Arch "eats" cpu and raise temperature

MajinJoko · 2011-07-06 09:58:11

Good morning guys,

I'm on a Arch x86 with gnome.
I'm not a complete linux-noob since I've been using gentoo since 2006.

My problem is that on arch the cpu and gpu temperature are always from 5 to 10 °C higher than Gentoo.
Thanks to arch wiki, I configured cpufreq.
Trying to reproduce Gentoo settings, I installed cpufreqd (from aur, with gentoo's cpufreqd.conf) and configured the nvidia card to downclock when I log in gnome.

What looks weird to me is that if I run:
watch grep \"cpu MHz\" /proc/cpuinfo

There is ALWAYS a core at full throttle. Maybe for just 2 seconds, then it goes back to slowest speed and immediately the other one raise its speed to maximum.
I set the ondemand governor, and cpufreq-info return it set correctly.

When I'm in gnome, there is always the process "gnome-shell" that takes 2-6 % of cpu.
But when I shutdown X, and I am all alone in the shell, the top command shows no processes using too much cpu, even if the strange behaviour of cpu-speed still happens (according to watch).
In gentoo the cores stay to slowest speed for much a longer time.

My conclusion is, the temperature are so high cause the pc never really "relax" due to core strange policy with speed.

In my rc.conf, that's what about modules:
MOD_AUTOLOAD="yes"
MODULES=(fuse acpi-cpufreq cpufreq_ondemand cpufreq_performance cpufreq_powersave)
and about daemons:
DAEMONS=(@hwclock @syslog-ng @crond @dbus @gpm @net-profiles @bluetooth @cpufreq @sensors @acpid @rcpbind @nfs-common @alsa @avahi-daemon @cups @cpufreqd @gdm)

I hope somebody can help me, or maybe just show me the way to fully debug the system.

Thank you very much,
MJ

ps- I hope not to posted in the wrong forum, but the other sections seems not for this kind of problem.

stqn · 2011-07-06 14:18:13

Are you sure you should be running both cpufreq and cpufreqd daemons?
If this happens when no process is using the CPU, then I can think of two reasons: either the ondemand up_threshold is much too low, or something is switching to performance...
It's probably something else though .

MajinJoko · 2011-07-06 14:41:50

Thank you for your reply.

I don't think cpufreq and cpufreqd could be a problem, cause cpufreq is not a daemon, it just set the cpu to use the "ondemand" governor.

The ondemand up_threashold is at standard value of 95. Should I try to increase it?

I check with powertop: there are ~250 wakeup per second, while in gentoo this value is around 160. But I really don't know how much confident I can be on these values.

Thank you again.

chemicalfan · 2011-07-06 15:30:02

This doesn't help, but man you run a lot of daemons!!

Edit: Actually, isn't this obvious? Under Gentoo, you will have compiled your system for your CPU. Under Arch, the default packages will be generic i686 packages. So, more processing required to get the same result. Have you thought about recompiling gnome-shell using the ABS, as that seems to be the culprit?

Last edited by chemicalfan (2011-07-06 15:31:35)

MajinJoko · 2011-07-06 15:38:14

I really don't think the number of daemons running is so large, but I could be wrong.

No, I don't think I'm going to recompile gnome-shell, cause the same behavior happens when X is closed (and gnome-shell is not running).
The only thing I can do is try to stop one daemon at time to find out if one of them is the cause of the problem..

Durden · 2011-07-06 15:43:20

What kernel are you running? I'm sure you're aware of the current power regressions in the kernel. May or may not be related.

lukaszan · 2011-07-06 16:04:18

chemicalfan has a good point there. In gentoo everything (especially kernel) will be compiled for your pc. If you are running stock kernel and precompiled packages there will be performance decrease.

MajinJoko · 2011-07-06 16:06:57

I'm running 2.6.39-ARCH.
Ok for the power regression, but it is correct that my core 2 duo 9400 never stay at 800MHz? Is this kernel suppose to switch back to full power one core at time for just 1-2 seconds? And I am not pretty sure this could be related to high temperature ("higher temperature" is better).

I just did a deeper test: turning off one daemon at time, this strange behavior still continue to happen. Even when "rc.d list" show no active daemon. Looking to the output of "top" and "powertop" give me no info, but maybe just cause my ignorance.

For now, thanks to everyone is trying to help.
MJ

edit:
@ chemicalfan and lukaszan
I am not complaining about performance. Instead, it seems to me that this Arch is quite faster to boot and to use. I think - but I'm not very sure of it - that this fact of compiling software under Gentoo is a bit overestimated. I can agree about the possibilities of certain personalization or just the kernel lightness, but I think that if the arch kernel (or some process I am unable to identify) can't keep my proc at the lowest frequency some problem exists.

