Comment 61 for bug 109943

(In reply to David von Oheimb from comment #39)
> Thanks Wayne for bringing attention back also to this bug.
>
> I can confirm that the bug still exists with the latest released TB version
> 31.3.0 with a cpu usage increase of about 12-13% on my Macbook Air....
>
> I suspect that this waste of CPU (and battery on mobile devices!) is due to
> the same careless chunk of code performing a busy loop somewhere deep in
> Mozilla's TCP client connect implementation.

David, can you do a performance profile during a period of high CPU using the procedure at https://developer.mozilla.org/en-US/docs/Tools/Remote_Debugging/Thunderbird which uses Firefox as the recorder

- follow instructions at https://developer.mozilla.org/en-US/docs/Tools/Remote_Debugging/Thunderbird
- after connect, pick "main"
- click "Performance" in the developer tool menu
- click "start recording performance" in the center
- do some actions in thunderbird which cause the problem or behavior to be recorded
- click "stop recording performance" in the center
- click "Save" one the left
- email the json file or attach to this bug report