1363297 - Opening web link triggers 100% CPU usage in kmozillahelper (KDE component)

Status: RESOLVED WORKSFORME

(Thunderbird :: General, defect)

Description

[Vadym Krevs]

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.96 Safari/537.36

Steps to reproduce:

openSUSE 42.2, Thunderbird 52.1.0 from http://download.opensuse.org/repositories/mozilla/openSUSE_Leap_42.2/x86_64/.

Click on a new unread HTML email with web links.



Actual results:

Thunderbird seems to spawn a new instance of kmozillahelper and kmozillahelper spends up to a minute enumerating plugins in /usr/lib64/qt5/plugins/kf5/ and services in /usr/share/kservices5/ fully utilizing one CPU core.

This happens for each new unread HTML email.

I have reported this here in openSUSE bugzilla https://bugzilla.suse.com/show_bug.cgi?id=1037806

and the opensuse developers seem to think it is a Thunderbird bug (see comment #4 in the opensuse bug report).


Expected results:

Thunderbird/Kmozillahelper should not trigger high CPU consumption for each HTML email with web links.

Comment 1

[Jorg K (CEST = GMT+2)]

Hmm, why is this a Thunderbird bug? kmozillahelper is a component of KDE, so why don't you complain to them?
Surely, digging around in KDE plugins (qt5/plugins) has nothing to do with Mozilla software.

Should I be mistaken, please re-open the bug.

Comment 2

[Wolfgang Rosenauer [:wolfiR]]

According to https://bugzilla.suse.com/show_bug.cgi?id=1037806 the reason why this is a problem is that:
"The issue is that it calls nsMIMEInfoUnix::GetHasDefaultHandler way to often with totally nonsensical parameters, like "subsystem", "c", "C", "Zc"."

This looks like there are really non-useful calls to GetHasDefaultHandler which also is expensive with Gtk but not as visible as it is in the case of the external integration with KDE.

Comment 3

[Wayne Mery (:wsmwk)]

Is this also a problem prior to version 52.1.0, i.e. is this a regression??


(In reply to Wolfgang Rosenauer [:wolfiR] from comment #2)
> ...
> This looks like there are really non-useful calls to GetHasDefaultHandler
> which also is expensive with Gtk but not as visible as it is in the case of
> the external integration with KDE.

https://bugzilla.suse.com/show_bug.cgi?id=1037806#c4
"I see a ton of senseless queries for HANDLEREXISTS, so it's a bug in thunderbird."

Comment 4

[Vadym Krevs]

This wasn't the case with earlier TB versions.

Comment 5

[tonemgub]

Does this issue still exist in 52.9.1  or v60.0 of Thunderbird? 
(Unable to reproduce here but possibly different desktop configuration than OP)


As far as I can tell - The component mentioned is in toolkit, not Thunderbird: https://dxr.mozilla.org/comm-central/search?q=nsMIMEInfoUnix&redirect=false

Comment 6

[Vadym Krevs]

I've upgraded to openSUSE Leap 15.0 earlier this year, which includes both v52.9.1 and v60, and neither appear to trigger this  problem anymore.

Comment 7

[Wayne Mery (:wsmwk)]

Thanks