Bug 334206

Summary: While IMAP/maildir resource synchronizes a folder KMail blocks on switching to a different folder
Product: [Frameworks and Libraries] Akonadi Reporter: Martin Steigerwald <Martin>
Component: serverAssignee: kdepim bugs <kdepim-bugs>
Status: RESOLVED WORKSFORME    
Severity: normal CC: dvratil
Priority: NOR    
Version: GIT (master)   
Target Milestone: ---   
Platform: Debian unstable   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: gdb backtrace with all threads and with relevant debug packages installed.

Description Martin Steigerwald 2014-05-02 08:39:21 UTC 
I found that while Akonadi maildir resources synchronizes a folder certain operations in KMail are block. I found this to be the case with switching to a different folder. It takes minutes before KMail responds again.

Reproducible: Always

Steps to Reproduce:
1. Have a maildir resource.
2. Have a large folder.
3. Have Akonadi synchronizing it.
4. Click on a different folder in kmail.
Actual Results:  
KMail is blocked for minutes. It just doesn´t respond to clicks while Akonadi maildir resource is 100% busy. If I kill this process KMail *immediately* responds to the last user request, but then is blocked again after Akonadi restarted the maildir resource process.

Expected Results:  
KMail responds to user requests immediately or almost immediately. KMail´s GUI is never blocked according to the following design goal of Akonadi:

Concurrent access allows background activity independent of UI client

    Syncing mail, calendar, addressbooks to remote servers
    Syncing with mobile devices
    Permits semantic desktop infrastructure to access PIM data
    Archiving
    Indexing
    Out-of-process search 

http://community.kde.org/KDE_PIM/Akonadi#Features


I can share a collection of large folders as xz archive, including kernel-ml folder with about 220000 mails. Dan already got a copy of these from me.

I/O is not the issue here. Akonadi is hogging the CPU 100%, SSDs are *not* fully ultilizes.

I am tempted to raise the bug priority to more than normal, as this bug makes KMail unusable for minutes.

I am currently using Akonadi git 1d1969c65c10c9d3f054f6dafb0f5a2a97d48281.
Comment 1 Daniel Vrátil 2014-05-02 08:54:39 UTC 
I assume by blocked you mean that the application is still responsive (you can click on stuff etc), but it just shows 'Opening folder...' and nothing is happening?

If KMail really blocks (as in becoming unresponsive), please provide a backtrace.
Comment 2 Martin Steigerwald 2014-05-02 09:09:59 UTC 
No, I mean blocked. It doesn´t respond to clicks anymore for minutes. A backtrace done by attaching GDB to a process? And of which process? KMail, Akonadi server or maildir resource?

Please provide some more hints on how to do this in order to be useful.
Comment 3 Martin Steigerwald 2014-05-02 09:11:10 UTC 
For the backtrace to be useful I mean. Well, I bet KMail as it is the blocked process.
Comment 4 Martin Steigerwald 2014-05-02 09:27:38 UTC 
Is this useful? Backtrace of KMail while being blocked on folder system after Akonadi restart.

(gdb) continue
Continuing.
^C
Program received signal SIGINT, Interrupt.
0x00007ffd9bde48ed in poll () at ../sysdeps/unix/syscall-template.S:81
81      in ../sysdeps/unix/syscall-template.S

I don´t know how else to get a bt trace of a running process. If there is a more suitable method please tell me.

