The CPU (Central Processing Unit), is the chip in the computer that actually performs the operations and calculations that are done as a program runs. It is essentially what executes a program.

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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 ...
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On Ubuntu Linux, is it normal for mandb to run continuously (apparently in the background)?

I have access to a Ubuntu Linux node at my institution. The nodes are shared among the group, but typically I am the only person who uses this particular node. I am running a calculation in parallel ...
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Putting Linux processes on certain CPU cores [duplicate]

Possible Duplicate: How can I set the processor affinity of a process on Linux? Computer CPUs have many cores insde them nowadays. I have always wondered if there is a way to, when I start ...
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How to get CPU info on a vmware guest

This is a server that is running on Vmware ESXi: SERVER:/root # cat /etc/SuSE\-release SUSE Linux Enterprise Server 11 (x86_64) VERSION = 11 PATCHLEVEL = 2 ...
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CPU or RAM better in old machine?

I'm planning to use one of two old computers as a low-volume backup server. The machine will be online and files will be backed up over ssh/rsync. I will do a minimal install of Ubuntu or Debian ...
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What do the flags in /proc/cpuinfo mean?

How can I tell whether my processor has a particular feature? (64-bit instruction set, hardware-assisted virtualization, cryptographic accelerators, etc.) I know that the file /proc/cpuinfo contains ...
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Invoking CPU Stress

Looking for an app or tool to invoke CPU usage on my virtual Linux and Unix guests. I found the app "stress" from a post on Stackoverflow, but curious what the Unix/Linux crowd would recommend.
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Do I have PCLMUL instruction set support?

Here are the flags from /proc/cpuinfo: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc ...
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CPU and core usage stats

I'm running some programs on a server and I would like to know how much % cpu I'm taking up and how many cores are being utilised by my process. To clarify, the server has 16 CPUs, all quad-core. I ...
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Is it possible to limit how much CPU power a process can take?

I'm wondering, is there way to tell a process how much processor power it can take? The problem is I'm converting video with Arista (video converter) and I'm annoyed by the fan running like crazy, ...
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2answers
277 views

How to compare usage of memory by Window Managers?

I'd like to test a few window managers to see which of them takes less memory and CPU in certain time period (so is better choice for older computers). I'd like to make the tests myself (not to read a ...
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How can we use the command 'top‘ to monitor the total CPU usage and each processor usage simultaneously?

You know that we can use the command top to monitor the real-time CPU usage and toggle the result display to the per-processor view by pressing key 1. The disadvantage of it is you can only monitor ...
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VirtualBox guest: 16 CPUs detected but only 1 online

I am running VirtualBox (using the Qiime image http://qiime.org/install/virtual_box.html) The physical hardware is a 32 core machine. The virtual machine in VirtualBox has been given 16 cores. When ...
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250 views

Make effective the changes in CPU governor plugin

I'm using Debian Testing + Xfce. I added to my panel the plugin the handle the CPU governor. My problem is that the setting that I do on the plugin interface are not made effective. Maybe because I'm ...
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1answer
2k views

How to increase Xen guest CPU utilization?

My Xen dom0 is a Gentoo x64 pvops. I boot my guest Gentoo, in PV mode, system with the same kernel my dom0 uses. When I emerge in the guest system, building a CPP package, I am experiencing low CPU ...
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High CPU usage with CFS?

I asked a previous question to try and isolate the source of an increase in CPU usage when moving an application from RHEL 5 to RHEL 6. The analysis that I did for that seems to indicate that it is ...
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Isolating cause of higher CPU usage on RHEL 6 vs RHEL 5

I'm currently looking to move our system from RHEL 5 to RHEL 6, but I've run into a snag with unexpectedly high CPU usage on the RHEL 6 machines. It appears that this may be due at least in some part ...
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Hyperthread and processors Clock, Size, and Capacity

When I enable hyperthreading, CPU size and capacity decrease to about half the non-hyperthreaded value. Since most of my processes use only two cores, should I disable hyperthreading? lshw -C ...
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lshw and lscpu disagree on caches - which is right?

I am trying to find out specifics about caches (in particular which caches are shared between cores and which are not) and have stumpled onto a inconsistency. sudo lshw says *-cache:0 ...
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script for logging all the stats for a particular process

I want to monitor CPU usage, disk read/write usage for a particular process, say ./myprocess. To monitor CPU top command seems to be a nice option and for read and write iotop seems to be a handy ...
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4answers
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How to find which machines are idle on a cluster of many nodes

I run measurements on a cluster consisting of 32 nodes/machines. I do not require all nodes, only 4, for example. The problem is most of the time, the nodes are busy with other people running their ...
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1answer
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CPU governor settings

What are CPU governor settings? How can I get their values, if they're set? I have 24 vCPUs on my machine.
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How does load average work with modern CPU's?

My understanding of load average lead me to be quite shocked with my current system. The CPU in my workstation is an i7 with hyperthreading enabled, and cat /proc/cpuinfo produces 4 'cpu's. That all ...
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Is the sum of all PIDs “utime” the total system utime?

In order to measure a user's total CPU time, I'm using the "utime" field out of /proc/[pid]/stat: utime %lu Amount of time that this process has been scheduled in user mode, measured in ...
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i686 versus i486 kernel on an Intel Core i3

I had installed Debian 6 Squeeze on my laptop a couple of weeks ago. Coming from Ubuntu, I did this by downloading the hybrid i386 image and booting it off a USB drive. Now on GRUB, I'm presented ...
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eldoc makes emacs use 100% cpu

When I use eldoc, I add this to .emacs: (add-hook 'emacs-lisp-mode-hook 'turn-on-eldoc-mode) (add-hook 'lisp-interaction-mode-hook 'turn-on-eldoc-mode) (add-hook 'ielm-mode-hook ...
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464 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 ...
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Java problem - nearly looks like a virus?

