I see very high cpu usage on "MainThread" with some trunk tb builds. It is enough to make the laptop fan run while nothing is happening (tb idling). This seems to depend on the present pulled tip version. So it comes and goes. I also notice when this occurs that tb is very slow to start up, but once started, even with fan running full speed, it runs OK.

Not sure if this tells anything but I attached with gdb to running tb and see this backtrace (bt) with MainThread (thread 1) running 100% cpu per top.

Edit: my current "hg pull -u" points are:
Mozilla Central: changeset: 542131:f4703bddd567
Comm Central: changeset: 30212:76593bdd0358

Not sure if this is always the case, but right now I can start tb and MainThread settles down to a reasonable CPU usage in top (much less than 100% and not always at the "top" of the list). I can load an email with several moderately sized jpegs and it goes high for a while and then settles back down. But when I load an email with inline 16Meg png, it goes to 200% and then "settles" back to 100% and always on "top" with fan running until I shutdown tb.

(Trunk, not 78)

profiler issues are being worked on in bug 1631919

Mark has instructions for profiler at https://github.com/thunderbird-conversations/thunderbird-conversations/wiki/Profiling-Conversation's-Performance

(In reply to Wayne Mery (:wsmwk) from comment #5)

Mark has instructions for profiler at https://github.com/thunderbird-conversations/thunderbird-conversations/wiki/Profiling-Conversation's-Performance

Thanks, will try that at some point. Also, FWIW, with trunk I'm unable to open PDF attachments. Don't know why but probably subject of another bug report. (Pdf's ok now.)

If this happened with trunk you should also be able to reproduce with the current beta.

Still seeing this?

I think I saw it (heard fan running hard) yesterday but didn't check cpu usage in top. But before seeing your question I updated to a new tip but don't see a problem right now. Every now and then MainThread or Thunderbird tasks appear on top with 1 to 3% cpu and not kicking the fan on. (Fan on seems to occur when cpu goes to constant 100% or more.)
I'll keep an eye on this and see if high cpu % happens again.

I saved a few large and old mbox files in Local Folders. After that I saw pretty constant cpu usage at about 80%. Seems to have settled down now. Maybe some background indexing going on?

(In reply to gene smith from comment #10)

I saved a few large and old mbox files in Local Folders. After that I saw pretty constant cpu usage at about 80%. Seems to have settled down now. Maybe some background indexing going on?

yes

so it sounds like the original issue is gone?

Yes, I think this was a false alarm, probably just background gloda indexing when I add a ton of new stuff to folders. I'll close it.