(gdb) bt full
#0  0x00007ffd9bde48ed in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007ffd921665f8 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
No symbol table info available.
#2  0x00007ffd9216559f in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
No symbol table info available.
#3  0x00007ffd9214fc4c in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
No symbol table info available.
#4  0x00007ffd921505f9 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
No symbol table info available.
#5  0x00007ffd9a23dce7 in ?? () from /usr/lib/x86_64-linux-gnu/libQtDBus.so.4
No symbol table info available.
#6  0x00007ffd9a27c97c in ?? () from /usr/lib/x86_64-linux-gnu/libQtDBus.so.4
No symbol table info available.
#7  0x00007ffd9749e097 in MailCommon::FolderCollection::identity() const () from /usr/lib/libmailcommon.so.4
No symbol table info available.
#8  0x00007ffd9d803792 in ?? () from /usr/lib/libkmailprivate.so.4
No symbol table info available.
#9  0x00007ffd97a8677f in MessageList::StorageModel::containsOutboundMessages() const () from /usr/lib/libmessagelist.so.4
No symbol table info available.
#10 0x00007ffd97a3e76d in ?? () from /usr/lib/libmessagelist.so.4
No symbol table info available.
#11 0x00007ffd9c7666aa in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#12 0x00007ffd9c7b038d in QAbstractItemModel::headerDataChanged(Qt::Orientation, int, int) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#13 0x00007ffd97a85c6a in MessageList::StorageModel::Private::onSelectionChanged() () from /usr/lib/libmessagelist.so.4
No symbol table info available.
#14 0x00007ffd9c7666aa in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#15 0x00007ffd9d1c7ff7 in QItemSelectionModel::selectionChanged(QItemSelection const&, QItemSelection const&) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#16 0x00007ffd9d1cd651 in QItemSelectionModel::emitSelectionChanged(QItemSelection const&, QItemSelection const&) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#17 0x00007ffd9d1cde23 in QItemSelectionModel::select(QItemSelection const&, QFlags<QItemSelectionModel::SelectionFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#18 0x00007ffd97a827e3 in MessageList::Pane::Private::onSelectionChanged(QItemSelection const&, QItemSelection const&) ()
   from /usr/lib/libmessagelist.so.4
No symbol table info available.
#19 0x00007ffd9c7666aa in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#20 0x00007ffd9d1c7ff7 in QItemSelectionModel::selectionChanged(QItemSelection const&, QItemSelection const&) ()
---Type <return> to continue, or q <return> to quit---
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#21 0x00007ffd9d1cd651 in QItemSelectionModel::emitSelectionChanged(QItemSelection const&, QItemSelection const&) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#22 0x00007ffd9d1cde23 in QItemSelectionModel::select(QItemSelection const&, QFlags<QItemSelectionModel::SelectionFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#23 0x00007ffd9d1b9e1a in QTreeViewPrivate::select(QModelIndex const&, QModelIndex const&, QFlags<QItemSelectionModel::SelectionFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#24 0x00007ffd9d1ba71c in QTreeView::setSelection(QRect const&, QFlags<QItemSelectionModel::SelectionFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#25 0x00007ffd9d17a4fa in QAbstractItemView::mousePressEvent(QMouseEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#26 0x00007ffd9ccd1b3b in QWidget::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#27 0x00007ffd9d07043e in QFrame::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#28 0x00007ffd9d17fd13 in QAbstractItemView::viewportEvent(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#29 0x00007ffd9d1be930 in QTreeView::viewportEvent(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#30 0x00007ffd9c752586 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) ()
   from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#31 0x00007ffd9cc826ac in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#32 0x00007ffd9cc88e3a in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#33 0x00007ffd9e4ef76a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
No symbol table info available.
#34 0x00007ffd9c75241d in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#35 0x00007ffd9cc88633 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#36 0x00007ffd9ccfa33b in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#37 0x00007ffd9ccf8dac in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#38 0x00007ffd9cd20712 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#39 0x00007ffd9352ee04 in g_main_dispatch (context=0x6e7060) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3064
