From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: long latency of domain shutdown
Date: Fri, 09 May 2008 11:29:02 +0100
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References: <48244234.76E4.0078.0@novell.com>
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To: Jan Beulich <jbeulich@novell.com>
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On 9/5/08 11:23, "Jan Beulich" <jbeulich@novell.com> wrote:

> Indeed, the extended version below avoids this.
> 
>> In actuality, since we know that we never have 'cross-domain' pagetable type
>> references, we should actually be able to zap pagetable reference counts to
>> zero. The only reason we don't do that right now is really because it
>> provides good debugging info to see whether a domain's refcounts have got
>> screwed up. But that would not prevent us doing something faster for NDEBUG
>> builds, at least.
> 
> I still thought it'd be better to not simply zap the counts, but
> incrementally drop them using the proper interface:

Theoretically you can still race PIN_Lx_TABLE hypercalls from other dom0
VCPUs. Obviously that would only happen from a misbehaving dom0 though. I
think this patch is a reasonable stopgap measure.

 -- Keir