* [Qemu-devel] kqemu vs Standard
@ 2005-02-15 17:55 Jason Brittain
2005-02-15 18:28 ` Karel Gardas
2005-02-15 19:43 ` James Mastros
0 siblings, 2 replies; 8+ messages in thread
From: Jason Brittain @ 2005-02-15 17:55 UTC (permalink / raw)
To: qemu-devel
Hi Qemu developers & users!
I'm reporting in to say that I've lightly tested Qemu/kqemu, and found it
to be significantly faster with both XP and Linux guest OSs.
I tested with the following setup:
Real Hardware: IBM Thinkpad T42p, pentium M 1.80GHz, 1GB RAM, 60G IDE HD
Host OS: Fedora Core 3 "everything" installation, very slight kernel
reconfig changes.
Guest OS: XP Corp. SP1
----------------------
This feels noticeably faster. Double clicking on icons works a bit better,
although it doesn't work all that well still. Instead, I right click on
icons and select "Open". :) The programs run faster as well, but I'm not
sure yet how I could test how much faster. Plus, I'm happy with it, so I
may not spend much time figuring that out.
XP boot, all the way to the desktop:
65 seconds regular
45 seconds kqemu
Also, due to other changes that were checked in either at the same time as
kqemu, or just before, I believe some bugs were fixed because some errors
I used to get running some of the software I run are now gone.
Guest OS: RedHat Linux 9, modified to run a 2.6 kernel
------------------------------------------------
This boots much faster now, as the numbers below show.
Linux boot, all the way to the text (non-graphical) login prompt:
86 seconds regular
36 seconds kqemu
Probably also due to numberous bug fixes checked in recently, my Java VM/Tomcat
installation now runs inside qemu without crashing with a HotSpot VM error.
It used to run for a bit, then crash, and there wasn't anything I could do
about it other than run a newer version of Sun's JVM. Now, it just works. :)
I'm not yet sure if it works in the unaccelerated mode. I'm about to test that.
Also, in unaccelerated mode, the Java VM runs very slow versus natively. But,
using kqemu, it's decently fast. Fast enough to develop with it running inside
qemu. Excellent!
A Little More About How I Tested
--------------------------------
This was all done with qemu source from CVS as of the day Fabrice
checked in kqemu. I compiled it on FC3 like:
# ./configure
# make
# make install
So, nothing fancy there.
To switch between kqemu-accelerated, and standard (unaccelerated), all
I did was load or unload the kqemu module. Yes, when I ran qemu with
it unloaded I did get the output warning saying the acceleration was
disabled.
Here's my real (laptop) hardware's CPU info:
# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 13
model name : Intel(R) Pentium(R) M processor 1.80GHz
stepping : 6
cpu MHz : 599.679
cache size : 2048 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr mce cx8 mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe est tm2
bogomips : 1187.84
--
Jason Brittain
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] kqemu vs Standard
2005-02-15 17:55 [Qemu-devel] kqemu vs Standard Jason Brittain
@ 2005-02-15 18:28 ` Karel Gardas
2005-02-15 18:55 ` Jason Brittain
2005-02-15 19:43 ` James Mastros
1 sibling, 1 reply; 8+ messages in thread
From: Karel Gardas @ 2005-02-15 18:28 UTC (permalink / raw)
To: qemu-devel
On Tue, 15 Feb 2005, Jason Brittain wrote:
> Here's my real (laptop) hardware's CPU info:
> # cat /proc/cpuinfo
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 6
> model : 13
> model name : Intel(R) Pentium(R) M processor 1.80GHz
> stepping : 6
> cpu MHz : 599.679
I just wonder, but do you usually work with CPU clocked-down? Or have you
tested running on battery?
Cheers,
Karel
--
Karel Gardas kgardas@objectsecurity.com
ObjectSecurity Ltd. http://www.objectsecurity.com
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] kqemu vs Standard
2005-02-15 18:28 ` Karel Gardas
@ 2005-02-15 18:55 ` Jason Brittain
2005-02-15 19:43 ` Thomas Petazzoni
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Jason Brittain @ 2005-02-15 18:55 UTC (permalink / raw)
To: qemu-devel
Karel Gardas wrote:
> On Tue, 15 Feb 2005, Jason Brittain wrote:
>
>>Here's my real (laptop) hardware's CPU info:
>># cat /proc/cpuinfo
>>processor : 0
>>vendor_id : GenuineIntel
>>cpu family : 6
>>model : 13
>>model name : Intel(R) Pentium(R) M processor 1.80GHz
>>stepping : 6
>>cpu MHz : 599.679
>
> I just wonder, but do you usually work with CPU clocked-down? Or have you
> tested running on battery?