---Type <return> to continue, or q <return> to quit---
        dispatch = 0x7ffd9cd20530
        prev_source = 0x0
        was_in_call = 0
        user_data = 0x0
        callback = 0x0
        cb_funcs = <optimized out>
        cb_data = 0x0
        need_destroy = <optimized out>
        source = 0x6e8200
        current = 0x677190
        i = 0
#40 g_main_context_dispatch (context=context@entry=0x6e7060) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3663
No locals.
#41 0x00007ffd9352f048 in g_main_context_iterate (context=context@entry=0x6e7060, block=block@entry=1, dispatch=dispatch@entry=1, 
    self=<optimized out>) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3734
        max_priority = 2147483647
        timeout = 146
        some_ready = 1
        nfds = <optimized out>
        allocated_nfds = 17
        fds = 0x3f139c0
#42 0x00007ffd9352f0ec in g_main_context_iteration (context=0x6e7060, may_block=1) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3795
        retval = <optimized out>
#43 0x00007ffd9c77f655 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#44 0x00007ffd9cd207c6 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#45 0x00007ffd9c750fef in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#46 0x00007ffd9c7512e5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#47 0x00007ffd9c756ab9 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#48 0x0000000000402d1a in ?? ()
No symbol table info available.
#49 0x00007ffd9bd2bb45 in __libc_start_main (main=0x402280, argc=3, argv=0x7fff8dc10008, init=<optimized out>, fini=<optimized out>, 
    rtld_fini=<optimized out>, stack_end=0x7fff8dc0fff8) at libc-start.c:287
        result = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {0, 6054434086896432828, 4207045, 140735571623936, 0, 0, -6054332991946459460, 
                -6053229204588169540}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x403620 <__libc_csu_init>, 0x7fff8dc10008}, data = {
              prev = 0x0, cleanup = 0x0, canceltype = 4208160}}}
        not_first_call = <optimized out>
#50 0x00000000004031ee in _start ()
No symbol table info available.
(gdb) continue
Continuing.
[New Thread 0x7ffd70c34700 (LWP 8606)]
[New Thread 0x7ffd7212f700 (LWP 8607)]
[New Thread 0x7ffd735cf700 (LWP 8608)]
^C
Program received signal SIGINT, Interrupt.
0x00007ffd9bde48ed in poll () at ../sysdeps/unix/syscall-template.S:81
81      in ../sysdeps/unix/syscall-template.S
(gdb) bt full
#0  0x00007ffd9bde48ed in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007ffd9352efe4 in g_main_context_poll (priority=2147483647, n_fds=10, fds=0x3f139c0, timeout=189, context=0x6e7060)
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:4028
        poll_func = 0x7ffd9353db40 <g_poll>
#2  g_main_context_iterate (context=context@entry=0x6e7060, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3729
        max_priority = 2147483647
        timeout = 189
        some_ready = <optimized out>
        nfds = 10
        allocated_nfds = 17
        fds = 0x3f139c0
#3  0x00007ffd9352f0ec in g_main_context_iteration (context=0x6e7060, may_block=1) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3795
        retval = <optimized out>
#4  0x00007ffd9c77f655 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#5  0x00007ffd9cd207c6 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
No symbol table info available.
#6  0x00007ffd9c750fef in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#7  0x00007ffd9c7512e5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#8  0x00007ffd9c756ab9 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
No symbol table info available.
#9  0x0000000000402d1a in ?? ()
No symbol table info available.
#10 0x00007ffd9bd2bb45 in __libc_start_main (main=0x402280, argc=3, argv=0x7fff8dc10008, init=<optimized out>, fini=<optimized out>, 
    rtld_fini=<optimized out>, stack_end=0x7fff8dc0fff8) at libc-start.c:287
        result = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {0, 6054434086896432828, 4207045, 140735571623936, 0, 0, -6054332991946459460, 
                -6053229204588169540}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x403620 <__libc_csu_init>, 0x7fff8dc10008}, data = {
              prev = 0x0, cleanup = 0x0, canceltype = 4208160}}}
        not_first_call = <optimized out>
#11 0x00000000004031ee in _start ()
No symbol table info available.
(gdb) continue
Continuing.
[Thread 0x7ffd735cf700 (LWP 8608) exited]
[New Thread 0x7ffd735cf700 (LWP 8615)]
[Thread 0x7ffd7212f700 (LWP 8607) exited]
[Thread 0x7ffd735cf700 (LWP 8615) exited]
[Thread 0x7ffd70c34700 (LWP 8606) exited]


