforementioned comment.

I'd also like to understand that user's profile better. Could we get her/him to add StyleThread to the list of profiled threads?

Comment 5

[Emilio Cobos Álvarez [:emilio]]

Asa, any chance? Thanks!

Comment 6

[Asa Dotzler [:asa]]

(In reply to Emilio Cobos Álvarez [:emilio] (Away-ish from 27/04 to 09/05) from comment #5)
> Asa, any chance? Thanks!

I'm sorry. I lost track of the reporter. I'll try to find him.

Comment 7

[Asa Dotzler [:asa]]

(In reply to Asa Dotzler [:asa] from comment #6)
> (In reply to Emilio Cobos Álvarez [:emilio] (Away-ish from 27/04 to 09/05)
> from comment #5)
> > Asa, any chance? Thanks!
> 
> I'm sorry. I lost track of the reporter. I'll try to find him.

Found him and asked for a new profile with StyleThread added. https://twitter.com/asadotzler/status/992309975698427904 for future reference.