From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: [Patch] support of lock profiling in Xen Date: Thu, 08 Oct 2009 10:38:46 +0200 Message-ID: <4ACDA516.6030800@ts.fujitsu.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: > On 08/10/2009 08:48, "Juergen Gross" wrote: > >> Comments welcome :-) > > There's also the question of whether this really gets you useful extra info > than can be digested from a xentrace run. I suppose at least the info is > easier to understand, and not many people know how to drive xentrace. It helped me a lot for narrowing down my performance problem with a 8 vcpu BS2000 system (this was the main reason I made the patch). Finding such a problem in xentrace is quite a bit of work. xentrace produced over 500 MB of data in 30 seconds, while reading the xenlockprof output revealed the bottleneck in seconds. And I think the lock profiling tool is much better for evaluating optimizations in Xen regarding lock conflicts, if the differences are only a few percent. Juergen -- Juergen Gross Principal Developer Operating Systems TSP ES&S SWE OS6 Telephone: +49 (0) 89 636 47950 Fujitsu Technolgy Solutions e-mail: juergen.gross@ts.fujitsu.com Otto-Hahn-Ring 6 Internet: ts.fujitsu.com D-81739 Muenchen Company details: ts.fujitsu.com/imprint.html