Seems to wait von dbus. I will installed dbus debug and qt debug stuff and retry.
Comment 5 Martin Steigerwald 2014-05-02 09:47:56 UTC 
Created attachment 86400 [details]
gdb backtrace with all threads and with relevant debug packages installed.

Okay, here is a backtrace according to your description. Is this useful?

(gdb) continue
Continuing.
[New Thread 0x7ffd70c34700 (LWP 8992)]
[Thread 0x7ffd70c34700 (LWP 8992) exited]
^C
Program received signal SIGINT, Interrupt.
0x00007ffd9bde48ed in poll () at ../sysdeps/unix/syscall-template.S:81
81      in ../sysdeps/unix/syscall-template.S
(gdb) t a a bt

Thread 4 (Thread 0x7ffd79f55700 (LWP 4372)):
#0  0x00007ffd9bde8df3 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffd9c72f0b1 in QProcessManager::run (this=0x7ffd9cab9540 <processManager()::processManager>) at io/qprocess_unix.cpp:270
#2  0x00007ffd9c6502bf in QThreadPrivate::start (arg=0x7ffd9cab9540 <processManager()::processManager>) at thread/qthread_unix.cpp:349
#3  0x00007ffd996bf062 in start_thread (arg=0x7ffd79f55700) at pthread_create.c:312
#4  0x00007ffd9bdefbfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 3 (Thread 0x7ffd78dc9700 (LWP 4375)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007ffd8f8d07d2 in WTF::TCMalloc_PageHeap::scavengerThread (this=<optimized out>) at wtf/FastMalloc.cpp:2499
#2  0x00007ffd8f8d0809 in WTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at wtf/FastMalloc.cpp:1622
#3  0x00007ffd996bf062 in start_thread (arg=0x7ffd78dc9700) at pthread_create.c:312
#4  0x00007ffd9bdefbfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 2 (Thread 0x7ffd73fff700 (LWP 4376)):
#0  0x00007ffd9bde48ed in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffd9352efe4 in g_main_context_poll (priority=2147483647, n_fds=1, fds=0x7ffd6c003080, timeout=9999, context=0x7ffd6c0009a0)
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:4028
#2  g_main_context_iterate (context=context@entry=0x7ffd6c0009a0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3729
#3  0x00007ffd9352f0ec in g_main_context_iteration (context=0x7ffd6c0009a0, may_block=1) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3795
#4  0x00007ffd9c77f676 in QEventDispatcherGlib::processEvents (this=0x7ffd6c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:427
#5  0x00007ffd9c750fef in QEventLoop::processEvents (this=this@entry=0x7ffd73ffece0, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007ffd9c7512e5 in QEventLoop::exec (this=this@entry=0x7ffd73ffece0, flags=...) at kernel/qeventloop.cpp:204
#7  0x00007ffd9c64dbef in QThread::exec (this=<optimized out>) at thread/qthread.cpp:538
#8  0x00007ffd9c6502bf in QThreadPrivate::start (arg=0xdf8f80) at thread/qthread_unix.cpp:349
#9  0x00007ffd996bf062 in start_thread (arg=0x7ffd73fff700) at pthread_create.c:312
#10 0x00007ffd9bdefbfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 1 (Thread 0x7ffd9eaba900 (LWP 4369)):
#0  0x00007ffd9bde48ed in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffd9216ca08 in poll (__timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:46
#2  _dbus_poll (fds=<optimized out>, n_fds=<optimized out>, timeout_milliseconds=<optimized out>) at ../../dbus/dbus-sysdeps-unix.c:2558
#3  0x00007ffd921665f8 in socket_do_iteration (transport=0x6bec70, flags=6, timeout_milliseconds=<optimized out>) at ../../dbus/dbus-transport-socket.c:1117
#4  0x00007ffd9216559f in _dbus_transport_do_iteration (transport=0x6bec70, flags=1, flags@entry=6, timeout_milliseconds=timeout_milliseconds@entry=25000)
    at ../../dbus/dbus-transport.c:1001
#5  0x00007ffd9214fc4c in _dbus_connection_do_iteration_unlocked (connection=connection@entry=0x6bfc30, pending=pending@entry=0x3c8d97e0, flags=flags@entry=6, 
    timeout_milliseconds=timeout_milliseconds@entry=25000) at ../../dbus/dbus-connection.c:1227
#6  0x00007ffd921505f9 in _dbus_connection_block_pending_call (pending=0x3c8d97e0) at ../../dbus/dbus-connection.c:2432
#7  0x00007ffd9a23dce7 in q_dbus_pending_call_block (pending=<optimized out>) at qdbus_symbols_p.h:309
#8  QDBusConnectionPrivate::waitForFinished (this=0x6beef0, pcall=pcall@entry=0x3a759f30) at qdbusintegrator.cpp:1780
#9  0x00007ffd9a27c97c in QDBusPendingCallPrivate::waitForFinished (this=0x3a759f30) at qdbuspendingcall.cpp:245
#10 0x00007ffd9a27caed in QDBusPendingCall::waitForFinished (this=this@entry=0x7fff8dc0dab0) at qdbuspendingcall.cpp:336
#11 0x00007ffd9749e097 in operator= (pcall=..., this=0x7fff8dc0dad0) at /usr/include/qt4/QtDBus/qdbusreply.h:88
---Type <return> to continue, or q <return> to quit---
#12 QDBusReply (reply=..., this=0x7fff8dc0dad0) at /usr/include/qt4/QtDBus/qdbusreply.h:93
#13 MailCommon::FolderCollection::identity (this=0x1313db0) at ../../mailcommon/folder/foldercollection.cpp:299
#14 0x00007ffd9d803792 in CollectionStorageModel::isOutBoundFolder (this=<optimized out>, c=...) at ../../kmail/widgets/collectionpane.cpp:70
#15 0x00007ffd97a8677f in MessageList::StorageModel::containsOutboundMessages (this=0x134b760) at ../../messagelist/storagemodel.cpp:218
#16 0x00007ffd97a3e76d in MessageList::Core::ModelPrivate::slotStorageModelHeaderDataChanged (this=0xd66660) at ../../messagelist/core/model.cpp:4476
#17 0x00007ffd9c7666aa in QMetaObject::activate (sender=0x134b760, m=m@entry=0x7ffd9cab66a0 <QAbstractItemModel::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7fff8dc0dea0) at kernel/qobject.cpp:3567
#18 0x00007ffd9c7b038d in QAbstractItemModel::headerDataChanged (this=<optimized out>, _t1=_t1@entry=Qt::Horizontal, _t2=_t2@entry=0, _t3=0)
    at .moc/release-shared/moc_qabstractitemmodel.cpp:170
#19 0x00007ffd97a85c6a in MessageList::StorageModel::Private::onSelectionChanged (this=0x14a294b0) at ../../messagelist/storagemodel.cpp:453
