Re: 4.4: INFO: rcu_sched self-detected stall on CPU

From: Steven Haigh
Date: Fri Mar 25 2016 - 17:07:24 EST


On 26/03/2016 3:20 AM, Boris Ostrovsky wrote:
> On 03/25/2016 12:04 PM, Steven Haigh wrote:
>> It may not actually be the full logs. Once the system gets really upset,
>> you can't run anything - as such, grabbing anything from dmesg is not
>> possible.
>>
>> The logs provided above is all that gets spat out to the syslog server.
>>
>> I'll try tinkering with a few things to see if I can get more output -
>> but right now, that's all I've been able to achieve. So far, my only
>> ideas are to remove the 'quiet' options from the kernel command line -
>> but I'm not sure how much that would help.
>>
>> Suggestions gladly accepted on this front.
>
> You probably want to run connected to guest serial console ("
> serial='pty' " in guest config file and something like 'loglevel=7
> console=tty0 console=ttyS0,38400n8' on guest kernel commandline). And
> start the guest with 'xl create -c <cfg>' or connect later with 'xl
> console <domainID>'.

Ok thanks, I've booted the DomU with:

$ cat /proc/cmdline
root=UUID=63ade949-ee67-4afb-8fe7-ecd96faa15e2 ro enforcemodulesig=1
selinux=0 fsck.repair=yes loglevel=7 console=tty0 console=ttyS0,38400n8

I've left a screen session attached to the console (via xl console) and
I'll see if that turns anything up. As this seems to be rather
unpredictable when it happens, it may take a day or two to get anything.
I just hope its more than the syslog output :)

--
Steven Haigh

Email: netwiz@xxxxxxxxx
Web: https://www.crc.id.au
Phone: (03) 9001 6090 - 0412 935 897

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