Bug 221196 - Dolphin occasionally temporarily freezes when built with Nepomuk support and Nepomuk running
Summary: Dolphin occasionally temporarily freezes when built with Nepomuk support and ...
Status: RESOLVED WORKSFORME
Alias: None
Product: dolphin
Classification: Applications
Component: general (show other bugs)
Version: 16.12.2
Platform: Compiled Sources Linux
: NOR normal
Target Milestone: ---
Assignee: Peter Penz
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-01-04 01:27 UTC by Maciej Mrozowski
Modified: 2011-07-03 18:18 UTC (History)
9 users (show)

See Also:
Latest Commit:
Version Fixed In:


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Description Maciej Mrozowski 2010-01-04 01:27:15 UTC
Version:            (using Devel)
Compiler:          gcc (Gentoo 4.3.4 p1.0, pie-10.1.5) 4.3.4 
OS:                Linux
Installed from:    Compiled sources

This is trunk. Nepomuk server up and running with virtuoso storage backend. All seems to be functional but one problem.
During walking through directories dolphin occasionally freezes temporarily (for > 10s) when Nepomuk support is compiled in and Nepomuk server is running.
And it happens when no strigi indexing service is running (it has its own problems with PDF files btw) so in theory no database related critical section is being hit.

Possible reproduction scenarios (well it all qualifies as walking through directories..):
- selecting larger group of directories (which are not subject of Nepomuk indexing!)
- deleteing file or directory
- opening some directories

What's important - it happens for files/directories not being subject of Nepomuk indexing.
Also see similar bug 214765 I reported some time ago.
Comment 1 Maciej Mrozowski 2010-01-04 01:28:58 UTC
Just FYI, disabling Nepomuk server (in system settings) or entirely building dolphin without Nepomuk support fixes any freezing issue.
Comment 2 Martin Tlustos 2010-01-20 18:56:25 UTC
Same (or similar) problem here with me with dolphin 1.3 under Kde 4.3.4 (Kubuntu 9.10 with backports enabled)
File changes (like deleting, renaming etc.) triggers high cpu usage (100% of one cpu core, other is at about 25%) in nepomukstorage process for about 5-10 seconds. Very annoying when trying to rename several files...
Comment 3 Maciej Mrozowski 2010-01-23 03:29:42 UTC
@Martin
I think you're experiencing different bug.

In my case dolphin does not use any CPU (and this is a problem :P) - it's temporarily completely frozen - certainly waiting for some lock. If that matters, all dolphin instances are frozen in such case.

It also occasionally crashes somewhere in dbus library... (note that it's the only dbus client app that crashes on my box, even akonadi and nepomuk don't have such issues, so maybe some dbus API abuse by dolphin?).

Speaking of dbus, it's sys-apps/dbus-1.2.3-r1 (Gentoo). I've recently updated Qt from 4.6.0 to 4.6.1 with no effect. I'll try some newer dbus soon, I really think the problem is in dolphin though.
Comment 4 Maciej Mrozowski 2010-01-23 03:32:58 UTC
One clarification - in description I'v written "What's important - it happens for files/directories not being subject of Nepomuk indexing".

I would like to clarify - it happens "also" for such files.
Comment 5 Christian (Fuchs) 2010-01-30 16:53:49 UTC
Unfortunately I am able to reproduce this with: 

Gentoo Linux
Qt 4.6.* 
KDE 4.3.* / 4.4 (4.3.85,4.3.90,4.3.95) 
dbus 1.3.0
soprano 2.3.70
virtuoso 5.0.12

dolphin freezes on some operations (mainly: delete or move) when compiled with semantic desktop support. The problem disappears when either nepomuk is disabled or dolphin is compiled without support for it. 

If there is any debug output you could use, please tell me where to get it. 

Kind regards, 

Christian
Comment 6 Piotr 2010-02-02 03:14:52 UTC
I can STILL reproduce it in Arch and RC3 packages. It was so annoying i switched to konqueror for file management.
Comment 7 Piotr 2010-02-02 03:34:05 UTC
And turning off nepomuk does help. It no longer freezes when nepomuk is disabled, also dolphin was freezing both with files under nepomuk search and outside them.
Comment 8 Philipp Schmidt 2010-02-02 11:24:10 UTC
*** This bug has been confirmed by popular vote. ***
Comment 9 Maciej Mrozowski 2010-02-04 00:58:22 UTC
Trying out newer dbus (1.3.0, "testing" Gentoo repo) didn't help - same behaviour.
As I mentioned, apart from occasionally freezing - the same dolphin crashes very often as well. Here's backtrace (dbus-1.2.3) :

Application: Dolphin (dolphin), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fed4356a740 (LWP 30347))]

Thread 2 (Thread 0x7fed33a64910 (LWP 30381)):
#0  0x00007fed3f4227b2 in select () from /lib64/libc.so.6
#1  0x00007fed40630327 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#2  0x00007fed40570491 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#3  0x00007fed3d0108dc in start_thread () from /lib64/libpthread.so.0
#4  0x00007fed3f42a19d in clone () from /lib64/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fed4356a740 (LWP 30347)):
[KCrash Handler]
#5  _dbus_pthread_mutex_lock (mutex=<value optimized out>) at dbus-sysdeps-pthread.c:128
#6  0x00007fed3bf2c3fd in _dbus_connection_lock (connection=0x7fed2c010e88) at dbus-connection.c:355
#7  0x00007fed3bf3b51c in _dbus_pending_call_get_connection_and_lock (pending=0x7fed2c0044f0) at dbus-pending-call.c:309
#8  0x00007fed3bf301e6 in reply_handler_timeout (data=0x61006e0062006d) at dbus-connection.c:3116
#9  0x00007fed4097a227 in ?? () from /usr/lib64/qt4/libQtDBus.so.4
#10 0x00007fed4065ebec in QObject::event(QEvent*) () from /usr/lib64/qt4/libQtCore.so.4
#11 0x00007fed3fb7c95f in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#12 0x00007fed3fb849ec in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#13 0x00007fed412678a4 in KApplication::notify (this=0x7fffaff41310, receiver=0x159b630, event=0x7fffaff40fd0)
    at /var/tmp/portage/kde-base/kdelibs-4.4.9999/work/kdelibs-4.4.9999/kdeui/kernel/kapplication.cpp:302
#14 0x00007fed40650744 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/qt4/libQtCore.so.4
#15 0x00007fed406798be in ?? () from /usr/lib64/qt4/libQtCore.so.4
#16 0x00007fed40676421 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#17 0x00007fed3b86ea13 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#18 0x00007fed3b87196c in ?? () from /usr/lib/libglib-2.0.so.0
#19 0x00007fed3b871aee in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#20 0x00007fed40676174 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#21 0x00007fed3fc0ba26 in ?? () from /usr/lib64/qt4/libQtGui.so.4
#22 0x00007fed4064f404 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#23 0x00007fed4064f74f in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#24 0x00007fed4065172e in QCoreApplication::exec() () from /usr/lib64/qt4/libQtCore.so.4
#25 0x0000000000439ad5 in main (argc=6, argv=0x7fffaff41818) at /var/tmp/portage/kde-base/dolphin-4.4.9999/work/dolphin-4.4.9999/dolphin/src/main.cpp:101
Comment 10 Maciej Mrozowski 2010-02-04 01:10:09 UTC
One fellow on #akonadi observed interesting issue with akonadi - I wonder
whether it's related to nepomuk issue in dolphin - dbus abuse by either dolphin
or nepomuk could cause dbus freezes/crashes afterall ...

[02-02][19:14:16] <andres> Anybody got a fast idea why akonadi opens 10k dbus
connections?
[02-02][19:14:59] <andres> (1.3.0)
[02-02][19:19:59] <tmcguire> it opens one dbus connection per client session,
but there hardly can be 10k sessions...
[02-02][19:20:02] <tmcguire> So no idea.
[02-02][19:27:52] <reavertm> andres: btw, how do you check that number? I
wonder whether it's related to dolphin bug 221196
[02-02][19:27:55] <bugbot> kde bug 221196 in dolphin (general) "Dolphin
occasionally temporarily freezes when built with Nepomuk support and Nepomuk
running" [Normal,New] https://bugs.kde.org/221196
[02-02][19:29:31] <andres> reavertm: looking at the fds and bus-send
--print-reply --session --dest=org.freedesktop.DBus /org/freedesktop/DBus
org.freedesktop.DBus.ListNames and dbus-send --print-reply --session
--dest=org.freedesktop.DBus /org/freedesktop/DBus
org.freedesktop.DBus.GetConnectionUnixProcessID string::whatever
[02-02][19:30:55] <andres> reavertm: combined with the bug that dbus accepts
more connections than allowed fds and then poll()s on invalid fds in a endless
loop thats rather annoying.
[02-02][19:32:04] <andres> reavertm: it might be the cause of those bugs - I
dont actually really use kde except kdepim...
[02-02][19:37:06] <andres> It looses about 20connections/minute...

This is grave bug really, We may have no option but to disable nepomuk for dolphin at build time for Gentoo or at least strongly discourage our users from enabling it - but that pretty much defeats the purpose of having nepomuk at all.
Comment 11 Maciej Mrozowski 2010-02-11 17:07:59 UTC
It doesn't seem to be a problem here anymore, with soprano-2.4.0(.1), KDE 4.4.0 (4.4 branch really), and Virtuoso 6.1.0.
Comment 12 Piotr 2010-02-11 17:24:32 UTC
I also must say i didn't notice that problem in in Arch (Virtuoso 6.1.0, Soprano 2.3.73, and 4.4.0), looks like it solved itself by evolution ;)??
Comment 13 Maciej Mrozowski 2010-03-23 12:41:44 UTC
I'll close this one as fixed, and reopen if it appears again.
Comment 14 Maciej Mrozowski 2010-07-23 02:10:39 UTC
And issue is back in 4.5. This time probably because strigi indexer seems to be run on demand on files shown in dolphin. Reopening.

KDE SC 4.5 svn branch, Qt-4.6.3, soprano-2.4.63, virtuoso-6.1.2
Comment 15 Frank Reininghaus 2010-09-26 01:23:40 UTC
Could be related to a D-Bus bug which leads to freezes and crashes, see bug 226725, bug 232054. That issue is fixed in D-Bus 1.3.1 and later.
Comment 16 Jack 2010-12-05 15:03:16 UTC
Confirming in 4.5.4 on Gentoo
Comment 17 Maciej Mrozowski 2011-07-03 16:52:42 UTC
For everyone who spotted this issue before, please recheck with KDE SC 4.6.x.

For me issue is long gone.
Comment 18 Philipp Schmidt 2011-07-03 17:13:24 UTC
Also not present in 4.7-rc1
Comment 19 Piotr 2011-07-03 18:07:31 UTC
Same here, with both the 4.6 and 4.7 rc1 (built on gentoo) works with no problems.
Comment 20 Frank Reininghaus 2011-07-03 18:18:57 UTC
Thanks for the feedback! I'll close the report then. If you see this issue again in in KDE 4.7 and later (running with D-Bus 1.4 or later), please file a new report. Thanks for your help.