#20 0x00007ffd9c7666aa in QMetaObject::activate (sender=sender@entry=0xafb020, m=m@entry=0x7ffd9d7433a0 <QItemSelectionModel::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff8dc0e000) at kernel/qobject.cpp:3567
#21 0x00007ffd9d1c7ff7 in QItemSelectionModel::selectionChanged (this=this@entry=0xafb020, _t1=..., _t2=...) at .moc/release-shared/moc_qitemselectionmodel.cpp:165
#22 0x00007ffd9d1cd651 in QItemSelectionModel::emitSelectionChanged (this=this@entry=0xafb020, newSelection=..., oldSelection=...)
    at itemviews/qitemselectionmodel.cpp:1544
#23 0x00007ffd9d1cde23 in QItemSelectionModel::select (this=this@entry=0xafb020, selection=..., command=...) at itemviews/qitemselectionmodel.cpp:1110
#24 0x00007ffd97a827e3 in MessageList::Pane::Private::onSelectionChanged (this=0xd0f1a0, selected=..., deselected=...) at ../../messagelist/pane.cpp:457
#25 0x00007ffd9c7666aa in QMetaObject::activate (sender=sender@entry=0xaa6ea0, m=m@entry=0x7ffd9d7433a0 <QItemSelectionModel::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff8dc0e4d0) at kernel/qobject.cpp:3567
#26 0x00007ffd9d1c7ff7 in QItemSelectionModel::selectionChanged (this=this@entry=0xaa6ea0, _t1=..., _t2=...) at .moc/release-shared/moc_qitemselectionmodel.cpp:165
#27 0x00007ffd9d1cd651 in QItemSelectionModel::emitSelectionChanged (this=this@entry=0xaa6ea0, newSelection=..., oldSelection=...)
    at itemviews/qitemselectionmodel.cpp:1544
#28 0x00007ffd9d1cde23 in QItemSelectionModel::select (this=0xaa6ea0, selection=..., command=...) at itemviews/qitemselectionmodel.cpp:1110
#29 0x00007ffd9d1b9e1a in QTreeViewPrivate::select (this=this@entry=0xc79b60, topIndex=..., bottomIndex=..., command=...) at itemviews/qtreeview.cpp:3683
#30 0x00007ffd9d1ba71c in QTreeView::setSelection (this=<optimized out>, rect=..., command=...) at itemviews/qtreeview.cpp:2293
#31 0x00007ffd9d17a4fa in QAbstractItemView::mousePressEvent (this=0xa5af50, event=<optimized out>) at itemviews/qabstractitemview.cpp:1690
#32 0x00007ffd9ccd1b3b in QWidget::event (this=this@entry=0xa5af50, event=event@entry=0x7fff8dc0f300) at kernel/qwidget.cpp:8385
#33 0x00007ffd9d07043e in QFrame::event (this=0xa5af50, e=0x7fff8dc0f300) at widgets/qframe.cpp:557
#34 0x00007ffd9d17fd13 in QAbstractItemView::viewportEvent (this=this@entry=0xa5af50, event=event@entry=0x7fff8dc0f300) at itemviews/qabstractitemview.cpp:1644
#35 0x00007ffd9d1be930 in QTreeView::viewportEvent (this=0xa5af50, event=0x7fff8dc0f300) at itemviews/qtreeview.cpp:1252
#36 0x00007ffd9c752586 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=this@entry=0x6e6cc0, receiver=receiver@entry=0xa5a4b0, 
    event=event@entry=0x7fff8dc0f300) at kernel/qcoreapplication.cpp:1063
#37 0x00007ffd9cc826ac in QApplicationPrivate::notify_helper (this=this@entry=0x6e6cc0, receiver=receiver@entry=0xa5a4b0, e=e@entry=0x7fff8dc0f300)
    at kernel/qapplication.cpp:4566
#38 0x00007ffd9cc88e3a in QApplication::notify (this=this@entry=0x7fff8dc0fdf0, receiver=receiver@entry=0xa5a4b0, e=e@entry=0x7fff8dc0f300)
    at kernel/qapplication.cpp:4113
#39 0x00007ffd9e4ef76a in KApplication::notify (this=0x7fff8dc0fdf0, receiver=0xa5a4b0, event=0x7fff8dc0f300) at ../../kdeui/kernel/kapplication.cpp:311
#40 0x00007ffd9c75241d in QCoreApplication::notifyInternal (this=0x7fff8dc0fdf0, receiver=receiver@entry=0xa5a4b0, event=event@entry=0x7fff8dc0f300)
    at kernel/qcoreapplication.cpp:953
#41 0x00007ffd9cc88633 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#42 QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0xa5a4b0, event=event@entry=0x7fff8dc0f300, alienWidget=alienWidget@entry=0x0, 
    nativeWidget=nativeWidget@entry=0xa5a4b0, buttonDown=buttonDown@entry=0x7ffd9d7612d8 <qt_button_down>, lastMouseReceiver=..., spontaneous=spontaneous@entry=true)
    at kernel/qapplication.cpp:3178
#43 0x00007ffd9ccfa33b in QETWidget::translateMouseEvent (this=this@entry=0xa5a4b0, event=event@entry=0x7fff8dc0f670) at kernel/qapplication_x11.cpp:4540
#44 0x00007ffd9ccf8dac in QApplication::x11ProcessEvent (this=0x7fff8dc0fdf0, event=event@entry=0x7fff8dc0f670) at kernel/qapplication_x11.cpp:3663
---Type <return> to continue, or q <return> to quit---
#45 0x00007ffd9cd20712 in x11EventSourceDispatch (s=0x6e8200, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#46 0x00007ffd9352ee04 in g_main_dispatch (context=0x6e7060) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3064
#47 g_main_context_dispatch (context=context@entry=0x6e7060) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3663
#48 0x00007ffd9352f048 in g_main_context_iterate (context=context@entry=0x6e7060, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3734
#49 0x00007ffd9352f0ec in g_main_context_iteration (context=0x6e7060, may_block=1) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3795
#50 0x00007ffd9c77f655 in QEventDispatcherGlib::processEvents (this=0x66dad0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#51 0x00007ffd9cd207c6 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#52 0x00007ffd9c750fef in QEventLoop::processEvents (this=this@entry=0x7fff8dc0fa40, flags=...) at kernel/qeventloop.cpp:149
#53 0x00007ffd9c7512e5 in QEventLoop::exec (this=this@entry=0x7fff8dc0fa40, flags=...) at kernel/qeventloop.cpp:204
#54 0x00007ffd9c756ab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#55 0x00007ffd9cc80e8c in QApplication::exec () at kernel/qapplication.cpp:3828
#56 0x0000000000402d1a in main (argc=<optimized out>, argv=<optimized out>) at ../../kmail/main.cpp:146
(gdb)
Comment 6 Martin Steigerwald 2014-05-02 10:59:51 UTC 
Here another one during runtime of Akonadi. I found another way to reliably reproduce this:

