From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: KVM power usage - high wakeup rates Date: Thu, 19 Jun 2008 15:17:13 -0500 Message-ID: <485ABEC9.3020800@codemonkey.ws> References: <485AA6A7.2060806@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Haydn Solomon Return-path: Received: from yx-out-2324.google.com ([74.125.44.28]:29445 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750985AbYFSURu (ORCPT ); Thu, 19 Jun 2008 16:17:50 -0400 Received: by yx-out-2324.google.com with SMTP id 31so215159yxl.1 for ; Thu, 19 Jun 2008 13:17:49 -0700 (PDT) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: Haydn Solomon wrote: > If I'm just using SDL, does usb tablet provide any benefit? > You don't have to do explicit key grab. Regards, Anthony Liguori > On Thu, Jun 19, 2008 at 2:34 PM, Anthony Liguori wrote: > >> Haydn Solomon wrote: >> >>> Hi List, >>> >>> When testing power usage of a windows xp guest using powertop utility, >>> I'm noticing high wakeup rates. The following is the output of >>> powertop for an idle windows xp guest. >>> >>> >>> ============================== >>> =========================== >>> Wakeups-from-idle per second : 2716.6 interval: 10.0s >>> no ACPI power usage estimate available >>> >>> Top causes for wakeups: >>> 52.4% (2434.4) qemu-system-x86 : sys_timer_settime (posix_timer_fn) >>> 21.5% (996.7) qemu-system-x86 : __kvm_migrate_pit_timer (pit_timer_fn) >>> 15.0% (697.4) : extra timer interrupt >>> 4.9% (227.6) : Rescheduling interrupts >>> 1.6% ( 72.9) USB device 6-2 : Optical USB Mouse (Logitech) >>> 1.3% ( 61.7) : nvidia >>> 1.3% ( 59.0) : uhci_hcd:usb4, uhci_hcd:usb6, HDA Intel >>> =================================================================== >>> >>> I'm getting similar values when running a Fedora 9 guest. >>> >>> My host is running F9. Details of my /proc/cpuinfo : >>> >>> processor : 1 >>> vendor_id : GenuineIntel >>> cpu family : 6 >>> model : 15 >>> model name : Intel(R) Core(TM)2 Duo CPU T7500 @ 2.20GHz >>> stepping : 10 >>> cpu MHz : 2201.000 >>> cache size : 4096 KB >>> physical id : 0 >>> siblings : 2 >>> core id : 1 >>> cpu cores : 2 >>> 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 pbe >>> syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor >>> ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm ida >>> bogomips : 4387.73 >>> clflush size : 64 >>> cache_alignment : 64 >>> address sizes : 36 bits physical, 48 bits virtual >>> power management: >>> >>> The linux image I'm running is Linux localhost.localdomain >>> 2.6.25.4-30.fc9.x86_64 #1 SMP Wed May 21 17:34:18 EDT 2008 x86_64 >>> x86_64 x86_64 GNU/Linux >>> >>> I'm starting my vm using the following command: >>> >>> /usr/local/kvm/bin/qemu-system-x86_64 \ >>> -hda windowsxp.img \ >>> -m 650 \ >>> -localtime \ >>> -net user \ >>> -net nic,model=e1000 \ >>> -smb /home/hsolomon \ >>> -std-vga \ >>> -soundhw all \ >>> -usb \ >>> -usbdevice tablet \ >>> -name StandardPC-NAT & >>> >>> >> USB tablet polls a lot. You'll probably see far less wake ups if you don't >> use the tablet. >> >> With the default options, my idle winxp guest causes about 550 wakeups/sec >> which is pretty close to what I'd expect. I don't think you'll get much >> better than that without using a dynticks guest. >> >> Regards, >> >> Anthony Liguori >> >> >>> Thanks >>> >>> Haydn >>> -- >>> To unsubscribe from this list: send the line "unsubscribe kvm" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> >>