From: Aurelien Jarno <aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org>
To: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Cc: kvm-devel <kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Subject: Re: [ANNOUNCE] kvm-14 release
Date: Tue, 20 Feb 2007 23:24:20 +0100 [thread overview]
Message-ID: <45DB7514.3040409@aurel32.net> (raw)
In-Reply-To: <45DA9FFA.2020009-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Avi Kivity a écrit :
> Aurelien Jarno wrote:
>> The bad news is that kvm-14 seems to be a lot slower than kvm-12 +
>> modules from kernel 2.6.20. This is the case with a GNU/kFreeBSD guest.
>> kvm-12 was about 1.5 time faster than qemu + kqemu. kvm-20 is slower
>> than qemu without kqemu...
>>
>> Does anybody have an idea about this performance regression?
>>
>
> What is your workload? How are you measuring performance?
Sorry to answer only now, it took me some time to do some more
measurements and have some numbers. I am simply building a Debian
package (simulpic) and measuring the build time. Basically the command is:
apt-get source simulpic
cd simulpic-2005-1-28
time debuild -uc us
It surely not a performance index, but I guess it is ok to compare
performances between version. It is also quite representative of my use
of the machine.
The guest is Debian GNU/kFreeBSD amd64 (ie FreeBSD kernel + GNU libc).
It is accessed via ssh, and kvm is started with -nographic, so there is
no influence of xorg.
I am doing my tests on an Athlon X2 3800+ machine, running a 2.6.20
kernel. During all my tests, the machine is not loaded with other tasks
(except systems tasks), so qemu or kvm have a full core available. Top
shows that the core is used between 95 and 100% during the whole build
in all cases.
The tests I have made are presented below. In all cases I have verified
that the real time correspond to the time of my wall clock, it is
correct in all case given the resolution of my wall clock (1 s):
qemu
----
real 3m16.626s
user 2m22.654s
sys 0m41.738s
qemu + kqemu
------------
real 0m51.529s
user 0m11.775s
sys 0m36.215s
kvm 12 + modules from kernel 2.6.20
-----------------------------------
real 0m30.635s
user 0m16.357s
sys 0m8.511s
kvm 12
------
real 0m25.357s
user 0m16.259s
sys 0m6.496s
kvm 13
------
real 0m23.415s
user 0m15.177s
sys 0m5.811s
kvm 14
------
real 7m47.310s
user 5m17.359s
sys 2m3.184s
Using kvm 14, the system is clearly not responsive at all. You can see
that without running a benchmark.
Also running Hurd under kvm shows the same problem, though I can't make
such measurements, because it does not run under kvm < 14. Note however
that the ping time of the guest machine running Hurd during I/O
increases from a few milliseconds to a dozen of seconds.
--
.''`. Aurelien Jarno | GPG: 1024D/F1BCDB73
: :' : Debian developer | Electrical Engineer
`. `' aurel32-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org | aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org
`- people.debian.org/~aurel32 | www.aurel32.net
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next prev parent reply other threads:[~2007-02-20 22:24 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-19 11:01 [ANNOUNCE] kvm-14 release Avi Kivity
[not found] ` <45D98390.6060001-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-19 13:16 ` Daniel P. Berrange
[not found] ` <20070219131633.GF31525-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2007-02-19 13:21 ` Avi Kivity
[not found] ` <45D9A464.8040406-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-19 15:37 ` James Morris
2007-02-19 15:42 ` Avi Kivity
[not found] ` <45D9C57D.9030203-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-03-05 8:52 ` Avi Kivity
2007-02-20 1:06 ` Rusty Russell
[not found] ` <1171933567.8218.53.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2007-02-20 5:53 ` James Morris
2007-02-19 14:37 ` Andreas Hasenack
[not found] ` <200702191237.39291.ahasenack-y7mWNqJcIDpfJ/NunPodnw@public.gmane.org>
2007-02-19 14:46 ` Avi Kivity
2007-02-19 15:24 ` Omar Khan
[not found] ` <loom.20070219T161915-755-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2007-02-19 15:26 ` Avi Kivity
2007-02-19 22:34 ` Aurelien Jarno
[not found] ` <45DA25D9.1060509-rXXEIb44qovR7s880joybQ@public.gmane.org>
2007-02-20 7:15 ` Avi Kivity
[not found] ` <45DA9FFA.2020009-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-20 22:24 ` Aurelien Jarno [this message]
[not found] ` <45DB7514.3040409-rXXEIb44qovR7s880joybQ@public.gmane.org>
2007-02-21 8:06 ` Avi Kivity
[not found] ` <45DBFD6E.2060507-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-21 14:06 ` Aurelien Jarno
[not found] ` <45DC51E3.7010205-rXXEIb44qovR7s880joybQ@public.gmane.org>
2007-02-21 14:18 ` Avi Kivity
[not found] ` <45DC54B5.9080608-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-21 14:55 ` Laurent Vivier
[not found] ` <45DC5D4E.5000300-6ktuUTfB/bM@public.gmane.org>
2007-02-21 15:31 ` Anthony Liguori
[not found] ` <45DC65C9.6010104-rdkfGonbjUSkNkDKm+mE6A@public.gmane.org>
2007-02-21 16:07 ` Laurent Vivier
2007-02-22 16:35 ` Laurent Vivier
[not found] ` <45DDC641.3030001-6ktuUTfB/bM@public.gmane.org>
2007-02-22 16:38 ` Avi Kivity
[not found] ` <45DDC6F3.8080104-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-22 17:25 ` Anthony Liguori
[not found] ` <45DDD21F.4080202-rdkfGonbjUSkNkDKm+mE6A@public.gmane.org>
2007-02-22 17:29 ` Avi Kivity
[not found] ` <45DDD30D.4000809-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-22 18:12 ` Anthony Liguori
[not found] ` <45DDDD01.7030802-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2007-02-28 14:12 ` Laurent Vivier
2007-02-26 15:43 ` Aurelien Jarno
[not found] ` <45E30037.90007-rXXEIb44qovR7s880joybQ@public.gmane.org>
2007-02-26 15:57 ` Laurent Vivier
[not found] ` <45E30354.3020407-6ktuUTfB/bM@public.gmane.org>
2007-02-26 16:23 ` Avi Kivity
[not found] ` <45E3097C.7020606-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-02-26 16:46 ` Laurent Vivier
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