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* vsyscall support in 2.6.{32,33}
@ 2010-09-21 12:49 Paolo Bonzini
  2010-09-21 13:09 ` Pasi Kärkkäinen
  0 siblings, 1 reply; 3+ messages in thread
From: Paolo Bonzini @ 2010-09-21 12:49 UTC (permalink / raw)
  To: xen-devel@lists.xensource.com; +Cc: Drew Jones

Besides the obvious fact that the required hypercall is not supported by 
any released hypervisor, is there any other reason why the xen vsyscall 
code is not in the pvops/stable-2.6.{32,33}.x branches?

Thanks!

Paolo

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: vsyscall support in 2.6.{32,33}
  2010-09-21 12:49 vsyscall support in 2.6.{32,33} Paolo Bonzini
@ 2010-09-21 13:09 ` Pasi Kärkkäinen
  2010-09-21 17:31   ` Jeremy Fitzhardinge
  0 siblings, 1 reply; 3+ messages in thread
From: Pasi Kärkkäinen @ 2010-09-21 13:09 UTC (permalink / raw)
  To: Paolo Bonzini
  Cc: Drew Jones, xen-devel@lists.xensource.com, Jeremy Fitzhardinge

On Tue, Sep 21, 2010 at 02:49:17PM +0200, Paolo Bonzini wrote:
> Besides the obvious fact that the required hypercall is not supported by  
> any released hypervisor, is there any other reason why the xen vsyscall  
> code is not in the pvops/stable-2.6.{32,33}.x branches?
>
> Thanks!
>

I guess Jeremy didn't remember to merge it yet? :)
Or is there some problem with it?

-- Pasi

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: vsyscall support in 2.6.{32,33}
  2010-09-21 13:09 ` Pasi Kärkkäinen
@ 2010-09-21 17:31   ` Jeremy Fitzhardinge
  0 siblings, 0 replies; 3+ messages in thread
From: Jeremy Fitzhardinge @ 2010-09-21 17:31 UTC (permalink / raw)
  To: Pasi Kärkkäinen
  Cc: Paolo Bonzini, Drew Jones, xen-devel@lists.xensource.com

 On 09/21/2010 06:09 AM, Pasi Kärkkäinen wrote:
> On Tue, Sep 21, 2010 at 02:49:17PM +0200, Paolo Bonzini wrote:
>> Besides the obvious fact that the required hypercall is not supported by  
>> any released hypervisor, is there any other reason why the xen vsyscall  
>> code is not in the pvops/stable-2.6.{32,33}.x branches?
>>
>> Thanks!
>>
> I guess Jeremy didn't remember to merge it yet? :)
> Or is there some problem with it?
>

The main problem is that I'm not sure that the Xen clock algorithm can
give strict enough monotonicity for usermode use (ie, can't meet the
expected behaviour of clock_gettime()), and its not at all clear how to
fix it.  I could prevent non-monotonicity within one process, but not
between processes.

    J

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-09-21 17:31 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2010-09-21 12:49 vsyscall support in 2.6.{32,33} Paolo Bonzini
2010-09-21 13:09 ` Pasi Kärkkäinen
2010-09-21 17:31   ` Jeremy Fitzhardinge

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