[Crash-utility] linux_banner has garbage

[Dave Anderson]

----- Original Message -----
> Hello Dave,
>
> I got a kernel freeze yesterday and am able to successfully open the memory
> image using crash utility.
>
> crash> sys
>       KERNEL: ./usr/lib/debug/usr/lib/modules/4.14.19-coreos/vmlinux
>     DUMPFILE: gt-Server02-gmt-612746ca.vmss
>         CPUS: 70
>         DATE: Wed Feb 21 14:53:20 2018
>       UPTIME: 1 days, 11:52:25
> LOAD AVERAGE: 70.70, 30.98, 12.88
>        TASKS: 2312
>     NODENAME: gt-Server02-gmt.com
>      RELEASE: 4.14.19-coreos 
>      VERSION: #1 SMP Wed Feb 14 03:18:05 UTC 2018
>      MACHINE: x86_64  (2094 Mhz)
>       MEMORY: 60 GB
>        PANIC: ""
> crash>
>
> Could you please guide me about couple of things I should check in case of
> a kernel freeze before diving in deep to find the root cause ?

I'm not sure what you mean by a "kernel freeze", but typically something
would complain about a hard or soft lockup in the system log.  So I would 
first run "log" to see if there's anything of interest.  Run "bt -a" on 
the active tasks to see if the active tasks are contesting for something,
or work your way through "foreach bt" to see what the tasks of interest are 
doing/waiting on.  It would seem that some task has taken control of something,
a lock, or counter, or whatever, and many other tasks have blocked waiting
for its release.  So there's probably a common theme among the blocked tasks
that might give you a clue.  

Dave