I have a weird problem since about a week. When I wake up my computer from suspend, a java process starts and consumes about 170 % CPU capacity. I analyzed the java process a bit: it connects to ...
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How to find out how many cores (including emulated via HT and such) are avaliable to user?

I wonder how to get how many cores (including emulated via HT and such) are avaliable to user via bash shell-script command?
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How can I keep track of what's using the most CPU?

I use nagios to monitor my server. Once in a while I'll get a report that the CPU load is warning / critical, etc. Usually this happens at some odd hour or when I don't have the tools to immediately ...
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1answer
3k views

Why does top report the incorrect CPU usage?

I have a machine with Intel(R) Xeon(R) CPU E5520 visible as 16 logical cores (8 with HT). If I run something to eat CPU time (single threaded) top correctly reports 100% CPU usage for the process but ...
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How to identify if there is some power saving setting that powered down a processor in Linux

I have a linux server that apparently has two Intel Xeon X5670. /proc/cpuinfo shows 12 CPUs but dmidecode shows only one CPU and the other one is in the Unpopulated status like it is showing that ...
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/proc/cpuinfo “cache” category: L1, L2 or total?

When I look in /proc/cpuinfo, one of the lines tells me I have 6144 KB of cache. Is this L1 cache, L2 cache, or the sum of both of them? In any case, how do I find out how much L1 and L2 cache my ...
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How can I receive top-like CPU statistics from the shell?

I'm trying to get an accurate read of my used CPU (in percent) from top. This is the command I'm running for testing: top -n1 | awk '/Cpu\(s\):/ {print $2}' This returns: 10.7%us, Which is the ...
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What tool(s) should I use to test my hardware for errors?

Are there any Linux tools (command line, or Live CD) that will test hardware components for errors (hard drive, RAM, CPU, graphics card, buses) and show me some detailed output with wrong parts etc.?
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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 ...
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Only one CPU core is active on Fedora 16

I've upgraded from F15 to F16 and noticed that I have a problems with hardware detection. Upon loading I can see message like ... CPU#1 not responding ... on the screen. It disappears and I can ...
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2answers
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Is there a log of past threads that are now closed?

Sometimes, I have a rogue Java process which takes up 100% of my CPU and makes it jump about 30C in temperature (usually resulting in a crash if not killed). Problem is, I can never really identify ...
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How can I know which IRQ is responsible of high CPU usage

I've moved a server from one mainboard to another due a disk controller failure. Since then I've noticed that constantly a 25% of one of the cores goes always to IRQ however I haven't managed myself ...
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How to enable safeguards for CPU temperature

My desktop has a nasty habit. When I have several high intensity applications running and my CPU is at maximum usage for a period of time, the core temperature rises and my computer auto-shuts off. ...
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Limit process to one cpu core

How to limit process to one cpu core ? Something similar to ulimit or cpulimit would be nice. (Just to ensure: I do NOT want to limit percentage usage or time of execution. I want to force app (with ...
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4answers
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Why is kworker consuming so many resources on Linux 3.0.0-12-server?

Last Friday I upgraded my Ubuntu server to 11.10, which now runs with a 3.0.0-12-server kernel. Since then the overall performance has dropped dramatically. Before the upgrade the system load was ...
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How to maximize the use of computer performance Core i7 [closed]

How to maximize the use of computer performance Core i7 960 / 12GB Ram?. My operating system is Debian 6 (Linux kernel - 3.0.0-1-amd64). I think it does not work very quickly. Looking for some ways to ...
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3answers
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CPU locked at lowest frequency, cpufreqd says it won't manage it?

I have a Dell Latitude D600 running CrunchBang Statler (Debian Squeeze-based) with a 1.4GHz Pentium M. I noticed in Conky that my CPU freq is stuck at 600MHz, even when doing CPU-intensive things like ...
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Get CPU utilization stats from C program

I want to read the CPU utilization stats from a C program, I am interested in the percentage of use of CPU, steal time etc. These stats are shown in the 3rd row from the top command. I tried to parse ...
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How to find which Process is causing High CPU usage

Is there any way to find out from terminal which process is causing high CPU Usage ? It would also be useful to order processes in descending order of cpu Usage
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Is there a way to limit overall CPU consumption?

My laptop (an HP with an i3 chip) overheats like crazy every time I run a resource heavy process (like a large compilation, extracting large tarballs or ... playing Flash). I am currently looking ...
60
votes
1answer
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In Linux “top” command what are us, sy, ni, id, wa, hi, si and st (for CPU usage)?

When I issue $ top in linux, I get a result similar to this (see here). One of the lines has CPU usage information represented like this: Cpu(s): 87.3%us, 1.2%sy, 0.0%ni, 27.6%id, 0.0%wa, ...
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How to get information about word, address size, address bus size, data bus size and instruction bus size?

I was wondering how to get information about the following things from the command line in Linux: word (i.e. the size that the CPU can process at one time, which may not be the OS bit-depth), ...
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What are software and hardware interrupts, and how are they processed?

I am not sure if I understand the concept of hardware and software interrupts. If I understand correctly, the purpose of a hardware interrupt is to get some attention of the CPU, part of implementing ...