Interesting! I wrote the email about all this while riding to work on
the subway. So, when I did the "cat /proc/cpuinfo", I was indeed running
on battery power. But, currently, I'm not, and still says the same thing.
Anyone know what the deal is with that? Is that an accurate number
saying that my cpu is throttled down? Could I make it run faster then?
Hmmmm..
--
Jason Brittain
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] kqemu vs Standard
2005-02-15 17:55 [Qemu-devel] kqemu vs Standard Jason Brittain
2005-02-15 18:28 ` Karel Gardas
@ 2005-02-15 19:43 ` James Mastros
1 sibling, 0 replies; 8+ messages in thread
From: James Mastros @ 2005-02-15 19:43 UTC (permalink / raw)
To: qemu-devel
Jason Brittain wrote:
> Real Hardware: IBM Thinkpad T42p, pentium M 1.80GHz, 1GB RAM, 60G IDE HD
> Host OS: Fedora Core 3 "everything" installation, very slight kernel
> reconfig changes.
> Here's my real (laptop) hardware's CPU info:
> # cat /proc/cpuinfo
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 6
> model : 13
> model name : Intel(R) Pentium(R) M processor 1.80GHz
> stepping : 6
> cpu MHz : 599.679
Make sure "machine check exception" and "check for P4 thermal throttling
interrupt" are both on in your kernel config, under "Processor type and
features". Then check your dmesg for warnings about overheating.
Under the next menu, if you're using ACPI, then make sure to turn on IBM
laptop extras. Under CPU Frequency scaling, do what seems right for
your hw.
Of course, none of this actually has anything to do with qemu.
-=- James Mastros
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] kqemu vs Standard
2005-02-15 18:55 ` Jason Brittain
@ 2005-02-15 19:43 ` Thomas Petazzoni
2005-02-15 20:05 ` Magnus Damm
2005-02-15 20:18 ` Darryl Dixon
2 siblings, 0 replies; 8+ messages in thread
From: Thomas Petazzoni @ 2005-02-15 19:43 UTC (permalink / raw)
To: qemu-devel
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Hello,
Jason Brittain a écrit :
> Anyone know what the deal is with that? Is that an accurate number
> saying that my cpu is throttled down? Could I make it run faster then?
Do something like : "watch -n 1 "cat /proc/cpuinfo | grep Mhz" and then
do something that needs CPU power on your laptop. Normally, you should
see an increase of the frequency.
If not, it's because your laptop is not properly configured I think. You
should have a look at powernowd and other frequency scaling stuff.
Thomas
--
PETAZZONI Thomas - thomas.petazzoni@enix.org
http://thomas.enix.org - Jabber: thomas.petazzoni@jabber.dk
KOS: http://kos.enix.org/ - SOS: http://sos.enix.org
Fingerprint : 0BE1 4CF3 CEA4 AC9D CC6E 1624 F653 CB30 98D3 F7A7
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 256 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] kqemu vs Standard
2005-02-15 18:55 ` Jason Brittain
2005-02-15 19:43 ` Thomas Petazzoni
@ 2005-02-15 20:05 ` Magnus Damm
2005-02-15 20:59 ` Jason Brittain
2005-02-15 20:18 ` Darryl Dixon
2 siblings, 1 reply; 8+ messages in thread
From: Magnus Damm @ 2005-02-15 20:05 UTC (permalink / raw)
To: qemu-devel
On Tue, 15 Feb 2005 10:55:28 -0800, Jason Brittain
<jason@brittainweb.org> wrote:
> Karel Gardas wrote:
> > On Tue, 15 Feb 2005, Jason Brittain wrote:
> >
> >>Here's my real (laptop) hardware's CPU info:
> >># cat /proc/cpuinfo
> >>processor : 0
> >>vendor_id : GenuineIntel
> >>cpu family : 6
> >>model : 13
> >>model name : Intel(R) Pentium(R) M processor 1.80GHz
> >>stepping : 6
> >>cpu MHz : 599.679
> >
> > I just wonder, but do you usually work with CPU clocked-down? Or have you
> > tested running on battery?
>
> Interesting! I wrote the email about all this while riding to work on
> the subway. So, when I did the "cat /proc/cpuinfo", I was indeed running
> on battery power. But, currently, I'm not, and still says the same thing.
>
> Anyone know what the deal is with that? Is that an accurate number
> saying that my cpu is throttled down? Could I make it run faster then?
> Hmmmm..
On a 2.6-kernel with cpufreq enabled, have a look at the files in
"/sys/devices/system/cpu/cpu0/cpufreq/". Try to echo "powersave" or
"performance" to scaling_governor. Then look at "/proc/cpuinfo" to see
the actual MHz.
You can also play around with acpi throttling in
"/proc/acpi/processor/*/throttling". I guess * should be replaced with
CPU0, but on my crappy laptop with wierd acpi info CPU1 must be used
instead of CPU0.