- download new mails via POP3 resource
- filter them

Also killing the akonadi maildir resource process will make KMail respond immediately. I can do this some times, until KMail complains it is not working probably and marks all folders in red. Then I have to restart the resource manually. I bet thats a endless restart prevention thing.

(gdb) continue
Continuing.
[New Thread 0x7fce814de700 (LWP 26873)]
[New Thread 0x7fce8297e700 (LWP 26874)]
[New Thread 0x7fce33080700 (LWP 26888)]
[New Thread 0x7fce31514700 (LWP 26889)]
[Thread 0x7fce31514700 (LWP 26889) exited]
[New Thread 0x7fce31514700 (LWP 26892)]
[Thread 0x7fce31514700 (LWP 26892) exited]
^C
Program received signal SIGINT, Interrupt.
0x00007fceab2a68ed in poll () at ../sysdeps/unix/syscall-template.S:81
81      in ../sysdeps/unix/syscall-template.S
(gdb) t a a bt

Thread 7 (Thread 0x7fce33080700 (LWP 26888)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:238
#1  0x00007fceabb12784 in wait (time=30000, this=0x2de9120) at thread/qwaitcondition_unix.cpp:84
#2  QWaitCondition::wait (this=this@entry=0x2b3bd80, mutex=mutex@entry=0x2312e68, time=30000) at thread/qwaitcondition_unix.cpp:158
#3  0x00007fceabb0608a in QThreadPoolThread::run (this=0x2b3bd70) at concurrent/qthreadpool.cpp:142
#4  0x00007fceabb122bf in QThreadPrivate::start (arg=0x2b3bd70) at thread/qthread_unix.cpp:349
#5  0x00007fcea8b81062 in start_thread (arg=0x7fce33080700) at pthread_create.c:312
#6  0x00007fceab2b1bfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 6 (Thread 0x7fce8297e700 (LWP 26874)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:238
#1  0x00007fceabb12784 in wait (time=30000, this=0x2c4a3d0) at thread/qwaitcondition_unix.cpp:84
#2  QWaitCondition::wait (this=this@entry=0x2734450, mutex=mutex@entry=0x2c4a2b8, time=30000) at thread/qwaitcondition_unix.cpp:158
#3  0x00007fceabb0608a in QThreadPoolThread::run (this=0x2734440) at concurrent/qthreadpool.cpp:142
#4  0x00007fceabb122bf in QThreadPrivate::start (arg=0x2734440) at thread/qthread_unix.cpp:349
#5  0x00007fcea8b81062 in start_thread (arg=0x7fce8297e700) at pthread_create.c:312
#6  0x00007fceab2b1bfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 5 (Thread 0x7fce814de700 (LWP 26873)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:238
#1  0x00007fceabb12784 in wait (time=30000, this=0x22c8080) at thread/qwaitcondition_unix.cpp:84
#2  QWaitCondition::wait (this=this@entry=0x22c8b60, mutex=mutex@entry=0x22b5fa8, time=30000) at thread/qwaitcondition_unix.cpp:158
#3  0x00007fceabb0608a in QThreadPoolThread::run (this=0x22c8b50) at concurrent/qthreadpool.cpp:142
#4  0x00007fceabb122bf in QThreadPrivate::start (arg=0x22c8b50) at thread/qthread_unix.cpp:349
#5  0x00007fcea8b81062 in start_thread (arg=0x7fce814de700) at pthread_create.c:312
#6  0x00007fceab2b1bfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 4 (Thread 0x7fce89417700 (LWP 9564)):
#0  0x00007fceab2aadf3 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fceabbf10b1 in QProcessManager::run (this=0x7fceabf7b540 <processManager()::processManager>) at io/qprocess_unix.cpp:270
#2  0x00007fceabb122bf in QThreadPrivate::start (arg=0x7fceabf7b540 <processManager()::processManager>) at thread/qthread_unix.cpp:349
#3  0x00007fcea8b81062 in start_thread (arg=0x7fce89417700) at pthread_create.c:312
#4  0x00007fceab2b1bfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 3 (Thread 0x7fce83fff700 (LWP 9567)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fce9ed927d2 in WTF::TCMalloc_PageHeap::scavengerThread (this=<optimized out>) at wtf/FastMalloc.cpp:2499
#2  0x00007fce9ed92809 in WTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at wtf/FastMalloc.cpp:1622
#3  0x00007fcea8b81062 in start_thread (arg=0x7fce83fff700) at pthread_create.c:312
#4  0x00007fceab2b1bfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 2 (Thread 0x7fce837fe700 (LWP 9568)):
#0  0x00007fceab2a68ed in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fcea29f0fe4 in g_main_context_poll (priority=2147483647, n_fds=1, fds=0x7fce7c003080, timeout=9999, context=0x7fce7c0009a0)
---Type <return> to continue, or q <return> to quit---
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:4028
#2  g_main_context_iterate (context=context@entry=0x7fce7c0009a0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3729
#3  0x00007fcea29f10ec in g_main_context_iteration (context=0x7fce7c0009a0, may_block=1) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3795
#4  0x00007fceabc41676 in QEventDispatcherGlib::processEvents (this=0x7fce7c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:427
#5  0x00007fceabc12fef in QEventLoop::processEvents (this=this@entry=0x7fce837fdce0, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007fceabc132e5 in QEventLoop::exec (this=this@entry=0x7fce837fdce0, flags=...) at kernel/qeventloop.cpp:204
#7  0x00007fceabb0fbef in QThread::exec (this=<optimized out>) at thread/qthread.cpp:538
