[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-users] Correct Syntax for VCPU-Pinning

Hi all,

today I have wanted to do hard vcpu pinning from the domU config file
and found life still does *all* it can to stay challenging.

Take a VM with 2 vcpus that should be hard-pinned to two physical CPUs.
We'll use one core and one HT for this experiment.

One might try the following config.
vcpus = 2
cpus = [ "1", "5" ]

But this is in fact wrong. As we can see from xm vcpu-list this will
define two vcpus which are both runnable on cpu 1 or 5.

myvm                           29     0     5   r--      16.2 1,5
myvm                           29     1     5   ---      13.9 1,5

Whereas a
xm vcpu-pin myvm 0 1
xm vcpu-pin myvm 0 5

in fact does the right thing

myvm                           29     0     1   -b-      20.5 1
myvm                           29     1     5   -b-      18.6 5

in xm list --long this is presented as following format:
    (cpus (1 5))
And that entry doesn't change when I do the hard pinning.

So, is this in fact impossble to specify from a domU config file?


the purpose of libvirt is to provide an abstraction layer hiding all
xen features added since 2006 until they were finally understood and
copied by the kvm devs.

Xen-users mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.