From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Ehrhardt Subject: Re: Performance Counter Virtualization in Xen Date: Mon, 21 May 2007 08:36:32 +0200 Message-ID: <46513DF0.3000105@linux.vnet.ibm.com> References: <537C6C0940C6C143AA46A88946B8541708160B01@ORNLEXCHANGE.ornl.gov> <08CA2245AFCF444DB3AC415E47CC40AFB5264C@G3W0072.americas.hpqcorp.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <08CA2245AFCF444DB3AC415E47CC40AFB5264C@G3W0072.americas.hpqcorp.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Santos, Jose Renato G" Cc: "Bhatia, Nikhil" , xen-devel@lists.xensource.com, xen-users@lists.xensource.com, xen-ppc-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Well it's not "x86 architectures", but the current profiling support in=20 xen on powerpc allows the use of performance counters from the domains=20 as used from non-virtualized environments. It is currently only tested with oprofile and has to be considered=20 experimental because there are some known issues, but depending on your=20 needs this might work for you. As far as I read on=20 http://icl.cs.utk.edu/papi/custom/index.html?lid=3D62&slid=3D96 PAPI has=20 PPC970 support. I do not know PAPI in detail, but it is possible that you can run it=20 with less/no patching xen/linux on the current xenppc head. Santos, Jose Renato G wrote: > You are right, currently the only available tool for using hardware=20 > performance counters in Xen is XenOprofile. To expose a more generic=20 > API to guests such as Perfmon, we would need to virtualize performance=20 > counters. One of the challenges of virtualizing performance counters=20 > is the high cost of saving and restoring perf. counters on domain=20 > context switches. It may be possible to do some optimizations such as=20 > lazy save/restore that could help. Also it is expected that the cost=20 > for accessing performance counters is going to be better in new=20 > processors that are coming out from Intel and AMD. afaik, no one is=20 > actively working on virtualizing HW performance counters in Xen. > =20 > For other software metrics such as number of I/O operations you can=20 > try Xenmon which report values of Xen performance counters (i.e SW=20 > counters). > Regards > =20 > Renato > > -------------------------------------------------------------------= ----- > *From:* xen-devel-bounces@lists.xensource.com > [mailto:xen-devel-bounces@lists.xensource.com] *On Behalf Of > *Bhatia, Nikhil > *Sent:* Friday, May 18, 2007 12:15 PM > *To:* xen-users@lists.xensource.com > *Cc:* xen-devel@lists.xensource.com > *Subject:* [Xen-devel] Performance Counter Virtualization in Xen > > Hello Xenthusiasts, > > =20 > > I have a few questions regarding the performance monitoring of > applications and domains running on the latest version of Xen VMM > via the performance monitoring counters available in x86 > architectures. > > =20 > > - I have used Xenoprof by patching Xen-3.0.2 Xenolinux > and the Oprofile layer which enabled me to collect performance > counter values per domain (for a passive domain) and per > application (for an active domain). I was able to perform the > profiling via command line interface using Opcontrol and then > reporting the counters using Opreport. However, I was unable to > find a way to profile an application (using an API like PAPI) > because the perfctr port was not available for Xen. Is there a way > through which applications can be monitored using performance > counters? > > =20 > > - Is there a Xen tool/utility which provides meaningful > information about per-domain metrics for dynamic memory usage > (e.g. reserved memory by Xen, total heap size in use, swap space > reserved per domain etc.), I/O done to/from the disc and the bytes > sent/received from the network over fixed intervals of time? > > =20 > > =20 > > Thanks, > > Best Regards, > > Nikhil > > -----------------------------------------------------------------------= - > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel > =20 --=20 Gr=FCsse / regards,=20 Christian Ehrhardt IBM Linux Technology Center, Open Virtualization +49 7031/16-3385 Ehrhardt@linux.vmnet.ibm.com Ehrhardt@de.ibm.com IBM Deutschland Entwicklung GmbH Vorsitzender des Aufsichtsrats: Johann Weihen=20 Gesch=E4ftsf=FChrung: Herbert Kircher=20 Sitz der Gesellschaft: B=F6blingen Registergericht: Amtsgericht Stuttgart, HRB 243294