1305031 - Slow addon warning detects all addons as slow when running some computationally intensive task outside of Firefox

Status: RESOLVED WONTFIX

(Toolkit :: Performance Monitoring, defect)

Description

[Marco Castelluccio [:marco]]

I'm not sure what is the right Product/Component.

For example, if I build Firefox, I see the slow addon warning popping up for all addons. It should only show up if an addon is causing Firefox to be slower.

Comment 1

[David Teller [:Yoric] - still alive but not very active]

Mmmh... that's not good.
Is it reproducible? Did you notice if Firefox was actually slower at the time?

Comment 2

[Marco Castelluccio [:marco]]

(In reply to David Rajchenbach-Teller [:Yoric] (please use "needinfo") from comment #1)
> Is it reproducible?

I'm not sure I can reproduce it consistently, but I've seen it several times.

> Did you notice if Firefox was actually slower at the time?

Sometimes it was noticeably slower, sometimes it wasn't.

Comment 3

[David Teller [:Yoric] - still alive but not very active]

Basically, what happens is when the slow add-on watcher detects that Firefox is being janky (as in misses too many frames too many times in a few minutes), it tries to assign blame and looks at what inside Firefox was consuming too much CPU time during these skipped frames. I suspect that in this case, the computer is being so slow that Firefox skips frames, and these add-ons are indeed consuming too much CPU time, but they are not the cause.

I'm not sure what kind of counter-measure we could think of for this situation, though.

Comment 4

[Marco Castelluccio [:marco]]

(In reply to David Teller [:Yoric] (please use "needinfo") from comment #3)
> Basically, what happens is when the slow add-on watcher detects that Firefox
> is being janky (as in misses too many frames too many times in a few
> minutes), it tries to assign blame and looks at what inside Firefox was
> consuming too much CPU time during these skipped frames. I suspect that in
> this case, the computer is being so slow that Firefox skips frames, and
> these add-ons are indeed consuming too much CPU time, but they are not the
> cause.
> 
> I'm not sure what kind of counter-measure we could think of for this
> situation, though.

Can we detect if there's some other process which is consuming way more CPU
time than Firefox?

Comment 5

[David Teller [:Yoric] - still alive but not very active]

> Can we detect if there's some other process which is consuming way more CPU time than Firefox?

I don't know of any reliable way to do this.

Comment 6

[Julien Cristau [:jcristau] (back April 22)]

Mass wontfix for bugs affecting firefox 52.

Comment 7

[YF (Yang)]

To wontfix as bug 1309946 removed the feature?

Comment 8

[Florian Quèze [:florian]]

about:performance is being redesigned; mass closing the bugs related to parts of the current about:performance page that we are not keeping.

Our goals with the redesign are to reduce the overhead caused by having the page opened, increase the reliability of the displayed information, and make the offered information actionable for most users. The back-end work is being tracked in bug 1419681.