* A question about TLS libraries in case of Xen integration in Linux
@ 2006-02-21 15:42 Philippe Berthault
2006-02-21 16:59 ` Rik van Riel
0 siblings, 1 reply; 3+ messages in thread
From: Philippe Berthault @ 2006-02-21 15:42 UTC (permalink / raw)
To: Xen-Devel
The current Xen hypervisor (v3.0.1) doesn't support TLS library.
In case of an hypothetical integration of Xen in Linux and also in
distributions
such as RHEL5, SuSE, etc... this restriction becomes unacceptable.
So my question is:
There is a plan to support TLS library in the future or there is a plan
to integrate a Xen compatible TLS library in Linux ?
Philippe Berthault.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: A question about TLS libraries in case of Xen integration in Linux
2006-02-21 15:42 A question about TLS libraries in case of Xen integration in Linux Philippe Berthault
@ 2006-02-21 16:59 ` Rik van Riel
2006-02-22 14:09 ` Mark Williamson
0 siblings, 1 reply; 3+ messages in thread
From: Rik van Riel @ 2006-02-21 16:59 UTC (permalink / raw)
To: Philippe Berthault; +Cc: Xen-Devel
On Tue, 21 Feb 2006, Philippe Berthault wrote:
> The current Xen hypervisor (v3.0.1) doesn't support TLS library.
Are you sure? ISTR it just flipping the segment on every fault,
and incurring a slowdown.
> There is a plan to support TLS library in the future or there is a plan
> to integrate a Xen compatible TLS library in Linux ?
Fedora Core 4 and 5 have such a glibc variant. Other distributions
may have it too.
--
All Rights Reversed
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: A question about TLS libraries in case of Xen integration in Linux
2006-02-21 16:59 ` Rik van Riel
@ 2006-02-22 14:09 ` Mark Williamson
0 siblings, 0 replies; 3+ messages in thread
From: Mark Williamson @ 2006-02-22 14:09 UTC (permalink / raw)
To: xen-devel; +Cc: Philippe Berthault
Sorry if this was already replied to by someone...
> > The current Xen hypervisor (v3.0.1) doesn't support TLS library.
>
> Are you sure? ISTR it just flipping the segment on every fault,
> and incurring a slowdown.
Yep.
> > There is a plan to support TLS library in the future or there is a plan
> > to integrate a Xen compatible TLS library in Linux ?
>
> Fedora Core 4 and 5 have such a glibc variant. Other distributions
> may have it too.
Fedora's glibc switches off the TLS negative segment accesses (and uses
conventional accesses) when running on Xen. SuSE's glibc variant just
doesn't implement TLS accesses using negative segment offsets on any system,
so it also supports Xen just fine. [the SuSE guys don't think using negative
segment offsets gives a significant performance increase for them, so they
chose to avoid the inconvenience entirely]
On 64-bit systems, the TLS implementations used by Linux are a non-issue
anyhow.
Cheers,
Mark
--
Dave: Just a question. What use is a unicyle with no seat? And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2006-02-22 14:09 UTC | newest]
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2006-02-21 15:42 A question about TLS libraries in case of Xen integration in Linux Philippe Berthault
2006-02-21 16:59 ` Rik van Riel
2006-02-22 14:09 ` Mark Williamson
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