WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-ia64-devel

RE: ´ð¸´: [Xen-ia64-devel] Re: [PATCH 0/12] various fixes related the xe

To: tgingold@xxxxxxx
Subject: RE: ´ð¸´: [Xen-ia64-devel] Re: [PATCH 0/12] various fixes related the xenrelocation
From: Alex Williamson <alex.williamson@xxxxxx>
Date: Tue, 08 Jan 2008 09:01:34 -0700
Cc: "yamahata@xxxxxxxxxxxxx" <yamahata@xxxxxxxxxxxxx>, "de Dinechin, Christophe \(Integrity VM\)" <christophe.de-dinechin@xxxxxx>, "xen-ia64-devel@xxxxxxxxxxxxxxxxxxx" <xen-ia64-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Tue, 08 Jan 2008 08:02:39 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <1199803571.47838cb30c05a@xxxxxxxxxxx>
List-help: <mailto:xen-ia64-devel-request@lists.xensource.com?subject=help>
List-id: Discussion of the ia64 port of Xen <xen-ia64-devel.lists.xensource.com>
List-post: <mailto:xen-ia64-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=unsubscribe>
Organization: HP OSLO R&D
References: <E1J65lD-0007ff-IP@host-192-168-0-1-bcn-london> <1198337331.476d2d33ed418@xxxxxxxxxxx> <7575980D7C4188408E8BDB171DA164B73A8BB361C1@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> <20080108023603.GA2513@saphi> <7575980D7C4188408E8BDB171DA164B73A8BB84FE8@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> <1199787802.47834f1a4c089@xxxxxxxxxxx> <7575980D7C4188408E8BDB171DA164B73A8BB84FF1@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> <1199803571.47838cb30c05a@xxxxxxxxxxx>
Sender: xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Tue, 2008-01-08 at 15:46 +0100, tgingold@xxxxxxx wrote:
> Quoting "de Dinechin, Christophe (Integrity VM)"
> > Do you have rough performance benchmarks for Xen running a VT-i guest right
> > now? We discarded trap-and-emulate very early in the HPVM design because an
> > early experiment had shown that on Itanium, fault handling alone amounted to
> > something like 15% performance degradation. This may have changed with more
> > recent chips, but I'm curious about this.
> 
> I don't have figure but maybe some were sent in the mailing list.  For sure
> VT-i degradation is severe.  The Xen approach is para-virtualization where a
> tiny part of the OS is rewritten.  This approach is very effective but works
> only for open source OSes.

   Of course it depends on the workload.  I just ran some kernel build
tests last Friday on the latest bits and see a bit over 9% hit for a PV
Linux guest and only about 3% more for an HVM Linux guest.  That can be
reduced to about 2% over the PV case using PV-on-HVM block drivers.
These were for UP guests on a Montvale system with warm caches, so it's
mainly a memory and computation test.  YMMV with more I/O intensive
loads.  If anyone else has some performance numbers, please share.
Thanks,

        Alex
-- 
Alex Williamson                             HP Open Source & Linux Org.


_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel

<Prev in Thread] Current Thread [Next in Thread>