Re: "xm vcpu-pin" error

[Andre Przywara <andre.przywara@amd.com>]

Huang2, Wei wrote:
> I saw a warning message when using "xm vcpu-pin" command on latest 
> xen-unstable tree.
>  
> ========
> # xm vcpu-pin 0 0 0
> Error: Cannot pin vcpu: 0 to cpu: [0] - list assignment index out of range
> Usage: xm vcpu-pin <Domain> <VCPU|all> <CPUs|all>
>  
> Set which CPUs a VCPU can use.
> ========
I have seen this before, this issue is on my list. The problem is only 
occurring on Dom0 repinning. After having done the actual 
xc.vcpu_setaffinity call in XendDomain.py:1426, xend wants to set an 
entry in the Python array: cpus[v] = cpumap. This array has not been 
properly allocated for Dom0, thus forcing an assignment to an empty 
list. This is more or less cosmetic as long as you only pin one VCPU, 
but pinning all (e.g. xm vcpu-pin 0 all 4-7) will stop after the first 
VCPU, so you have to use some kind of shell-for-loop workaround _and_ 
ignore the error message. I haven't found a proper way to fix this yet.

Regards,
Andre.


-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
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