Comment # 27 on bug 935086 from Uwe Geuder

(In reply to Uwe Geuder from comment #10)

Let me first correct one of my previous observations.

> 
> > Also, increase the log level via alt-sysrq-8 or 9 beforehand.
> 
> The log level seems to have no effect on SysRq-L SysRq-P, and SysRq-T. when
> the system hangs no information is shown even if the log level is 8 or 9.
> When the 
> system works, full information is show even if the log level is 0.
> 
> During the boot more messages are shown if log level is 9. But there is no
> additional message shortly before the system hangs at "Reached target Remote
> File system" as shown in the screen pictures before.
> 

This was incorrect. On this keyboard I need to use the keypad digits to make it
work, Alt-SysRq-KP_8 instead of Alt-SysRq-8. which I used before.

So the corrected information is: the kernel seems to be fully alive every time
when the system hangs. Obviously the log level was too low before.

Unfortunately task list information does by far not fit into the console
scrollback buffer. So I we need that I have find a way to increase the
scrollback buffer first.

Form the CPU state I can see that always 3 of my cores are in idle and the 4th
core is handing the SysRq. So this might look like a deadlock in user space.