Unix Technical Forum

cpu throttling and frequency check

This is a discussion on cpu throttling and frequency check within the Slackware Linux Support forums, part of the Unix Operating Systems category; --> Hello, I do "echo -n 1 > throttling" in /proc/acpi/processor/CPU1 and CPU2 and then check /proc/acpi/processor/CPU0/throttling. It looks like ...


Go Back   Unix Technical Forum > Unix Operating Systems > Slackware Linux Support

FAQ Members List Calendar Search Today's Posts Mark Forums Read
  #1 (permalink)  
Old 07-04-2008, 03:38 PM
pkajak
 
Posts: n/a
Default cpu throttling and frequency check

Hello,

I do "echo -n 1 > throttling" in /proc/acpi/processor/CPU1 and CPU2 and
then check /proc/acpi/processor/CPU0/throttling. It looks like this:

state count: 8
active state: T1
states:
T0: 00%
*T1: 12%
T2: 25%
T3: 37%
T4: 50%
T5: 62%
T6: 75%
T7: 87%

So I presume that current CPU frequency should be 12% of 2.4GHz but in
/proc/cpuinfo I see:

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz
stepping : 6
cpu MHz : 2400.239
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes

Do you have any suggestions how to make it work properly?

Regards PKajak
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #2 (permalink)  
Old 07-04-2008, 03:38 PM
Grant
 
Posts: n/a
Default Re: cpu throttling and frequency check

On Fri, 04 Jul 2008 09:54:42 +0200, pkajak <pkajak@slcj.uw.edu.pl> wrote:

>Hello,
>
> I do "echo -n 1 > throttling" in /proc/acpi/processor/CPU1 and CPU2 and
>then check /proc/acpi/processor/CPU0/throttling. It looks like this:
>
>state count: 8
>active state: T1
>states:
> T0: 00%
> *T1: 12%
> T2: 25%
> T3: 37%
> T4: 50%
> T5: 62%
> T6: 75%
> T7: 87%
>
>So I presume that current CPU frequency should be 12% of 2.4GHz but in
>/proc/cpuinfo I see:
>
>processor : 0
>vendor_id : GenuineIntel
>cpu family : 6
>model : 15
>model name : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz
>stepping : 6
>cpu MHz : 2400.239
>cache size : 4096 KB
>physical id : 0
>siblings : 2
>core id : 0
>cpu cores : 2
>fdiv_bug : no
>hlt_bug : no
>f00f_bug : no
>coma_bug : no
>fpu : yes
>fpu_exception : yes
>cpuid level : 10
>wp : yes
>
>Do you have any suggestions how to make it work properly?


I think you'll find that throttling is a percentage on/off state setting,
not percent of speed setting. Thus the speed setting is correctly shown
at the full rate. IOW the CPU goes full speed at the throttled rate in
time --> 12.5 percent being 1/8 go and 7/8 stop.

Grant.
--
http://bugsplatter.mine.nu/
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #3 (permalink)  
Old 07-04-2008, 03:38 PM
Sylvain Robitaille
 
Posts: n/a
Default Re: cpu throttling and frequency check

Grant wrote:

>>states:
>> T0: 00%
>> *T1: 12%
>> T2: 25%
>> T3: 37%
>> T4: 50%
>> T5: 62%
>> T6: 75%
>> T7: 87%

>
> ... the CPU goes full speed at the throttled rate in
> time --> 12.5 percent being 1/8 go and 7/8 stop.


I'm pretty sure it's the other way around, though: "throttled 12% of the
time". Else "T0" (which appears to be the default on several systems
I've checked) would amount to "the CPU is running 0% of the time". I'm
pretty sure that isn't the case on my systems. ;-)

--
----------------------------------------------------------------------
Sylvain Robitaille syl@alcor.concordia.ca

Systems and Network analyst Concordia University
Instructional & Information Technology Montreal, Quebec, Canada
----------------------------------------------------------------------
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #4 (permalink)  
Old 07-05-2008, 01:16 AM
Grant
 
Posts: n/a
Default Re: cpu throttling and frequency check

On Fri, 4 Jul 2008 15:02:53 +0000 (UTC), Sylvain Robitaille <syl@alcor.concordia.ca> wrote:

>Grant wrote:
>
>>>states:
>>> T0: 00%
>>> *T1: 12%
>>> T2: 25%
>>> T3: 37%
>>> T4: 50%
>>> T5: 62%
>>> T6: 75%
>>> T7: 87%

>>
>> ... the CPU goes full speed at the throttled rate in
>> time --> 12.5 percent being 1/8 go and 7/8 stop.

>
>I'm pretty sure it's the other way around, though: "throttled 12% of the
>time". Else "T0" (which appears to be the default on several systems
>I've checked) would amount to "the CPU is running 0% of the time". I'm
>pretty sure that isn't the case on my systems. ;-)


Yeah, I'm easily confused ) Of course T0 is throttled 0% of the time...

Grant.
--
http://bugsplatter.mine.nu/
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On
Forum Jump


All times are GMT. The time now is 02:18 AM.


Powered by vBulletin® Version 3.6.5
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.2.0
www.UnixAdminTalk.com