From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: slow guest performance with build load, looking for ideas Date: Sun, 12 Jul 2009 11:38:18 +0300 Message-ID: <4A59A0FA.4010408@redhat.com> References: <20090618230744.GA19307@sgi.com> <4A477B8C.2010502@redhat.com> <20090628190500.GA7347@sgi.com> <4A47E06A.7040700@redhat.com> <20090701214128.GA1380@sgi.com> <4A4C4A28.1060105@redhat.com> <4A4C80AD.7010204@redhat.com> <1246635797.13604.7.camel@blaa> <20090709023633.GB29409@sgi.com> <4A55A0E1.1060501@redhat.com> <20090709180110.GB14935@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Mark McLoughlin , kvm@vger.kernel.org, Jes Sorensen To: Erik Jacobson Return-path: Received: from mx2.redhat.com ([66.187.237.31]:54196 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753844AbZGLIf1 (ORCPT ); Sun, 12 Jul 2009 04:35:27 -0400 In-Reply-To: <20090709180110.GB14935@sgi.com> Sender: kvm-owner@vger.kernel.org List-ID: On 07/09/2009 09:01 PM, Erik Jacobson wrote: > >> Please drop -usbdevice tablet and set the host I/O scheduler to >> deadline. Add cache=none to the -drive options. >> > > yes, these changes make a difference. > > > Before starting qemu-kvm, I did this to change the IO scheduler: > BEFORE: > # for f in /sys/block/sd*/queue/scheduler; do cat $f; done > noop anticipatory deadline [cfq] > noop anticipatory deadline [cfq] > > SET: > # for f in /sys/block/sd*/queue/scheduler; do echo "deadline"> $f; done > > CONFIRM: > # for f in /sys/block/sd*/queue/scheduler; do cat $f; done > noop anticipatory [deadline] cfq > noop anticipatory [deadline] cfq > > > qemu command line. Note that usbtablet is off and cache=none is used in > drive options: > > /usr/bin/qemu-kvm -M pc -m 4096 -smp 8 -name f11-test -uuid b7b4b7e4-9c07-22aa-0c95-d5c8a24176c5 -monitor pty -pidfile /var/run/libvirt/qemu//f11-test.pid -drive file=/var/lib/libvirt/images/f11-test.img,if=virtio,index=0,boot=on,cache=none -drive file=/dev/sdb,if=virtio,index=1,cache=none -drive file=/var/lib/libvirt/images/test.img,if=virtio,index=2,cache=none -net nic,macaddr=54:52:00:46:48:0e,model=virtio -net user -serial pty -parallel none -usb -vnc cct201:1 -soundhw es1370 -redir tcp:5555::22 > > > # rotation enabled this way in the guest, once the guest was started: > for f in /sys/block/vd*/queue/rotational; do echo 1> $f; done > > Test runs after make clean... > time (make -j12&& make -j12 modules) > > real 10m25.585s > user 26m36.450s > sys 8m14.776s > > 2nd trial (make clean followed by the same test again. > real 9m21.626s > user 26m42.144s > sys 8m14.532s > > That's a scaling of 3.7, still pretty far from the host and even farther than my results. Is the numa factor of this machine larger than usual? -- error compiling committee.c: too many arguments to function