Version:           unspecified (using KDE 4.6.1) 
OS:                Linux

I had akonadiconsole open while I changed tha password for my email accounts, i.e. akonadi could not access them anymore. I think that is what caused the high cpu usage since there was no other obvious cause, i.e. even kontact was not running.

(gdb) bt
#0  0xb5cdf2a3 in deref (this=0xbff3d018, __in_chrg=<value optimized out>) at ../../src/corelib/arch/qatomic_i386.h:132
#1  ~QSharedDataPointer (this=0xbff3d018, __in_chrg=<value optimized out>) at ../../src/corelib/tools/qshareddata.h:90
#2  QTextFormat::~QTextFormat (this=0xbff3d018, __in_chrg=<value optimized out>) at text/qtextformat.cpp:779
#3  0xb5cc992d in charFormat (this=0xb9f3510, si=0xd887650) at text/qtextformat_p.h:86
#4  QTextEngine::format (this=0xb9f3510, si=0xd887650) at text/qtextengine.cpp:2233
#5  0xb5cc9b15 in QTextEngine::fontEngine (this=0xb9f3510, si=..., ascent=0x0, descent=0x8394178, leading=0x8394178) at text/qtextengine.cpp:1791
#6  0xb5cd5b60 in QTextLine::layout_helper (this=0xbff3d490, maxGlyphs=2147483647) at text/qtextlayout.cpp:1847
#7  0xb5cd7b43 in QTextLine::setLineWidth (this=0xbff3d490, width=<value optimized out>) at text/qtextlayout.cpp:1624
#8  0xb5d16126 in QTextDocumentLayoutPrivate::layoutBlock (this=0x8395c28, bl=..., blockPosition=4444823, blockFormat=..., layoutStruct=0xbff3d8e0, 
    layoutFrom=4444823, layoutTo=2147483647, previousBlockFormat=0xbff3d018) at text/qtextdocumentlayout.cpp:2600
#9  0xb5d1f673 in QTextDocumentLayoutPrivate::layoutFlow (this=0x8395c28, it=..., layoutStruct=0xbff3d8e0, layoutFrom=4444823, layoutTo=2147483647, width=...)
    at text/qtextdocumentlayout.cpp:2404
#10 0xb5d1d708 in QTextDocumentLayoutPrivate::layoutFrame (this=0x8395c28, f=0x8396028, layoutFrom=4444823, layoutTo=2147483647, frameWidth=..., 
    frameHeight=..., parentY=...) at text/qtextdocumentlayout.cpp:2145
#11 0xb5d1e20d in QTextDocumentLayoutPrivate::layoutFrame (this=0x8395c28, f=0x8396028, layoutFrom=137970040, layoutTo=137970040, parentY=...)
    at text/qtextdocumentlayout.cpp:2051
#12 0xb5d21617 in QTextDocumentLayout::doLayout (this=0x8395c18, from=4444823, oldLength=0, length=2143038824) at text/qtextdocumentlayout.cpp:2914
#13 0xb5d21af0 in QTextDocumentLayoutPrivate::ensureLayoutedByPosition (this=0x8395c28, position=12980178) at text/qtextdocumentlayout.cpp:3076
#14 0xb5d22dcb in QTextDocumentLayout::documentChanged (this=0x8395c18, from=12980178, oldLength=0, length=149) at text/qtextdocumentlayout.cpp:2876
#15 0xb5cfb0d6 in QTextDocumentPrivate::finishEdit (this=0x8394308) at text/qtextdocument_p.cpp:1218
#16 0xb5d28f24 in QTextCursor::endEditBlock (this=0xbff3dcfc) at text/qtextcursor.cpp:2486
#17 0xb5cbab2e in QTextControlPrivate::append (this=0x8394278, text=..., format=Qt::AutoText) at text/qtextcontrol.cpp:2822
#18 0xb5cbac12 in QTextControl::append (this=0x8394210, text=...) at text/qtextcontrol.cpp:2828
#19 0xb5f29ddd in QTextEdit::append (this=0x83914a0, text=...) at widgets/qtextedit.cpp:2620
#20 0x0807a62e in ConnectionPage::connectionDataOutput (this=0x81cd688, identifier=..., msg=...)
---Type <return> to continue, or q <return> to quit---
    at /usr/src/debug/kdepim-4.6.40.git.1300056699/akonadiconsole/connectionpage.cpp:70