#8  0x00007fceabb122bf in QThreadPrivate::start (arg=0x21442a0) at thread/qthread_unix.cpp:349
#9  0x00007fcea8b81062 in start_thread (arg=0x7fce837fe700) at pthread_create.c:312
#10 0x00007fceab2b1bfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 1 (Thread 0x7fceadf7c900 (LWP 9561)):
#0  0x00007fceab2a68ed in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fcea162ea08 in poll (__timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:46
#2  _dbus_poll (fds=<optimized out>, n_fds=<optimized out>, timeout_milliseconds=<optimized out>) at ../../dbus/dbus-sysdeps-unix.c:2558
#3  0x00007fcea16285f8 in socket_do_iteration (transport=0x1a08c70, flags=6, timeout_milliseconds=<optimized out>) at ../../dbus/dbus-transport-socket.c:1117
#4  0x00007fcea162759f in _dbus_transport_do_iteration (transport=0x1a08c70, flags=1, flags@entry=6, timeout_milliseconds=timeout_milliseconds@entry=25000)
    at ../../dbus/dbus-transport.c:1001
#5  0x00007fcea1611c4c in _dbus_connection_do_iteration_unlocked (connection=connection@entry=0x1a09c30, pending=pending@entry=0x49d5530, flags=flags@entry=6, 
    timeout_milliseconds=timeout_milliseconds@entry=25000) at ../../dbus/dbus-connection.c:1227
#6  0x00007fcea16125f9 in _dbus_connection_block_pending_call (pending=0x49d5530) at ../../dbus/dbus-connection.c:2432
#7  0x00007fcea96ffce7 in q_dbus_pending_call_block (pending=<optimized out>) at qdbus_symbols_p.h:309
#8  QDBusConnectionPrivate::waitForFinished (this=0x1a08ef0, pcall=pcall@entry=0xb816ea0) at qdbusintegrator.cpp:1780
#9  0x00007fcea973e97c in QDBusPendingCallPrivate::waitForFinished (this=0xb816ea0) at qdbuspendingcall.cpp:245
#10 0x00007fcea973eaed in QDBusPendingCall::waitForFinished (this=this@entry=0x7fffb2c10a60) at qdbuspendingcall.cpp:336
#11 0x00007fcea6960097 in operator= (pcall=..., this=0x7fffb2c10a80) at /usr/include/qt4/QtDBus/qdbusreply.h:88
#12 QDBusReply (reply=..., this=0x7fffb2c10a80) at /usr/include/qt4/QtDBus/qdbusreply.h:93
#13 MailCommon::FolderCollection::identity (this=0x26f5d80) at ../../mailcommon/folder/foldercollection.cpp:299
#14 0x00007fceaccc5792 in CollectionStorageModel::isOutBoundFolder (this=<optimized out>, c=...) at ../../kmail/widgets/collectionpane.cpp:70
#15 0x00007fcea6f4877f in MessageList::StorageModel::containsOutboundMessages (this=0x940dba0) at ../../messagelist/storagemodel.cpp:218
#16 0x00007fcea6f0076d in MessageList::Core::ModelPrivate::slotStorageModelHeaderDataChanged (this=0x20b2720) at ../../messagelist/core/model.cpp:4476
#17 0x00007fceabc286aa in QMetaObject::activate (sender=0x940dba0, m=m@entry=0x7fceabf786a0 <QAbstractItemModel::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7fffb2c10e50) at kernel/qobject.cpp:3567
#18 0x00007fceabc7238d in QAbstractItemModel::headerDataChanged (this=<optimized out>, _t1=_t1@entry=Qt::Horizontal, _t2=_t2@entry=0, _t3=0)
    at .moc/release-shared/moc_qabstractitemmodel.cpp:170
#19 0x00007fcea6f47c6a in MessageList::StorageModel::Private::onSelectionChanged (this=0xfda0550) at ../../messagelist/storagemodel.cpp:453
#20 0x00007fceabc286aa in QMetaObject::activate (sender=sender@entry=0x20cfca0, m=m@entry=0x7fceacc053a0 <QItemSelectionModel::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fffb2c10fb0) at kernel/qobject.cpp:3567
#21 0x00007fceac689ff7 in QItemSelectionModel::selectionChanged (this=this@entry=0x20cfca0, _t1=..., _t2=...) at .moc/release-shared/moc_qitemselectionmodel.cpp:165
#22 0x00007fceac68f651 in QItemSelectionModel::emitSelectionChanged (this=this@entry=0x20cfca0, newSelection=..., oldSelection=...)
    at itemviews/qitemselectionmodel.cpp:1544
#23 0x00007fceac68fe23 in QItemSelectionModel::select (this=this@entry=0x20cfca0, selection=..., command=...) at itemviews/qitemselectionmodel.cpp:1110
#24 0x00007fcea6f447e3 in MessageList::Pane::Private::onSelectionChanged (this=0x205fc20, selected=..., deselected=...) at ../../messagelist/pane.cpp:457
#25 0x00007fceabc286aa in QMetaObject::activate (sender=sender@entry=0x2086130, m=m@entry=0x7fceacc053a0 <QItemSelectionModel::staticMetaObject>, 
---Type <return> to continue, or q <return> to quit---
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fffb2c11480) at kernel/qobject.cpp:3567
#26 0x00007fceac689ff7 in QItemSelectionModel::selectionChanged (this=this@entry=0x2086130, _t1=..., _t2=...) at .moc/release-shared/moc_qitemselectionmodel.cpp:165
#27 0x00007fceac68f617 in QItemSelectionModel::emitSelectionChanged (this=this@entry=0x2086130, newSelection=..., oldSelection=...)
    at itemviews/qitemselectionmodel.cpp:1600
#28 0x00007fceac68fe23 in QItemSelectionModel::select (this=0x2086130, selection=..., command=...) at itemviews/qitemselectionmodel.cpp:1110
#29 0x00007fceac67be1a in QTreeViewPrivate::select (this=this@entry=0x1fb5d50, topIndex=..., bottomIndex=..., command=...) at itemviews/qtreeview.cpp:3683
