Re: [dpdk-dev] kernel: BUG: soft lockup - CPU#1 stuck for 22s! [kni_single:1782]

[Jay Rolette <rolette@infiniteio.com>]

Thanks Alejandro.

I'll look into the kernel dump if there is one. The system is extremely
brittle once this happens. Usually I can't do much other than power-cycle
the box. Anything requiring sudo just locks the terminal up, so little to
look at besides the messages on the console.

Matthew Hall also suggested a few things for me to look into, so I'm
following up on that as well.

Jay

On Wed, Feb 11, 2015 at 10:25 AM, Alejandro Lucero <
alejandro.lucero@netronome.com> wrote:

> Hi Jay,
>
> I saw these errors when I worked in the HPC sector. They come usually with
> a kernel dump for each core in the machine so you can know, after some
> peering at the kernel code, how the soft lockup triggers. When I did that
> it was always an issue with the memory.
>
> So those times that you can still work on the machine after the problem,
> look at the kernel messages. I will be glad to look at it.
>
>
>
> On Wed, Feb 11, 2015 at 1:33 AM, Jay Rolette <rolette@infiniteio.com>
> wrote:
>
> > Environment:
> >   * DPDK 1.6.0r2
> >   * Ubuntu 14.04 LTS
> >   * kernel: 3.13.0-38-generic
> >
> > When we start exercising KNI a fair bit (transferring files across it,
> both
> > sending and receiving), I'm starting to see a fair bit of these kernel
> > lockups:
> >
> > kernel: BUG: soft lockup - CPU#1 stuck for 22s! [kni_single:1782]
> >
> > Frequently I can't do much other than get a screenshot of the error
> message
> > coming across the console session once we get into this state, so
> debugging
> > what is happening is "interesting"...
> >
> > I've seen this on multiple hardware platforms (so not box specific) as
> well
> > as virtual machines.
> >
> > Are there any known issues with KNI that would cause kernel lockups in
> DPDK
> > 1.6? Really hoping someone that knows KNI well can point me in the right
> > direction.
> >
> > KNI in the 1.8 tree is significantly different, so it didn't look
> > straight-forward to back-port it, although I do see a few changes that
> > might be relevant.
> >
> > Any suggestions, pointers or other general help for tracking this down?
> >
> > Thanks!
> > Jay
> >
>