System freeze (KDE? kernel?)

cfr · 2013-08-25 22:24:23

I am not sure where to post this as I am not certain what the problem is. My system just froze forcing hard shut down using the power button. The system did not respond in any way - ctrl + alt + backspace is enabled but was ignored; could not switch to vt etc. I did not try sys-rq key as it is not enabled.

The freeze occurred while I was Alt-tabbing between applications in KDE. Given the recent upgrades to KDE, some aspect of KDE might be the culprit - or might not.

The other major change is the update to the intel drivers which have switched me from uxa to sna acceleration. Don't know if I should switch back to uxa but I would like some idea if that might be the culprit before doing so.

The logs and journal are remarkably uninformative. I tried disconnecting the USB mouse and the power, as well as closing the laptop lid before I forced power off. In the journal, it looks as if the mouse change registered but neither of the others.

I use syslog in addition to journal.

/var/log/errors.log.1 ends with this:

Aug 24 22:41:49 localhost kdm: :0[1052]: pam_systemd(kde:session): Failed to connect to system bus: Failed to connect to socket /run/dbus/system_bus_socket: Connection refused
Aug 24 22:41:49 localhost kdm: :0[1052]: pam_close_session() failed: Cannot make/remove an entry for the specified session
Aug 24 22:42:29 localhost systemd-modules-load[240]: Failed to insert 'acpi_cpufreq': Device or resource busy
Aug 24 22:42:55 localhost bluetoothd[949]: Failed to init gatt_example plugin
Aug 24 22:42:57 localhost bluetoothd[949]: input-headset driver probe failed for device <uid probably not security sensitive but who knows?>
Aug 24 22:42:57 localhost bluetoothd[949]: Unknown command complete for opcode 19
Aug 24 22:42:57 localhost ntpd_intres[1599]: host name not found: 0.pool.ntp.org
Aug 24 22:42:57 localhost ntpd_intres[1599]: host name not found: 1.pool.ntp.org
Aug 24 22:42:57 localhost ntpd_intres[1599]: host name not found: 2.pool.ntp.org
Aug 24 22:43:06 localhost dhcpcd[1641]: dhcpcd not running
Aug 24 22:43:06 localhost dhcpcd[1647]: dhcpcd not running
Aug 24 22:43:06 localhost dhcpcd[1655]: dhcpcd not running

The modules-load error is normal and not a problem. (I'm using the intel_pstate stuff but have the acpi_cpufreq stuff still configured for if I boot LTS.) The bluetooth errors occur regularly and are therefore probably harmless.

The kdm errors look to me to be the only potential cause of trouble here. (I assume the ntpd and dhcpd errors are likely caused by the problem rather than causes of it.)

The relevant part of the journal:

Aws 25 22:46:53 MyComputer kernel: hub 2-1:1.0: port 1 disabled by hub (EMI?), re-enabling...
Aws 25 22:46:53 MyComputer kernel: usb 2-1.1: USB disconnect, device number 8
Aws 25 22:46:53 MyComputer kernel: usb 2-1.1: new low-speed USB device number 9 using ehci-pci
Aws 25 22:46:53 MyComputer laptop-mode[12031]: Laptop mode
Aws 25 22:46:53 MyComputer laptop-mode[12034]: enabled, not active
Aws 25 22:46:53 MyComputer laptop-mode[12054]: Laptop mode
Aws 25 22:46:53 MyComputer laptop-mode[12055]: enabled, not active
Aws 25 22:46:54 MyComputer kernel: input: Logitech USB-PS/2 Optical Mouse as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0/input/input18
Aws 25 22:46:54 MyComputer kernel: hid-generic 0003:046D:C00E.0006: input,hidraw0: USB HID v1.10 Mouse [Logitech USB-PS/2 Optical Mouse] on usb-0000:00:1d.0-1.1/input0
Aws 25 22:46:54 MyComputer mtp-probe[12071]: checking bus 2, device 9: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1"
Aws 25 22:46:54 MyComputer mtp-probe[12071]: bus: 2, device: 9 was not an MTP device
Aws 25 22:46:54 MyComputer laptop-mode[12120]: Laptop mode
Aws 25 22:46:54 MyComputer laptop-mode[12123]: enabled, not active
Aws 25 22:46:54 MyComputer laptop-mode[12143]: Laptop mode
Aws 25 22:46:54 MyComputer laptop-mode[12144]: enabled, not active

This is followed by some messages logged from iptables. Last message is 22:48:04.

