Description of problem: Using Alt-Sysrq-k key combination while on X11 login screen will freeze machine / crash kernel (totally unresponsive system, blinking lights (laptop)). Using same sequence on the console works. Version-Release number of selected component (if applicable): 00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c) (prog-if 00 [VGA controller]) Subsystem: Lenovo T61 Flags: bus master, fast devsel, latency 0, IRQ 30 Memory at f8100000 (64-bit, non-prefetchable) [size=1M] Memory at e0000000 (64-bit, prefetchable) [size=256M] I/O ports at 1800 [size=8] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 3 Kernel driver in use: i915 Kernel modules: i915 How reproducible: Happens always. Steps to Reproduce: 1. Enable sysrq keys 2. boot with X11 3. on login screen, press alt-sysrq-k, machine will freeze Actual results: Machine freeze (crash), all lights are blinking. Needs hard reboot after that. Expected results: X11 restarts, new login screen apprears Additional info: I have tried these: https://fedoraproject.org/wiki/Common_F11_bugs#Miscellaneous_problems_with_Intel_graphics_adapters 1) nomodeset, no effect, machine still crashes 2) Option "AccelMethod" "EXA", no effect, machine still crashes
The system is up to date rawhide. Linux xxx 2.6.31.1-56.fc12.i686 #1 SMP Tue Sep 29 16:32:02 EDT 2009 i686 i686 i386 GNU/Linux
(In reply to comment #0) > 3. on login screen, press alt-sysrq-k, machine will freeze > > Actual results: > Machine freeze (crash), all lights are blinking. Needs hard reboot after that. > > > Expected results: > X11 restarts, new login screen apprears Doesn't alt-sysrq-k kill ALL processes (including init, and whatever underlies Xorg?). I am afraid you just got what you bargained for :). Closing as NOTABUG and feel free to reopen if you have some arguments to persuade me otherwise.
Hello Matej, sysrq-k should not kill all processes, just those which are associated to the current terminal. For example, it's called as linux SAK, but it's also handy in other situations. You can also try this by yourself, hitting sysrq-k on terminal (console), kills that terminal, and brings back a login prompt, and not killing everything on the machine. Also sysrq-k on X11 used to kill and restart gdm/kdm and brought back new instance of login screen. Now the machine hangs, and hence the bug report. Below is an quote from Kernel/Dokumentation/sysrq.txt: 'k' - Secure Access Key (SAK) Kills all programs on the current virtual console. NOTE: See important comments below in SAK section. sa'K' (Secure Access Key) is useful when you want to be sure there is no trojan program running at console which could grab your password when you would try to login. It will kill all programs on given console, thus letting you make sure that the login prompt you see is actually the one from init, not some trojan program. IMPORTANT: In its true form it is not a true SAK like the one in a :IMPORTANT IMPORTANT: c2 compliant system, and it should not be mistaken as :IMPORTANT IMPORTANT: such. :IMPORTANT It seems others find it useful as (System Attention Key) which is useful when you want to exit a program that will not let you switch consoles. (For example, X or a svgalib program.) http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.31.y.git;a=blob_plain;f=Documentation/sysrq.txt;hb=HEAD I will reopen this, based on my comments above. Best Regards, Jani
Not really sure whether its 100% related - but after SysRq+K you need to reintialize GPU. For this you might find hand this small shell script: --- #!/bin/sh setpci -s 00:02.0 0xc0.b=1 sleep 3 setpci -s 00:02.0 0xc0.b=0 modprobe -r i915 modprobe i915 vbetool post --- Obviously you need to login into console and run this script blind (thus some short name in $PATH is usefull - so you wont make a mistake). In my case I'll know in front, that I'll need this command, I prepare this just for pressing return on some of the consoles. Note - in standard case only 'vbetool post' could be enough.
Since this bugzilla report was filed, there have been several major updates in various components of the Xorg system, which may have resolved this issue. Users who have experienced this problem are encouraged to upgrade their system to the latest version of their packages (at least F12Beta, but even better if the very latest versions). Please, if you experience this problem on the up-to-date system, let us now in the comment for this bug, or whether the upgraded system works for you. If you won't be able to reply in one month, I will have to close this bug as INSUFFICIENT_DATA. Thank you. [This is a bulk message for all open Fedora Rawhide Xorg-related bugs. I'm adding myself to the CC list for each bug, so I'll see any comments you make after this and do my best to make sure every issue gets proper attention.]
This bug appears to have been reported against 'rawhide' during the Fedora 12 development cycle. Changing version to '12'. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
This bug still exists with up to date rawhide / F12. Also there is previous report against F10, plese see: https://bugzilla.redhat.com/show_bug.cgi?id=491474
*** This bug has been marked as a duplicate of bug 491474 ***