From mboxrd@z Thu Jan 1 00:00:00 1970 From: david ahern Subject: performance question Date: Thu, 20 Mar 2008 12:01:26 -0600 Message-ID: <47E2A676.4020300@cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kvm-devel Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org I am trying to understand spikes in system time that I am seeing in a VM. The guest OS is RHEL4, with 2 vpcus, and 2.5Gb RAM; host is running 2.6.24.2 kernel. kvm version is kvm-63. Using the stat scripts Christian Ehrhardt posted a few days ago (thanks, Christian, very handy tool) I collected kvm_stat data as a function of time (I added time to the output). Comparing plots of guest system time to plots of kvm_stat the spikes in system time most correlate to the following kvm_stat variables: mmu_cache_miss mmu_flooded mmu_pte_updated mmu_pte_write mmu_shadow_zapped pf_fixed pf_guest remote_tlb_flush tlb_flush Can someone provide some guidance/hints on what would cause spikes in the above and if there is anything I can do to improve it? The load on the VM is fairly constant (network traffic of ~48kB/sec received and ~189kB/sec transmit) with some moderate disk IO as well. thanks, david ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/