knotify4 uses 100% CPU despite not Qt/Kde apps being in-use

[Paul Sladen]

Binary package hint: kdebase-runtime

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 7387 sladen 20 0 82728 11m 9296 S 100 0.4 14:54.14 knotify4

Fresh logout+login. 'knotify4' using 100% CPU. What do I need to look for?

DistroRelease: Ubuntu 11.04
Package: kdebase-runtime 4:4.6.1-0ubuntu1
ExecutablePath: /usr/bin/knotify4

[Paul Sladen (sladen)]

http://forums.opensuse.org/applications/415387-knotify4-consuming-100-cpu.html

gdb -p ...
(gdb) thread apply all bt
Thread 2 (Thread 0xb56c1b70 (LWP 7392)):
#0 0x00449416 in __kernel_vsyscall ()
#1 0x0090ee06 in poll () from /lib/libc.so.6
#2 0x0262f97b in g_qsort_with_data (pbase=0xb4d01480, total_elems=2, size=4294967295, compare_func=0xb4d01480, user_data=0x2)
    at /build/buildd/glib2.0-2.28.3/./glib/gqsort.c:158
#3 0x0261f2df in g_main_context_iterate (context=0x8405934, block=40040784, dispatch=1, self=<value optimised out>)
    at /build/buildd/glib2.0-2.28.3/./glib/gmain.c:3076
#4 0x0261f654 in g_main_loop_ref (loop=0x8405930) at /build/buildd/glib2.0-2.28.3/./glib/gmain.c:3200
#5 0x015c954c in QEventDispatcherGlib::processEvents (this=0x83fb8b0, flags=...) at kernel/qeventdispatcher_glib.cpp:422
#6 0x0159b299 in QEventLoop::processEvents (this=0xb56c1290, flags=...) at kernel/qeventloop.cpp:149
#7 0x0159b532 in QEventLoop::exec (this=0xb56c1290, flags=...) at kernel/qeventloop.cpp:201
#8 0x014a52a0 in QThread::exec (this=0x84049e8) at thread/qthread.cpp:492
#9 0x0157cfeb in QInotifyFileSystemWatcherEngine::run (this=0x84049e8) at io/qfilesystemwatcher_inotify.cpp:248
#10 0x014a7da2 in QThreadPrivate::start (arg=0x84049e8) at thread/qthread_unix.cpp:320
#11 0x05a08e99 in start_thread () from /lib/libpthread.so.0
#12 0x0091d5ce in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb77a7ac0 (LWP 7387)):
#0 0x00449416 in __kernel_vsyscall ()
#1 0x05a0d48c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2 0x0092b28d in pthread_cond_wait () from /lib/libc.so.6
#3 0x014a8467 in wait (this=0x84044e8, mutex=0x84044d0, time=4294967295) at thread/qwaitcondition_unix.cpp:88
#4 QWaitCondition::wait (this=0x84044e8, mutex=0x84044d0, time=4294967295) at thread/qwaitcondition_unix.cpp:160
#5 0x014a74cf in QThread::wait (this=0x84049e8, time=4294967295) at thread/qthread_unix.cpp:722
#6 0x0156fc87 in QFileSystemWatcher::~QFileSystemWatcher (this=0x83fa888, __in_chrg=<value optimised out>) at io/qfilesystemwatcher.cpp:446
#7 0x0156fd52 in QFileSystemWatcher::~QFileSystemWatcher (this=0x83fa888, __in_chrg=<value optimised out>) at io/qfilesystemwatcher.cpp:462
#8 0x015afb97 in QObjectPrivate::deleteChildren (this=0x8404910) at kernel/qobject.cpp:1964
#9 0x015b43af in QObject::~QObject (this=0x8404398, __in_chrg=<value optimised out>) at kernel/qobject.cpp:946
#10 0x00204e5b in Solid::Backends::Fstab::FstabWatcher::~FstabWatcher (this=0x8404398, __in_chrg=<value optimised out>)
    at ../../../solid/solid/backends/fstab/fstabwatcher.cpp:48
#11 0x00204e92 in Solid::Backends::Fstab::FstabWatcher::~FstabWatcher (this=0x8404398, __in_chrg=<value optimised out>)
    at ../../../solid/solid/backends/fstab/fstabwatcher.cpp:51
#12 0x00204d05 in destroy () at ../../../solid/solid/backends/fstab/fstabwatcher.cpp:30
#13 0x0018dfbb in Solid::CleanUpGlobalStatic::~CleanUpGlobalStatic (this=0x2218c8, __in_chrg=<value optimised out>)
    at ../../../solid/solid/soliddefs_p.h:67
#14 0x0087ca1f in ?? () from /lib/libc.so.6
#15 0x0087ca7f in exit () from /lib/libc.so.6
#16 0x00b6cd8b in ?? () from /usr/lib/libQtGui.so.4
#17 0x0068311a ...

[MMlosh (mmlosh)]

I don't use kde, but I have some QT apps.. which pull phonon, kdebase, and knotify as well.

This never happened before.
But I have a possible clue --- stopped (pulseaudio -k) and started(pulseaudio --start --log-taget=syslog) the pulseaudio server, because it was failing to notice new audio devices

Was that caused by some sort of phonon's "new audio device found" message or something?

[MMlosh (mmlosh)]

(But I upgraded to natty yesterday, so there are too many factors)
I remember deinstalling KWin, thought