Also, try cpufreqd or cpudyn to adjust the cpu frequency on the fly.
/ magnus
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] kqemu vs Standard
2005-02-15 18:55 ` Jason Brittain
2005-02-15 19:43 ` Thomas Petazzoni
2005-02-15 20:05 ` Magnus Damm
@ 2005-02-15 20:18 ` Darryl Dixon
2 siblings, 0 replies; 8+ messages in thread
From: Darryl Dixon @ 2005-02-15 20:18 UTC (permalink / raw)
To: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 1349 bytes --]
That's just the natural effect of the Speedstep technology throttling
back the cpu to lower heat because you aren't using many cpu cycles at
the moment (you aren't pushing your laptop very hard :). If you were to
do something like, say, compile Wine, and while it is compiling
cat /proc/cpuinfo, you would see that the speed is up at 1800MHz.
Cheers,
D
On Tue, 2005-02-15 at 10:55 -0800, Jason Brittain wrote:
> Karel Gardas wrote:
> > On Tue, 15 Feb 2005, Jason Brittain wrote:
> >
> >>Here's my real (laptop) hardware's CPU info:
> >># cat /proc/cpuinfo
> >>processor : 0
> >>vendor_id : GenuineIntel
> >>cpu family : 6
> >>model : 13
> >>model name : Intel(R) Pentium(R) M processor 1.80GHz
> >>stepping : 6
> >>cpu MHz : 599.679
> >
> > I just wonder, but do you usually work with CPU clocked-down? Or have you
> > tested running on battery?
>
> Interesting! I wrote the email about all this while riding to work on
> the subway. So, when I did the "cat /proc/cpuinfo", I was indeed running
> on battery power. But, currently, I'm not, and still says the same thing.
>
> Anyone know what the deal is with that? Is that an accurate number
> saying that my cpu is throttled down? Could I make it run faster then?
> Hmmmm..
>
--
Darryl Dixon <esrever_otua@pythonhacker.is-a-geek.net>
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] kqemu vs Standard
2005-02-15 20:05 ` Magnus Damm
@ 2005-02-15 20:59 ` Jason Brittain
0 siblings, 0 replies; 8+ messages in thread
From: Jason Brittain @ 2005-02-15 20:59 UTC (permalink / raw)
To: qemu-devel
Magnus Damm wrote:
>>
>>Interesting! I wrote the email about all this while riding to work on
>>the subway. So, when I did the "cat /proc/cpuinfo", I was indeed running
>>on battery power. But, currently, I'm not, and still says the same thing.
>>
>>Anyone know what the deal is with that? Is that an accurate number
>>saying that my cpu is throttled down? Could I make it run faster then?
>>Hmmmm..
>
> On a 2.6-kernel with cpufreq enabled, have a look at the files in
> "/sys/devices/system/cpu/cpu0/cpufreq/". Try to echo "powersave" or
> "performance" to scaling_governor. Then look at "/proc/cpuinfo" to see
> the actual MHz.
Ahh, yeah. I did:
# echo "performance" >> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
And now my /proc/cpuinfo looks like:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 13
model name : Intel(R) Pentium(R) M processor 1.80GHz
stepping : 6
cpu MHz : 1799.038
cache size : 2048 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr mce cx8 mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe est tm2
bogomips : 3563.52
BUT, I retried my tests and the performance numbers/timings came out the same.
> You can also play around with acpi throttling in
> "/proc/acpi/processor/*/throttling". I guess * should be replaced with
> CPU0, but on my crappy laptop with wierd acpi info CPU1 must be used
> instead of CPU0.
>
> Also, try cpufreqd or cpudyn to adjust the cpu frequency on the fly.
Thanks for the tips on those. I'll look into them.
Darryl Dixon wrote:
> That's just the natural effect of the Speedstep technology throttling
> back the cpu to lower heat because you aren't using many cpu cycles at
> the moment (you aren't pushing your laptop very hard :). If you were to
> do something like, say, compile Wine, and while it is compiling cat
> /proc/cpuinfo, you would see that the speed is up at 1800MHz.
I believe this, since the CPU performance turned out the same either way.
More good info.. thanks!
--
Jason Brittain
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2005-02-15 21:23 UTC | newest]
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2005-02-15 17:55 [Qemu-devel] kqemu vs Standard Jason Brittain
2005-02-15 18:28 ` Karel Gardas
2005-02-15 18:55 ` Jason Brittain
2005-02-15 19:43 ` Thomas Petazzoni
2005-02-15 20:05 ` Magnus Damm
2005-02-15 20:59 ` Jason Brittain
2005-02-15 20:18 ` Darryl Dixon
2005-02-15 19:43 ` James Mastros
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