Last edited by MajinJoko (2011-07-06 16:10:46)

steve___ · 2011-07-06 16:10:24

Are you comparing the exact same version of xorg? I noticed xorg-server 1.10.2 to take up more cpu and overall it seems more sluggish relative to version 1.9.4.901

MajinJoko · 2011-07-06 16:13:51

steve___ wrote:

Are you comparing the exact same version of xorg? I noticed xorg-server 1.10.2 to take up more cpu and overall it seems more sluggish relative to version 1.9.4.901

No. In gentoo I'm running Xorg 1.9.5 while here there is version 1.10.2.
But, as I said before, I don't think is something strictly related to Xorg or gnome cause it happens even whene I'm in shell and shutdown them.

(Thank you)

Durden · 2011-07-06 16:26:39

What kernel were you using on gentoo?

MajinJoko · 2011-07-06 16:33:59

2.6.36-r5 from gentoo sources. It's a 2.6.36 with a few of gentoo patches..

Durden · 2011-07-06 17:10:49

I'm really leaning towards the power regressions in 2.6.39 to be honest with you. Using more power = more heat. 2.6.38 and 2.6.39 are both really bad in that sense. Take a look at this:
http://www.webupd8.org/2011/06/linux-ke … e-fix.html

See if that is relevant and helps at all.

MajinJoko · 2011-07-06 18:04:43

Thank you.

I read the post you link, and try to add:
pcie_aspm=force
to kernel command line.

I can see right now the frequency are still "weird", but temperature seems to be lower than before.
I need to test it, please be patient for a better answer.

What about the frequencies on your system? If you try:
watch grep \"cpu MHz\" /proc/cpuinfo
your cpu succedeed in stay quiet or it behaves like mine?

I will post my conclusions as soon as possible.

Once again, thank you very much.

stqn · 2011-07-06 22:09:35

MajinJoko wrote:

The ondemand up_threashold is at standard value of 95. Should I try to increase it?

No, I don't think so. I've set it to 50...

I check with powertop: there are ~250 wakeup per second, while in gentoo this value is around 160.

About 600 here, but I have some peer to peer software running. Powertop tells me my CPU spends 80-90% of the time at its lowest frequency, which seems ok.

MajinJoko · 2011-08-02 16:50:17

After a month of testing, I'm pretty satisfied of the actual situation.
I still see cpu-freq raising repetitively, but temperature are very good, just 1-2 °C more then Gentoo.

Thank you again!

pedromj · 2011-11-28 19:00:08

Around a month ago I moved from Debian Sid to ArchLinux and I noticed about 4°C more of system temperature. The only three big differences are:

In Arch I use GNOME 3.2 while in Debian I was using GNOME 3.0;
Arch kernel has a higher value for HZ (HZ = 300 in Arch, HZ = 250 in Debian); and
I installed the x86-64 version in Arch and in Debian I was using i386 version.

By now I don't care so much because we (in Spain) are entering winter, so the higher temperature is compensated , but for the next summer, if I still see "the problem", I think I'll build the kernel with HZ = 250 to see what happens.

Arch Linux

#1 2011-07-06 09:58:11

Arch "eats" cpu and raise temperature

#2 2011-07-06 14:18:13

Re: Arch "eats" cpu and raise temperature

#3 2011-07-06 14:41:50

Re: Arch "eats" cpu and raise temperature

#4 2011-07-06 15:30:02

Re: Arch "eats" cpu and raise temperature

#5 2011-07-06 15:38:14

Re: Arch "eats" cpu and raise temperature

#6 2011-07-06 15:43:20

Re: Arch "eats" cpu and raise temperature

#7 2011-07-06 16:04:18

Re: Arch "eats" cpu and raise temperature

#8 2011-07-06 16:06:57

Re: Arch "eats" cpu and raise temperature

#9 2011-07-06 16:10:24

Re: Arch "eats" cpu and raise temperature

#10 2011-07-06 16:13:51

Re: Arch "eats" cpu and raise temperature

#11 2011-07-06 16:26:39

Re: Arch "eats" cpu and raise temperature

#12 2011-07-06 16:33:59

Re: Arch "eats" cpu and raise temperature

#13 2011-07-06 17:10:49

Re: Arch "eats" cpu and raise temperature

#14 2011-07-06 18:04:43

Re: Arch "eats" cpu and raise temperature

#15 2011-07-06 22:09:35

Re: Arch "eats" cpu and raise temperature

#16 2011-08-02 16:50:17

Re: Arch "eats" cpu and raise temperature

#17 2011-11-28 19:00:08

Re: Arch "eats" cpu and raise temperature

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