Re: [PATCH 0/2] Quieten softlockup detector on virtualised kernels

[Andrew Morton]

On Mon, 22 Dec 2014 16:06:02 +1100 Cyril Bur <cyrilbur@xxxxxxxxx> wrote:

> When the hypervisor pauses a virtualised kernel the kernel will observe a jump
> in timebase, this can cause spurious messages from the softlockup detector.
> 
> Whilst these messages are harmless, they are accompanied with a stack trace
> which causes undue concern and more problematically the stack trace in the
> guest has nothing to do with the observed problem and can only be misleading.
> 
> Futhermore, on POWER8 this is completely avoidable with the introduction of
> the Virtual Time Base (VTB) register.

Does this problem apply to other KVM implementations and to Xen?  If
so, what would implementations of running_clock() for those look like? 
If not, why not?


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