The tag has no usage guidance.

learn more… | top users | synonyms

16
votes
1answer
24k views

Setting CPU governor to on demand or conservative

I'm struggling with cpupower on ArchLinux. I want to set governor to ondemand or even to conservative. First if I do $ sudo cpupower frequency-info --governors, I only get performance powersave. So ...
9
votes
1answer
6k views

Can't use “userspace” cpufreq governor and set cpu frequency

I'm trying to change the cpu frequency on my laptop (running Linux), and not having any success. Here are some details: # uname -a Linux yoga 3.12.21-gentoo-r1 #4 SMP Thu Jul 10 17:32:31 HKT 2014 ...
9
votes
1answer
12k views

How to set up Linux for full AMD APU power management support: Turbo Core, Cool'n'Quiet, Dynamic Power Management?

My objective is to set up a mini server (not HTPC) with low power consumption in idle mode, yet offering nice performance when used. The focus is more on data safety than availability. In other words: ...
7
votes
3answers
6k views

Host CPU does not scale frequency when KVM guest needs it

I have asked this question on serverfault, but it could also have been posted here. I will synchronise the answers if one is found. Observation: I have an HP server with an AMD dual core CPU (Turion ...
7
votes
1answer
909 views

Can I run multiple cores at different clock speeds?

I see the cores on an Intel i5 machine I'm looking at can only be run at the same clockspeed: /sys/devices/system/cpu/cpu1/cpufreq/related_cpus lists all of the CPUs. Setting cpu1's clockspeed changes ...
6
votes
1answer
8k views

Why do cpuinfo_cur_freq and /proc/cpuinfo report different numbers?

When I do sudo watch -n1 cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq I get 1.8 - 2.7 GHz. It never goes above 2.7. And when I do watch -n1 "cat /proc/cpuinfo | grep MHz" I get ...
5
votes
1answer
1k views

How to set the CPU freq. in Linux?

I'm using this ARM9 SAM9G25 embedded system, that when switched on, is only online for a few seconds and because I want to speed up the whole process, I'd like to check the CPU frequency, and set it ...
5
votes
1answer
11k views

CentOS conservative governor, nice error

I changed my CentOS 6 CPU governor from ondemand (the default one) to conservative and got this after restarting the cpufreq service: /etc/rc5.d/S13cpuspeed: line 88: ...
5
votes
1answer
397 views

Has anyone actually tested laptop battery life under different CPU governors?

In theory, switching from the ondemand governor to conservative should save battery life on laptops. However, I don't think I've ever seen any tests done to verify this or show how significant a ...
5
votes
1answer
4k views

Setting CPU frequency guidelines

I'm changing my CPU frequency because of noisy fan. I used sudo cpufreq-selector -g powersave for this purpose, but I replaced my Linux system Xubuntu with Lubuntu because it utilizes better ...
5
votes
0answers
377 views

Loading speedstep_centrino kernel module [closed]

Because of a noisy fan in my laptop, I need to change CPU frequency and for this task I need to load the appropriate kernel module. The CPU in my laptop Acer TravelMate 4002WLMi is: $ cat ...
4
votes
1answer
869 views

Control cpu freq depending on ac/battery state

How can I make my linux system (ubuntu) automatically choose the performance governor when it works with ac and switch automatically to ondemand when it is on battery (and vice versa)? Is it also ...
3
votes
1answer
3k views

How to get ondemand governor on fedora

In Ubuntu 13.10 on my (Dual Core i5 Lenovo G570) laptop, I recently discovered the wonders of indicator-cpufreq, so I can extend my battery life dramatically by setting it to 'ondemand' or 'powersave' ...
3
votes
1answer
289 views

How to measure the clock pulse of my computer manually?

My PC has two processors, and I know that each one runs at 1.86 GHz. I have just read about clock cycles and I only have a (very) rough understanding, so I apologize beforehand if my question is so ...
3
votes
1answer
263 views

CPU Frequency changing every second

I just installed conky and recognized that my CPU-Frequency changes every second in steps of 10 to 100MHz and between 1000MHz - 2000MHz. Just wondered if this is normal behavior?
3
votes
1answer
2k views

cpufreq-set -g performance doesn't work on arch linux

acpi-cpufreq was already loaded , where the frequency was all 800MHz now , and I can't make it back to full-speed , which is 2500MHz. I tried cpufreq-set -g performance , then I check /proc/cpuinfo , ...
3
votes
1answer
661 views