#30 0x00007fceac67c71c in QTreeView::setSelection (this=<optimized out>, rect=..., command=...) at itemviews/qtreeview.cpp:2293
#31 0x00007fceac63c4fa in QAbstractItemView::mousePressEvent (this=0x1da7a80, event=<optimized out>) at itemviews/qabstractitemview.cpp:1690
#32 0x00007fceac193b3b in QWidget::event (this=this@entry=0x1da7a80, event=event@entry=0x7fffb2c122b0) at kernel/qwidget.cpp:8385
#33 0x00007fceac53243e in QFrame::event (this=0x1da7a80, e=0x7fffb2c122b0) at widgets/qframe.cpp:557
#34 0x00007fceac641d13 in QAbstractItemView::viewportEvent (this=this@entry=0x1da7a80, event=event@entry=0x7fffb2c122b0) at itemviews/qabstractitemview.cpp:1644
#35 0x00007fceac680930 in QTreeView::viewportEvent (this=0x1da7a80, event=0x7fffb2c122b0) at itemviews/qtreeview.cpp:1252
#36 0x00007fceabc14586 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=this@entry=0x1a30d40, receiver=receiver@entry=0x1ce40e0, 
    event=event@entry=0x7fffb2c122b0) at kernel/qcoreapplication.cpp:1063
#37 0x00007fceac1446ac in QApplicationPrivate::notify_helper (this=this@entry=0x1a30d40, receiver=receiver@entry=0x1ce40e0, e=e@entry=0x7fffb2c122b0)
    at kernel/qapplication.cpp:4566
#38 0x00007fceac14ae3a in QApplication::notify (this=this@entry=0x7fffb2c12da0, receiver=receiver@entry=0x1ce40e0, e=e@entry=0x7fffb2c122b0)
    at kernel/qapplication.cpp:4113
#39 0x00007fcead9b176a in KApplication::notify (this=0x7fffb2c12da0, receiver=0x1ce40e0, event=0x7fffb2c122b0) at ../../kdeui/kernel/kapplication.cpp:311
#40 0x00007fceabc1441d in QCoreApplication::notifyInternal (this=0x7fffb2c12da0, receiver=receiver@entry=0x1ce40e0, event=event@entry=0x7fffb2c122b0)
    at kernel/qcoreapplication.cpp:953
#41 0x00007fceac14a633 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#42 QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0x1ce40e0, event=event@entry=0x7fffb2c122b0, alienWidget=alienWidget@entry=0x0, 
    nativeWidget=nativeWidget@entry=0x1ce40e0, buttonDown=buttonDown@entry=0x7fceacc232d8 <qt_button_down>, lastMouseReceiver=..., spontaneous=spontaneous@entry=true)
    at kernel/qapplication.cpp:3178
#43 0x00007fceac1bc33b in QETWidget::translateMouseEvent (this=this@entry=0x1ce40e0, event=event@entry=0x7fffb2c12620) at kernel/qapplication_x11.cpp:4540
#44 0x00007fceac1badac in QApplication::x11ProcessEvent (this=0x7fffb2c12da0, event=event@entry=0x7fffb2c12620) at kernel/qapplication_x11.cpp:3663
#45 0x00007fceac1e2712 in x11EventSourceDispatch (s=0x1a32270, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#46 0x00007fcea29f0e04 in g_main_dispatch (context=0x1a31090) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3064
#47 g_main_context_dispatch (context=context@entry=0x1a31090) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3663
#48 0x00007fcea29f1048 in g_main_context_iterate (context=context@entry=0x1a31090, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3734
#49 0x00007fcea29f10ec in g_main_context_iteration (context=0x1a31090, may_block=1) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3795
#50 0x00007fceabc41655 in QEventDispatcherGlib::processEvents (this=0x19b7ad0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#51 0x00007fceac1e27c6 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#52 0x00007fceabc12fef in QEventLoop::processEvents (this=this@entry=0x7fffb2c129f0, flags=...) at kernel/qeventloop.cpp:149
#53 0x00007fceabc132e5 in QEventLoop::exec (this=this@entry=0x7fffb2c129f0, flags=...) at kernel/qeventloop.cpp:204
#54 0x00007fceabc18ab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#55 0x00007fceac142e8c in QApplication::exec () at kernel/qapplication.cpp:3828
#56 0x0000000000402d1a in main (argc=<optimized out>, argv=<optimized out>) at ../../kmail/main.cpp:146
(gdb) 
(gdb) 
(gdb) continue
Continuing.
Comment 7 Martin Steigerwald 2015-03-12 12:37:35 UTC 
I didn´t see this since quite some time, currently using Akonadi 1.13 current master with MySQL performance improvements by Dan and Millian, kdepimlibs and kdepim-runtime from 24th of February and KMail 4.14.2.

Thus closing.
Comment 8 Martin Steigerwald 2016-08-27 11:10:07 UTC 
Well, I closed this back then as it works for me as the folder synchronisation in the maildir case got much better by the performance improvements made by Dan and Millian. Yet, the issue is still there, I tested it on deleting 100-200 mails during mailfilter agent filtering mails to local maildir folders and triggering folder synchronisations. Akonadi postponed the deleting until after those few quite quick synchronisations were finished, but it easily took about 10 seconds, so that still introduces an delay.
Comment 9 Martin Steigerwald 2016-08-27 11:12:02 UTC 
Nope forget this. I made up a my mind. Thats no blockage on switching folders and I don´t have this anymore. So… I make another bug report about folder synchronisation blocking other operations. Sorry for noise.