Arch Linux

1311219

Member

From: Sweden

Registered: 2007-01-09

Posts: 121

timeout activated cpu frequency manipulation.

Phew, that subject got a bit weird...:P

I'm not sure I posted tis in the right forum section. I have played around with cpufrequtils and cpufreqd, and tried to make the cpu frequency drop to the lowest possible when not needed, and go as high as possible whenever theres some extra work for the cpu.

I have tried the "ondemand" policy, it work great except that it doesn't react enough (the frequency (almost) only rises when I compile something, like the kernel). And I have tried setting up a custom setup with cpufreqd (when the workload is more than 10% the frequency goes to 2.8GHz, when it's 0%-4%, it goes down to ~350Khz, and between (when it's a bit unclear if the highest frequency is needed), it goes to 1.4GHz, it has worked great. But the time it takes for cpufreqd to notice if I, for example, continue use firefox after leaving it for a while, is around an (annoying:/) half second (before the frequency rises).

I have no real reason to let the frequency drop directly when not needed, so I started to think about the dpms system for X11, which turns of the screen after a specified time of inactivity.

My question is as following: Would it bee possible to change the cpufreqd policy to ondemand when dpms starts?

                      / [dpms activated] \
                     /                    \
                  true?                false?
                   /                         \
         [cpu_interval=0-10]      [policy=performance]
           /
[policy=ondemand]

thanks for any help!:)

(update: changed "powersave" to "ondemand")

Last edited by 1311219 (2007-06-06 19:38:28)

Ramses de Norre

Member

From: Leuven - Belgium

Registered: 2007-03-27

Posts: 1,289

Re: timeout activated cpu frequency manipulation.

It would be nice for sure, but have you thought about people who use cpufreqd without X?
I don't know the in and outs of cpufreqd (I just installed powernowd and put it in my daemons list...) but I think that's a point you need to consider.
Anyway I'd use your governor if it came available

1311219

Member

From: Sweden

Registered: 2007-01-09

Posts: 121

Re: timeout activated cpu frequency manipulation.

Made some small changes (why didn't I think of "ondemand" before (the only time the cpu is really needed when I'm not using the computer would be when compiling, and that will surely be detected by "ondemand")?:lol:)

Off course, I will share my configuration if I find any solution.;)

tom5760

Member

From: Philadelphia, PA, USA

Registered: 2006-02-05

Posts: 283

Website

Re: timeout activated cpu frequency manipulation.

This is a complete guess, but is an acpi event sent out when your monitor turns off?  You can check with the 'acpi_listen' command.  If it does, you could add a line to the switch statement in /etc/acpi/handler.sh that runs 'cpufreq-set -g powersave' or something.

1311219

Member

From: Sweden

Registered: 2007-01-09

Posts: 121

Re: timeout activated cpu frequency manipulation.

It might be because I'm using a custom kernel, but I'm not sure I have acpi activated(!) (or do I need to install another setup of tool to get acpi_listen, and those /etc/ dirs ?)

I'm going to try booting to the stock kernel (and also search through the pacman database and wiki), and see if I can get your idea to work, tomorrow.:)

btw: the way you describe would set the governor to ondemand, I guess theres some way to switch back to performance, by another ("screen on") interrupt?

Last edited by 1311219 (2007-06-06 20:20:34)

tom5760

Member

From: Philadelphia, PA, USA

Registered: 2006-02-05

Posts: 283

Website

Re: timeout activated cpu frequency manipulation.

You should install acpid

pacman -Sy acpid

And yeah, if the monitor switching does actually send events (I have no idea), then you could set a handler for that too.

1311219

Member

From: Sweden

Registered: 2007-01-09

Posts: 121

Re: timeout activated cpu frequency manipulation.

Sorry for the delay.

I have read the xset manpage, the q option seems to be all thats needed!:D

So what would you guys say, would a simple backgrounded (daemon) script sleeping for ~10 seconds and then query xset for the status be an acceptable solution?