From mboxrd@z Thu Jan 1 00:00:00 1970 From: Erik Jacobson Subject: Re: slow guest performance with build load, looking for ideas Date: Mon, 15 Jun 2009 09:15:42 -0500 Message-ID: <20090615141542.GA17448@sgi.com> References: <20090612210443.GA21840@sgi.com> <4A34C3D2.9020009@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Erik Jacobson , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from relay2.sgi.com ([192.48.179.30]:36064 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751689AbZFOOPm (ORCPT ); Mon, 15 Jun 2009 10:15:42 -0400 Content-Disposition: inline In-Reply-To: <4A34C3D2.9020009@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: > What is the host cpu type? On pre-Nehalem/Barcelona processors kvm has > poor scalability in mmu intensive workloads like kernel builds. Thanks for getting back to me. Today is pretty booked but I'm going to go find a Nehalem system and try to run similar tests to compare. I'll post my results to this thread. So if I understand what you're saying: best not to use kvm guests for build servers with pre-Nehalem processors. Both systems I used were pre-Nehalem. Here is a cpuinfo snip from both systems I tested on: processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU E5345 @ 2.33GHz stepping : 7 cpu MHz : 2327.500 cache size : 4096 KB physical id : 1 siblings : 4 core id : 3 cpu cores : 4 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr dca lahf_lm bogomips : 4655.14 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: and processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Xeon(R) CPU X5460 @ 3.16GHz stepping : 6 cpu MHz : 3158.307 cache size : 6144 KB physical id : 1 siblings : 4 core id : 3 cpu cores : 4 apicid : 7 initial apicid : 7 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 lahf_lm tpr_shadow vnmi flexpriority bogomips : 6317.51 clflush size : 64 cache_alignment : 64 address sizes : 38 bits physical, 48 bits virtual power management: