Re: ondemand cpufreq ineffective in 2.6.12 ?

Eric Piel
2005-07-12T11:52:45Z

07/12/2005 01:11 PM, Ken Moffat wrote/a écrit:
> On Tue, 12 Jul 2005, Ken Moffat wrote:
>
>
>> I was going to say that niceness didn't affect what I was doing, but
>>I've just rerun it [ in 2.6.11.9 ] and I see that tar and bzip2 show up
>>with a niceness of 10. I'm starting to feel a bit out of my depth here
>
>
> OK, Con was right, and I didn't initially make the connection.
>
> In 2.6.11, untarring a .tar.bz2 causes tar and bzip2 to run with a
> niceness of 10, but everything is fine.
>
> In 2.6.12, ondemand _only_ has an effect for me in this example if I
> put on my admin hat and renice the bzip2 process (tried 0, that works) -
> renicing the tar process has no effect (obviously, that part doesn't
> push the processor).
>
> So, from a user's point of view it's broken.
Well, it's just the default settings of the kernel which has changed. If
you want the old behaviour, you can use (with your admin hat):
echo 1 > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/ignore_nice
IMHO it seems quite fair, if you have a process nice'd to 10 it probably
means you are not in a hurry.

Just by couriosity, I wonder how your processes are automatically
reniced to 10 ?

Eric