#21 0x0807a792 in ConnectionPage::qt_metacall (this=0x81cd688, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0xbff3dee4)
    at /usr/src/debug/kdepim-4.6.40.git.1300056699/build/akonadiconsole/connectionpage.moc:78
#22 0xb6a5007d in QMetaObject::metacall (object=0x81cd688, cl=QMetaObject::InvokeMetaMethod, idx=29, argv=0xbff3dee4) at kernel/qmetaobject.cpp:237
#23 0xb6a5f4cc in QMetaObject::activate (sender=0x8396268, m=0x809789c, local_signal_index=1, argv=0xbff3dee4) at kernel/qobject.cpp:3278
#24 0x0808f71f in OrgFreedesktopAkonadiTracerNotificationInterface::connectionDataOutput (this=0x8396268, _t1=..., _t2=...)
    at /usr/src/debug/kdepim-4.6.40.git.1300056699/build/akonadiconsole/tracernotificationinterface.moc:110
#25 0x0808f9ea in OrgFreedesktopAkonadiTracerNotificationInterface::qt_metacall (this=0x8396268, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, 
    _a=0xbff3dffc) at /usr/src/debug/kdepim-4.6.40.git.1300056699/build/akonadiconsole/tracernotificationinterface.moc:86
#26 0xb6889080 in QDBusConnectionPrivate::deliverCall (this=0x81199f0, object=0x8396268, msg=..., metaTypes=..., slotIdx=137970040) at qdbusintegrator.cpp:941
#27 0xb68945a6 in QDBusCallDeliveryEvent::placeMetaCall (this=0x87d1710, object=0x8396268) at qdbusintegrator_p.h:103
#28 0xb6a5edbf in QObject::event (this=0x8396268, e=0x87d1710) at kernel/qobject.cpp:1217
#29 0xb5a42684 in QApplicationPrivate::notify_helper (this=0x80c7108, receiver=0x8396268, e=0x87d1710) at kernel/qapplication.cpp:4462
#30 0xb5a4b427 in QApplication::notify (this=0xbff3e858, receiver=0x8396268, e=0x87d1710) at kernel/qapplication.cpp:3862
#31 0xb64f5591 in KApplication::notify (this=0xbff3e858, receiver=0x8396268, event=0x87d1710) at /usr/src/debug/kdelibs-4.6.1/kdeui/kernel/kapplication.cpp:311
#32 0xb6a4978e in QCoreApplication::notifyInternal (this=0xbff3e858, receiver=0x8396268, event=0x87d1710) at kernel/qcoreapplication.cpp:731
#33 0xb6a4d51c in sendEvent (receiver=0x0, event_type=0, data=0x80ad088) at kernel/qcoreapplication.h:215
#34 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x80ad088) at kernel/qcoreapplication.cpp:1372
#35 0xb6a4d66c in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1265
#36 0xb6a77df4 in sendPostedEvents (s=0x80c9568) at kernel/qcoreapplication.h:220
#37 postEventSourceDispatch (s=0x80c9568) at kernel/qeventdispatcher_glib.cpp:277
#38 0xb3459509 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#39 0xb3459d10 in ?? () from /lib/libglib-2.0.so.0
#40 0xb3459fce in g_main_context_iteration () from /lib/libglib-2.0.so.0
#41 0xb6a77f7b in QEventDispatcherGlib::processEvents (this=0x80b0aa8, flags=...) at kernel/qeventdispatcher_glib.cpp:422
---Type <return> to continue, or q <return> to quit---
#42 0xb5af91da in QGuiEventDispatcherGlib::processEvents (this=0x80b0aa8, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#43 0xb6a48a6d in QEventLoop::processEvents (this=0xbff3e7c4, flags=...) at kernel/qeventloop.cpp:149
#44 0xb6a48c99 in QEventLoop::exec (this=0xbff3e7c4, flags=...) at kernel/qeventloop.cpp:201
#45 0xb6a4d740 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#46 0xb5a403d4 in QApplication::exec () at kernel/qapplication.cpp:3736
#47 0x080800e4 in main (argc=137970040, argv=0x2) at /usr/src/debug/kdepim-4.6.40.git.1300056699/akonadiconsole/main.cpp:65

Reproducible: Didn't try