Is there anything else I can check for clues or anything I should do about the kdm issue (if it really is a problem)?

karol · 2013-08-25 22:53:28

The only similar issue I run into recently is https://bugs.archlinux.org/task/36574

cfr · 2013-08-25 23:04:25

Thanks. That is not terribly similar although it is obviously hard to tell. I don't use zramswap and while I obviously don't know what my memory usage was just before the freeze, I have no reason to think it was particularly high. I have 8G of RAM , 9G of swap and I never, ever have seen usage of more than a tiny fraction of the swap. Mostly, I have a great deal of free memory. (Right now 6.1G of RAM is free and all 9G of swap.) I wasn't compiling code or fractals or anything similarly resource-intensive. I had kile and firefox open, together with konsole. That's about it. Nothing was actively running in konsole. While I have an enormous number of firefox tabs, the vast majority are unloaded and I was not loading an unknown site or anything similar. I don't think I was even compiling in kile.

cfr · 2013-08-25 23:51:02

Thinking about this some more it occurs to me that the following may be an incredibly dumb question: should I have rebooted after kmod was updated? Could not doing so have caused the freeze?

donniezazen · 2013-08-25 23:51:15

I have had freezes for as long as I am have been using 3.10.x. My system freezes at least once a day. I haven't had enough time to sit down and investigate the issue.

WonderWoofy · 2013-08-26 01:11:55

@cfr was this a one time occurance, or has it happened a number of times? If I were you I would turn on that sysrq button just in case. I like to always keep it on. If you don't want to enable all the functioanlity, you can enable bits and pieces of it. See /usr/src/linux-$(uname -r)/Documentation/sysrq.txt of the linux-docs package for specifics on what values you might want to set there.

cfr · 2013-08-26 01:15:01

One time. That's why I asked about updating kmod.

Hmm. I have enabled sysrq in the past and either I did it wrong or it did nothing whatsoever. Also, isn't it supposed to be a security problem? That's made me a bit nervous.

WonderWoofy · 2013-08-26 01:19:48

Wikipedia on Magic Sysrq wrote:

Some people view this key as giving access to dangerous system-level commands to anyone who has physical access to the keyboard or serial console.[8] It has been argued that this perceived security is illusory, as anyone with physical access to the computer would already have the capability to compromise its security.[9] The advent of the procfs interface has rekindled debate over this subject.

I agree with this that anyone who has physical access to the machine is a potential security risk. In your case, I think that giving the ability to reboot the machine is probably just fine since you use an encrypted system. They would essentially just be locking themselves out of the system.

If you want the sysrq setting to work, you need to either put it in /etc/sysctl.conf or in a /etc/sysctl.d/*.conf that will be lexicographically parsed before 50-default.conf. I just set mine to kernel.sysrq=1 in /etc/sysctl.d/00-custom.conf.

Arch Linux

#1 2013-08-25 22:24:23

System freeze (KDE? kernel?)

#2 2013-08-25 22:53:28

Re: System freeze (KDE? kernel?)

#3 2013-08-25 23:04:25

Re: System freeze (KDE? kernel?)

#4 2013-08-25 23:51:02

Re: System freeze (KDE? kernel?)

#5 2013-08-25 23:51:15

Re: System freeze (KDE? kernel?)

#6 2013-08-26 01:11:55

Re: System freeze (KDE? kernel?)

#7 2013-08-26 01:15:01

Re: System freeze (KDE? kernel?)

#8 2013-08-26 01:19:48

Re: System freeze (KDE? kernel?)

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