Re: amd64 MP (was Re: pae MP on cherry-xenmp)

[David Howland <metalliqaz%fastmail.fm@localhost>]

On 10/12/2011 8:13 PM, Jean-Yves Migeon wrote:
> On 13.10.2011 01:46, David Howland wrote:
> > The 'time' column for the NetBSD domain counts up every second even
> > though 'top' in netbsd-51 shows both CPU's as 100% idle. Basically, what
> > you are seeing is a timer of how long the domain has been running since
> > I created it.
> >
> > I don't know what this means, but I report it because it seems to be
> > different from all the other OS in the list.
>
> Without looking at the code, I would say that the idle() loop for a CPU
> does not yield to hypervisor correctly. Or that something keeps kicking
> vCPUs out of it.

I replaced Cherry's kernel with a standard -current kernel (non-MP) and 
the problem goes away...

root@rackable:/etc/xen# xm list
Name               ID   Mem VCPUs      State   Time(s)
Domain-0            0  7178     4     r----- 476622.8
centos-57           5  2048     2     -b----   1411.3
netbsd-51           7  2048     1     -b----    108.4
solaris-11          4  2048     2     -b----   4589.1
windows-2008r2      8  4096     4     -b----     35.5

NetBSD seems to be able to idle just fine.

-d