On Mon, Oct 27, 2008 at 04:36:38PM +0800, Zhang, Xiantao wrote:
> Isaku Yamahata wrote:
> > On Fri, Oct 24, 2008 at 09:59:58AM +0800, Zhang, Jingke wrote:
> >> 3. IPF-Xen can not boot up domain with dom_id > 62 (not
> >> regression, should be there for a long time)
> > Long ago, I posted the patch to address this issue.
> > Probably there are two ways. (Is there other better way?)
> > a.) abandon the rid partitioning, and flush mTLB every time vcpu
> > context switch.
> Current kvm adopts this method, we didn't find any performance regression
> through benchmark. But sine the architecture difference between xen and kvm,
> so maybe should investigate more through enough benchmark data.
> > (some bits of rid space needs to be reserved for real mode
> > emulation.)
> > b.) keep the rid partitioning and allow rid collision.
> > When vcpu context switch, check the rid collision and
> > flush mTLB if necessary.
> > Benchmark would be necessary to decide which one is better and
> > to estimate performance degradation.
> > I implemented b). However no one has implemented a).
> > So no further step was taken.
> I thought Jingke isn't saying this topic. What he found maybe he failed to
> create the domain when the domain is created and destoryed continuously for
> more 62 times. Seems the issue is from the the algorithm for deallocating
> rid blocks doesn't work, when destroying the guest.
Oh I see. Thank you for the explanation.
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