Re: [Xen-ia64-devel] [PATCH 2/9] [P2M/VP step 1] xen: introduce P2M conversion

[Tristan Gingold <Tristan.Gingold@xxxxxxxx>]

Le Jeudi 27 Avril 2006 04:09, Isaku Yamahata a écrit :
> On Wed, Apr 26, 2006 at 05:16:21PM +0200, Tristan Gingold wrote:
> > why does domain_page_flush purge TC entries ?
> > These entries map virtual addr to mp addr.  If you remove a page from the
> > domain, the next access will be trapped.
>
> I feared the race between ia64_do_page_fault() and removing page.
> Smp isn't supported yet for now, it doesn't make sense yet.
> Actually I'm not sure and I felt some consideration is necessary
> so that I added the comment, "XXX SMP", there.
> Presumably xenLinux doesn't issue such a racy operation,
> but it is possible in theory.
>
>
>         cpu0                            cpu1
> ia64_do_page_fault()
>   translate_domain_pte()
>
>                                         removing page.
>
>   vcpu_itc_no_srlz()
>   // bang!
Correct.

Tristan.



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