From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Evans Subject: Re: profiling active RHEL 4 PV domains with xenoprof Date: Fri, 29 Jan 2010 13:11:44 -0800 Message-ID: <4B634F10.4060800@yahoo-inc.com> References: <4B623BED.6090603@yahoo-inc.com> 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: George Dunlap Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 01/29/10 04:41, George Dunlap wrote: > Re the PV kernels: are you sure that the PV kernel has support for Xen > profiling? PV xenoprofile makes hypercalls to Xen to set up the > performance event counters. But if that isn't set up properly, or for > some other reason doesn't work right, the guest oprofile may default > back to using only timers, for which it doesn't need Xen's help (but > which are less accurate especially in a virtual environment). > I'm pretty sure RHEL 4's 2.6.9 kernel doesn't have the xenoprof patches, but I haven't looked yet. I'm going to try the 2.6.18 xenU kernel I built from the xen-unstable tree and see how that goes. thanks, -Andrew