kdm_greet using lots and lots of CPU

[Not sure of the protocol here: should I have posted to Bug 690? or sent this email?] 3.5.13 kdm_greet eats lots of CPU. I see this was marked as fixed (Bug 690) and looking at the source of Slavek's kdm-trinity, I'm using his ppa on wheezy so the version of kdm-trinity installed is 4:3.5.13-2debian0~pre26+7~wheezy, the patches for kgreeter.cpp and sakdlg.cc are in place... but the bug's still there. It seems worse when a remote display connects but also happens with just a display on the machine's console. This is happening on my little laptop test mule (Intel Core 2) and a larger 16 core server (AMD Opteron). A few observations: /tmp/ksocket-global exists and is mode 0644. Curiously it's owned by what appears to be a random user-id. If I stop kdm, remove the /tmp/ksocket-global directory and restart kdm it recreates ksocket-global mode 0644 but owned by user id 1000... as that's the uid for the kdm_greet process (eh? why is kdm_greet changing its process uid? kdm is running as root. can't even see setuid being used in the kfrontend code). /tmp/ksocket-global is an empty directory. An strace on kdm_greet shows the following loop: read(-1, 0xbfcdd300, 2048) = -1 EBADF (Bad file descriptor) recv(4, 0x993e5f0, 4096, 0) = -1 EAGAIN (Resource temporarily unavailable) nanosleep({0, 500000}, NULL) = 0 gettimeofday({1358766636, 578738}, NULL) = 0 recv(4, 0x993e5f0, 4096, 0) = -1 EAGAIN (Resource temporarily unavailable) gettimeofday({1358766636, 578825}, NULL) = 0 select(9, [4 5 8], [], [], {0, 0}) = 0 (Timeout) gettimeofday({1358766636, 578940}, NULL) = 0 read(-1, 0xbfcdd300, 2048) = -1 EBADF (Bad file descriptor) The read from -1 is obviously wrong. /var/log/kdm.log contains errors as follows: <fair enough: it doesn't exist> This file does exist mode 0644 uid root, gid root. /etc/qt3 is mode 0755, root.root /etc is 0711, root.root /tmp/1468675921/.qt does exist. Mode 0775, root.root. Nothing in there though. >QSettings::sync: failed to open '/etc/qt3/qt_plugins_3.3rc.tmp' for writing >QSettings::sync: failed to open '/etc/qt3/qt_plugins_3.3rc.tmp' for writing >QSettings::sync: failed to open '/etc/qt3/qt_plugins_3.3rc.tmp' for writing >QSettings::sync: failed to open '/etc/qt3/qt_plugins_3.3rc.tmp' for writing >QSettings::sync: failed to open '/etc/qt3/qt_plugins_3.3rc.tmp' for writing >QSettings::sync: failed to open '/etc/qt3/qt_plugins_3.3rc.tmp' for writing I'm very happy to test/debug/try code. Original Bug Ref: http://bugs.trinitydesktop.org/bugzilla/show_bug.cgi?id=690 -- Regards, Russell -------------------------------------------------------------------- | Russell Brown | MAIL: russell(a)lls.com PHONE: 01780 471800 | | Lady Lodge Systems | WWW Work: http://www.lls.com | | Peterborough, England | WWW Play: http://www.ruffle.me.uk | --------------------------------------------------------------------