Re: Linux 3.13: BUG: soft lockup - CPU#1 stuck for 22s! [qemu-kvm:2653]

["Jason S. Wagner" <jasonswagner@gmail.com>]

I didn't end up with any time to investigate this issue further due to 
Life Stuff.  I've just returned from vacation and upgraded all the 
software on my system.  I noticed I got a new version of spice and 
allowed an new kernel.  

Just wanted to report that everything seems fine now.

On Wed, Mar 12, 2014 at 12:38 PM, Jason S. Wagner 
<jasonswagner@gmail.com> wrote:
> Hi Paolo,
> 
> Hmm, the symptoms don't seem to match entirely -- I already am on a 
> 64-bit kernel.  I didn't recognize high CPU utilization, but I also 
> admit I wasn't looking for it.  Leaving the instance running doesn't 
> eventually hang my system, but it did cause strange system behavior.
> 
> Some apps would stall while launching, others that were already 
> running would not be able to perform some operations.  Nautilus, for 
> example, couldn't render directory views and would display 
> "Loading..." in the corner of the window.  I assume this is because 
> CPU1 is locked by KVM.  Stopping the instance would allow any pending 
> operations to complete; apps stuck launching all started at once, and 
> Nautilus was again able to show me my local disk.
> 
> I believe it also prevented clean shutdown.  My keyboard's LEDs would 
> stop responding and after allowing a reasonable amount of time, I 
> reached for the reset button several times.
> 
> I'll reinstall Linux 3.13 tonight and try to confirm these details.
> 
> On Wed, Mar 12, 2014 at 7:08 AM, Paolo Bonzini <pbonzini@redhat.com> 
> wrote:
>> Il 11/03/2014 21:01, Jason S. Wagner ha scritto:
>>> Hi all,
>>> 
>>> Over the weekend, Linux 3.13.6 was installed on my machine. When I
>>> started gnome-boxes on Monday morning, my VM halted during boot. 
>>> Only a
>>> portion of the VESA BIOS init output was displayed on-screen before 
>>> the
>>> halt. Backtraces occasionally appeared in dmesg
>>> (http://pastebin.com/uUiNLmJ6). Some other programs were prevented 
>>> from
>>> performing some tasks while the VM was running.
>>> 
>>> While investigating, I was directed to an earlier KVM bug report
>>> (https://lkml.org/lkml/2014/2/11/487). I downgraded to Linux 3.12.9 
>>> and
>>> rebooted, and now my VM is starting. Unfortunately, I'm very new to
>>> Linux, so I'm not sure what the next steps would be.
>> 
>> Yeah, it's quite likely this is the issue you're facing.
>> 
>> And the author of the report at 
>> http://www.spinics.net/lists/kvm/msg100196.html also told me 
>> privately that 64-bit kernel made it go away, so it's also likely to 
>> be the same thing.  Thomas, do you also see a "soft lockup" message?
>> 
>> Paolo