On Tue, 3 Jul 2007, Manuel Bouyer wrote:
> On Tue, Jul 03, 2007 at 03:15:09PM +0100, Stephen Borrill wrote:
>> On Sun, 3 Jun 2007, Manuel Bouyer wrote:
>>> On Thu, May 31, 2007 at 09:24:51AM +0100, Stephen Borrill wrote:
>>>> Every now and then I get reports of a customer's DomU running slowly and,
>>>> sure enough, when I connect it takes ages to login. However, it's running
>>>> at 100% idle and the other DomU on the same box is fine. A reboot of the
>>>> DomU fixes it. When it happened today, I saw the following on the Dom0
>>>> console (which is running quickly and responsively):
>>>>
>>>> xen_shm_map: ENOMEM
>>>> xen_shm_map: ENOMEM1
>>>> xvif3.0: can't map packet page
>>>>
>>>> The first two are debugging, I believe, but the third looks suspicious...
>>>>
>>>> The kernels are 3.1_STABLE from 20th Nov 2006. Have there been pullups
>>>> that fix this, i.e. should I be updating? I'm not in a position to upgrade
>>>> to NetBSD 4.0/Xen3 at the moment.
>>>
>>> You may have an usage that requires more VM space for inter-domains
>>> communications than is currenly allocated. You can try increasing
>>> XENSHM_NPAGES
>>> in sys/arch/xen/i386/xen_shm_machdep.c
>>
>> On the DOM0 presumably?
>
> Yes
>
>> Would doubling it be a fair increase?
>
> Yes, in fact it really depends on how much domUs will do a full ring of I/Os
> at the same time (or how much interfaces in a single domU)

I've doubled it and also now the domU is the only one on the box. The 
performance problems are still happening.

-- 
Stephen