On Thu, Dec 02, 2010 at 03:27:42PM -0600, W. Michael Petullo wrote:
> >> This kernel works as expected with one exception. The exception has been
> >> a nagging problem, but I have not reported it because 1) we are using
> >> a research OS in DomU and 2) we are not clear if the problem is in our
> >> code, Linux or Xen. But, here are the symptoms:
> >> Occasionally (this seems to correlate to network activity between Dom0
> >> and DomU), the system becomes unresponsive. I am running the Michael
> >> Young kernel at runlevel 3 within Dom0 (very little memory used by
> >> applications). Our OS runs in DomU and is constrained to 128MB of
> >> memory. When the system is unresponsive, typing a character into a
> >> Dom0 console take 2-5 seconds to appear on the screen. Likewise, other
> >> activity is extremely slow. As I mentioned, we have not been able to
> >> isolate where the problem is. Running, for example, an OpenWrt Linux
> >> build in DomU does not have this problem.
> > I have seen something similar, though I don't know where the fault
> > lies either.
> That is somewhat good to hear. I have today solved this problem by running
> "xm vcpu-set Domain-0 1." By default, Xen assigned Dom0 all of my cores
> (two). Reducing this to one solves the problem for me. I am working on
> a better write up that I'll send to fedora-xen and possibly the upstream
> Xen mailing list. I have not decided if this is a bug and am having some
> discussions locally that may help me formulate a better inquiry.
Usually it's better to use dom0_max_vcpus=1 on the grub xen.gz line.
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