From: Avi Kivity <avi@redhat.com>
To: Erik Jacobson <erikj@sgi.com>
Cc: Mark McLoughlin <markmc@redhat.com>,
kvm@vger.kernel.org, Jes Sorensen <jes@sgi.com>
Subject: Re: slow guest performance with build load, looking for ideas
Date: Sun, 12 Jul 2009 11:38:18 +0300 [thread overview]
Message-ID: <4A59A0FA.4010408@redhat.com> (raw)
In-Reply-To: <20090709180110.GB14935@sgi.com>
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
next prev parent reply other threads:[~2009-07-12 8:35 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-12 21:04 slow guest performance with build load, looking for ideas Erik Jacobson
2009-06-14 9:33 ` Avi Kivity
2009-06-15 14:15 ` Erik Jacobson
2009-06-15 14:24 ` Avi Kivity
2009-06-15 15:25 ` Michael Tokarev
2009-06-15 15:27 ` Avi Kivity
2009-06-16 7:03 ` Michael Tokarev
2009-06-16 8:07 ` Avi Kivity
2009-06-18 23:07 ` Erik Jacobson
2009-06-28 14:17 ` Avi Kivity
2009-06-28 19:05 ` Erik Jacobson
2009-06-28 21:28 ` Avi Kivity
2009-07-01 21:41 ` Erik Jacobson
2009-07-02 5:48 ` Avi Kivity
2009-07-02 9:41 ` Avi Kivity
2009-07-03 15:43 ` Mark McLoughlin
2009-07-03 16:28 ` Erik Jacobson
2009-07-09 2:36 ` Erik Jacobson
2009-07-09 7:48 ` Avi Kivity
2009-07-09 18:01 ` Erik Jacobson
2009-07-12 8:38 ` Avi Kivity [this message]
2009-07-16 12:20 ` Jes Sorensen
2009-07-25 14:33 ` Avi Kivity
2009-07-03 10:41 ` Matty
2009-07-05 8:07 ` Avi Kivity
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