Slow down CPU when it heats up

I run Gentoo Linux on my laptop. I have an issue, though, where if I'm building some very large piece of software (as I do fairly frequently, since the purpose of this laptop is development), the CPU ...
3
votes
1answer
1k views

Scaling issues of i7 3520M with intel_pstate module on Kernel 3.10.0

Few days ago I updated my openSUSE 12.3 system from Kernel 3.9.8-1.gf3348a8-desktop to 3.10.0-1.g3dcd746-desktop and since then, turbo mode of my i7 3520M is enabled by default and it does not ...
3
votes
1answer
562 views

cpufreqd does not control temperature plus shows no output

Since my laptop (an Acer Aspire 5750G running a Gentoo Linux with a not-quite-up-to-date kernel 2.6.39-r3 (a weird wLan hardware makes the update difficult)) tends to run rather hot I am trying to ...
2
votes
3answers
2k views

How does CPU frequency work in conky?

I'm setting up conky and I would like to add the CPU frequency, but if I put ${freq_g cpu0} Ghz I get 1.2Ghz. Why is that? My CPU is 2.8Ghz.
2
votes
1answer
612 views

How to set up a Debian system (focus on 2D or console/server) with an AMD Turbo Core APU for maximum energy and computing efficiency?

I plan to set up an AMD APU system using Debian, but I cannot find hints how to achieve maximum energy efficiency and successful use of Turbo Core. In particular, the Debian Wiki HowTo on CPU ...
2
votes
1answer
565 views

CPU speed and cat /proc/cpuinfo

I use centos 6.4 64. I have old proc - CPU AMD Phenom II X4 810 (HDX810W) 2.6 GHz. However, when I execute the command cat /proc/cpuinfo I get the following: processor : 0 vendor_id : ...
2
votes
1answer
3k views

CPU fan extremely fast even with 0% CPU [closed]

I just reinstalled my operating system (Crunchbang on Debian testing), and all of a sudden the fan is running as fast as it can even with 0% CPU. The air coming out of it is cold. The only CPU ...
2
votes
1answer
5k views

Ubuntu- How do I change clock speed from terminal? [duplicate]

The title of this question pretty much says it all. What command or program do I need to run in order to change the clock speed to a specific value I want? For example, I'm looking for something like ...
2
votes
2answers
2k views

Powersave governor as default Arch

I try to change governor from "ondemand" to "powersave" like wiki says ( https://wiki.archlinux.org/index.php/CPU_Frequency_Scaling#Scaling_governors ), but everyway I want to change it, Arch always ...
2
votes
1answer
76 views

Set CPU affinity for the specific program?

How can I set CPU affinity for the specific program (say gzip) to always run on specific core or cores (core 1, for example)? I read about taskset, but can it be used before program is actually used ...
2
votes
1answer
1k views

FreeBSD CPU frequency scaling on AMD Sempron 2100

I have FreeBSD 9.0-RC3 installed on an HP Thin Client that has a Mobile AMD Sempron(tm) Processor 2100+. I am trying to get cpufreq and powerd to manage the frequency of the processor, but I'm not ...
2
votes
0answers
34 views

Suspend system instead of shutdown on CPU overheat

I have Linux Mint. The system Linux Mint is installed on, shuts down immediately on overheating. Is there anyway the system doesn't shutdown, but goes to standby state? The machine can always be ...
2
votes
0answers
28 views

Assign virtual core number to specific real core

Is there any way to assign ''linux core numbers'' to specific real cores? I'm working with an asymmetric architecture, so not all cores are the same, and I want to assign specific cores number to ...
2
votes
0answers
655 views

Disable CPU scaling with U 1404

I know there are a lot of things about this topic but I couldn't find anything not older than 4 years. As the stuff develops so fast I hope it is fine to ask again a few years later. What is ...
2
votes
0answers
214 views

CPU frequency goes back after scaling down by indicator-cpufreq, suspension and waking up

I scale down the CPU frequency by indicator-cpufreq on Ubuntu 12.04. After I suspend Ubuntu and wake it up, the CPU goes back to"on demand" (the default). I wonder if there is a way to keep the CPU ...
2
votes
0answers
278 views

Unable to reduce core frequency freebsd

I'm working on a FreeBSD project where I need to maintain the temperature of the processor below a threshold value. In order to reduce the temperature I'm trying to dynamically change the frequency of ...
2
votes
2answers
6k views

Calculating total CPU system usage in C [closed]

I found this answer on StackOverflow for calculating total CPU usage: http://stackoverflow.com/questions/1420426/calculating-cpu-usage-of-a-process-in-linux/4497769#4497769 But how do I calculate ...
1
vote
2answers
2k views

