[CentOS] cpuspeed problems with 5.2 and 2.6.18-92.1.18 kernelrevision

John jses27 at gmail.com
Thu Dec 18 17:24:32 UTC 2008

> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of Kai Schaetzl
> Sent: Thursday, December 18, 2008 7:18 AM
> To: centos at centos.org
> Subject: Re: [CentOS] cpuspeed problems with 5.2 and 
> 2.6.18-92.1.18 kernelrevision
> ArcosCom Linux User wrote on Thu, 18 Dec 2008 00:00:29 +0100 (CET):
> > The last try:
> >    1) Power off the laptop along 2/3 hours.
> >    2) Power on and log into gnome.
> >    3) The cpuspeed monitor shows that all is working fine.
> I don't know what this monitor is. There's a cpuspeed service 
> script. If 
> enabled it will load the necessary kernel modules and the configured 
> governor. Config is in /etc/sysconfig/cpuspeed. You can also 
> check the 
> script yourself to see what it does. It may very well be that 
> it thinks that 
> your CPU has a flaw that stops it from correctly working with 
> frequency 
> scaling. I know that the script has checks for AMD CPUs in it 
> for instance.
> If there is some cpuspeed GUI monitor, this has nothing to do 
> with the 
> cpuspeed service script. If cpuspeed is disabled the 
> performance governor 
> should be on. As I see you know where to check this. So, as I 
> said earlier, 
> shut it off (chkconfig cpuspeed off), reboot, and check the values.
> Also, if you think that this has something to do with Gnome 
> then you should 
> *not* boot in the GUI and see if you get better results.
> If that doesn't help there's more likely a problem with the 
> driver. Have you 
> checked that it is loaded?
> > # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> > 800000
> > 
> > (and I think this last value is the problem because I can't 
> change it with
> > echo "1733000" > 
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq)
> I tend to agree. That's why you want to check this value 
> without gnomem 
> without cpuspeed and also right after booting up (as you say 
> frequency 
> scales down after a few minutes, so theoretically there 
> should be a higher 
> value in the beginning and there might indeed be a problem in 
> the driver 
> that stops it from scaling up again). It's also possible that 
> the algorithm 
> for calculating the speedup is doing something wrong, so it 
> doesn't scale up 
> again, because it thinks it's not necessary. You could set 
> to something very low like 5
> >    4) Some minutes after, the speed goes down to 800 MHz 
> and no more wants
> > to grow up. I can't change to force performance or using 
> userspace and
> > select the speed.
> > 
> > Any help more about?
> > 
> > If I launch any heavy compilation (as kernel compilation), 
> the speed don't
> > want to grow up. Really is working fine under these 
> circumstances with the
> > performance governor selected?
> No, but this wasn't obvious from your earlier posting. As I 
> said: did you 
> stop cpuspeed? This is not a xen kernel, isn't it?
> About the top posting/qoting etc.: The point is to make your 
> postings as 
> readable for others as possible. If you quote what you really 
> answer to and 
> then answer that and then quote the next part you answer and 
> answer that 
> it's much easier to follow for the reader and also much 
> easier for *you* to 
> answer as you cannot easily overlook questions if you go thru 
> one by one. 
> And everything that you don't answer (including the signature 
> etc.) simply 
> doesn't belong in the quote and is omitted. You can take this 
> posting as an 
> example.
Kai is right about the cpuspeed deamon. If you stopped the service it should
and will run full speed. But there is a CATCH "dynamic cpu speed features".
This is in your BIOS Settings thay need to be disabled. Most all Mother
Boards that Supports Intel Centrino has it. Check that out.


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