1634063 - After opening the multiprocess browser console it hangs and is not usable the first couple of seconds

Status: NEW

(DevTools :: Console, defect, P2)

Description

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:77.0) Gecko/20100101 Firefox/77.0 ID:20200423054309

Opening the multiprocess browser console causes the window to hang, and very slowly react on user input. The beach ball is visible mostly all the time.

Here a profile as generated after opening the window and waiting for about 30s:

https://bit.ly/2KHq4h1

As it is visible in the profile we spend about 66% of the time in setTimeout handler specifically for: resource://devtools/client/webconsole/webconsole-wrapper.js:318

Note that this happens each and every time when I open the console.

Comment 1

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Also note that the memory usage goes up by ~2GB within those couple seconds and nothing gets released again!

Comment 2

[:Harald Kirschner :digitarald]

Henrik, do you remember how many messages you had in the Console, on a rough scale between some - hundreds - thousands?

Comment 3

[Henrik Skupin [:whimboo][⌚️UTC+1]]

No, I cannot tell. But the Firefox process was running a couple of days. I never closed it but only hibernated the machine. If it's related to the amount of message outside of the current view, maybe some kind of lazy loading might make sense here.