Kondemand process consumes most of my CPU

Following is the output from top: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3551 mysql 20 0 10.0g 84m 4052 S 9.4 0.1 544:39.87 mysqld 2311 root 20 0 0 ...
1
vote
2answers
153 views

Linux and CPU usage

What does it mean for a core to run at different loads in different moments? How does a 10% load differ from a 90% load? How is this number calculated, essentially?
1
vote
4answers
3k views

command to find processor speed on zlinux machine

I have the following system : $ uname -a Linux <machine-name-snip> 2.6.18-92.el5 #1 SMP Tue Apr 29 13:16:58 EDT 2008 s390x s390x s390x GNU/Linux $ cat /etc/redhat-release Red Hat Enterprise ...
1
vote
1answer
405 views

How do I add CPU frequency governors to the Linux kernel?

CPU frequency scaling in Linux is by default performed via a governor, which as far as I know is included in the kernel. So far, on PC/server Linux kernels I've only seen the userspace, powersave, ...
1
vote
1answer
674 views

Scale cpu frequency in CLI?

I am using cpufreq to scale my CPU frequency. But I do that by clicking cpufreq icon on the panel of Ubuntu 12.04. If without a mouse, how can I show and scale CPU frequency by running commands in ...
1
vote
1answer
586 views

Process priority and cpu speed

In some devices the cpu speed is dynamic, being faster when there is more load. I was wondering if it is possible to set nice level or priority of a process so that it does not influence an increase ...
1
vote
1answer
77 views

Does Powersave Mode on the CPU help at all to save power?

I use indicator-cpufreq with Cinnamon to control my CPU-usage and save power, as my battery life has been running low. So, I use indicator-cpufreq to put my CPU in powersave mode. However, I have this ...
1
vote
1answer
730 views

“rcu_preempt detected stalls on CPUs / tasks” message appears to continue

My board continues to display the message below. The terminal does not have any input. What is it with the following message, which I know? (T, g, c, q ...) What is the cause of this phenomenon? ...
1
vote
1answer
2k views

Where can I find cpu temperature and frequency without any specific command?

I want to make a shell script that runs as a daemon process and every X minutes read the temperature of every cpu core to report it later with GNU plot. And here is my question, Is there any file in ...
1
vote
0answers
189 views

RHEL 7 Still CPU Frequency Scaling

When machine is imaged with: RHEL6.x CPU speeds report full 3.3Ghz speed for all CPUs cpupowerutils is not installed RHEL7.x CPU speeds vary (shown in example below) cpupowerutils is installed ...
1
vote
0answers
55 views

Process scheduling and core allocation on big.LITTLE CPUs

Recent ARM chips, like the Qualcomm Snapdragon 810, seem to be using a hybrid architecture called "big.LITTLE" with cores of different architectures and speeds combined into one CPU. On a Linux (or ...
1
vote
0answers
89 views

CPU always at 80°C while the system is idle

My system is quite unused at the moment: %Cpu(s): 10.3 us, 3.1 sy, 0.0 ni, 85.9 id, 0.7 wa, 0.0 hi, 0.0 si, 0.0 s but still the temps sensors give me are quite high: acpitz-virtual-0 ...
1
vote
0answers
98 views

how to set or know scaling driver in linux kernel

I am trying to modify the scheduler/governor. For the same I need to know what CPUFreq Driver or scalling driver am I configured to run. 1.Where can I find what scaling driver am I configured to ...
1
vote
0answers
344 views

Is it safe to disable Frequency Scaling and CPU idle Power Management support for Real Time purposes?

I'm using a Raspberry Pi board and I would like to build a real time system. During the kernel configuration, I found the CONFIG_CPU_FREQ option, which (from the help section) allows you to change ...
1
vote
0answers
163 views

Changing CPU frequency programmatically

I have seen that standard CPU Frequency driver(comes with default package with linux kernel) can change the CPU frequency at runtime, when being used under the supervision of "Ondemand" governor. ...
1
vote
0answers
568 views

indicator-cpufreq in arch linux

I'm an Ubuntu user testing out Arch Linux. So far I'm happy. On Ubuntu I used the indicator-cpufreq applet to control power profile both on Unity and Gnome-shell. On Arch, I cannot figure out how ...
1
vote
0answers
401 views

How do you run CPU at turbo speed continuously

processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 60 model name : Intel(R) Xeon(R) CPU E3-1230 v3 @ 3.30GHz stepping : 3 cpu MHz : 3299.670 ...