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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“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? ...
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45 views

How to distinguish between v2 and v3 of Xeon processors?

I'm trying to determine what processor my server is running. I tried looking at /proc/cpuinfo, using lshw and dmidecode. In all of them I get: Intel(R) Xeon(R) CPU E31220 @ 3.10GHz How do I ...
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4answers
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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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eldoc mode 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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47 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 ...
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32 views

Weird cpu-load pattern

I am facing a strange (and rather annoying) problem with my laptop set-up: dual boot "Windows 10" and "Linux Deepin 14.2 (based on ubuntu)" problem: starting up with linux at the beginning ...
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1k views

/proc/cpuinfo showing zero cpu clock speed

I saw an interesting issue where the cpuinfo file from /proc filesystem shows the cpu clock speed as zero. It is a physical host with no virtualization. Can someone explain to me some probable reasons ...
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22 views

High CPU usage after Version Upgrade

Not sure if is related to the version upgrade but since I have updated my Raspberry to Linux version 4.1.13+ (dc4@dc4-XPS13-9333) (gcc version 4.8.3 20140303 (prerelease) (crosstool-NG ...
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1answer
18 views

generate key for licensing purposes

I am interested to know if there is a way to allow a user of a web application to log in the application in the following way: 1) Generate a unique key (for licensing purposes) based on unique ...
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1answer
31k views

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 ...
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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 ...
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5answers
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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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69 views

Taskset does not Work Properly

When I type the command top The first row of the output is 29646 Usernam+ 20 0 7041320 1.047g 105604 S 1267 0.6 256:11.86 MATLAB As you can see, the CPU utilization is 1267%. That means, ...
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2answers
790 views

Number of cores on FreeBSD

What would the equivalent of Debian's nproc be in FreeBSD? I'm trying to include this in a bash script variable so if it could just print out the number of cores that would be fantastic.
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1answer
1k views

Should I install the AMD/Intel microcode packages when running Debian?

Should I install the AMD/Intel microcode packages when running Debian? What exactly do they do, and when should/shouldn't I install them? Why are they in non-free?
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63 views

SNMP Temperature with lm sensor

I have just managed to put in SNMP the lm sensor output. However, I have an alarm due to a fake threshold of Temperature SYSTIN (see output) nct6776-isa-0290 Adapter: ISA adapter Vcore: +1.02 ...
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7answers
25k views

Getting cpu usage same every time.

When I execute following command to get cpu usage , I get nice + user cpu usage. top -b -n1 | grep "Cpu(s)" | awk '{print $2 + $4}' Output: 14.5 Here I am getting problem is that the output ...
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187 views

Why is 'steal' time gradually increasing?

I'm tracking CPU usage on a VM on a lightly-loaded host. Everything appears to be functioning normally on all the VMs, but collectd is reporting a gradually increasing 'steal' time: The actual ...
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1answer
120 views

How to install dia on my debian8 64 cpu?

dpkg --add-architecture i386 root@hws:/home/debian8# dpkg -i /home/debian8/Downloads/dia_0.97.2-5_i386.deb Selecting previously unselected package dia. (Reading database ... 87794 files and ...
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3answers
95 views

CPU > 80% - how can I debug?

I am running a laravel application on a Ubuntu 14.04 digital ocean vps and I am using New Relic to monitor the server. I got an email alert that my CPU usage was above 80%. I logged in to New Relic ...
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3answers
18k views

So what are logical cpu cores (as opposed to physical cpu cores)?

I was googling about how I could find the number of CPUs in a machine and I found some posts but I am confused as some mentioned that you get the logical cores vs physical cores etc. So what is the ...
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111 views

Can rsync command run using multiple cpu?

I executed this command but it took long time when checking checksum. Load average was 1.00 at all times. Can rsync command run using multiple cpu? $ rsync --checksum -av -e ssh /usr/local/xxx/* ...
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Under what circumstances, if any, will the result of reading /proc/cpuinfo change?

What I understand so far is that when a program opens and reads any file under /proc/, the kernel will generate the information on the fly. In the specific case of cpuinfo most of that data is ...
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2answers
63 views

How to launch i7z_GUI?

I tried many ways to launch an application i7z_GUI on Debian, but it just won't start. I tried it both as root as shown below and as a user. su-to-root -X -c /usr/sbin/i7z_GUI gksu -u root ...
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1answer
55 views

how to get processor that thread is currently assigned to?

I've found such column in ps -elF: PSR processor that process is currently assigned to. I need something similar but for threads. ps huH p 1234 prints threads of process 1234, can I somehow add ...
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317 views

CPU Pipe Underrun Errors

Every time upon booting and then unlocking my GUI session on Kali Linux 2.0, I get another of this error in Virtual Console 1: [ 1235.586792] [drm:intel_set_cpu_fifo_underrun_reporting [i915]] ...
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2answers
28 views

What tools can I use to diagnose the exact reason for laptop slowness? And how do I use those tools?

I am running Linux Mint 17 on my laptop. When using applications (mainly Web Browsers) the machine freezes for little time periods. The CPU indicates 100% usage at such times, but this only seems to ...
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1answer
26 views

Relationship between Interface Speed and Processing times

I have a question regarding processing time delays. I want to know: is there a relationship between the rate of data packets received and their processing time at the receiving host, or is the ...
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2answers
114 views

Get cpu usage average for the last 5 seconds

I am trying to find an alternative to this command: mpstat 5 1 Even though it works as i need, but it have a delay of 5 seconds, i need something similar, but that will give me instantly the CPU ...
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2answers
3k views

How cpu works in conky

I' m trying to setup conky and I saw that I can use from cpu0 to cpu4 CPU0 ${cpu cpu0}% ${cpubar cpu0} CPU1 ${cpu cpu1}% ${cpubar cpu1} CPU2 ${cpu cpu2}% ${cpubar cpu2} CPU3 ${cpu cpu3}% ${cpubar ...
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4answers
18k views

How to check that AES-NI is supported by my CPU?

Howcan I check if my CPU supports the AES-NI instruction set under Linux/UNIX.
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764 views

Number of CPU cores versus frequency of cores in Qemu/Virtualbox

I plan to build a workstation mainly for running virtual machines. There will be dozens of virtual machines and they do not execute computationally expensive tasks. I will use mainly Qemu(with KVM ...
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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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1answer
46 views

What is the difference between opening an application from terminal Vs directly opening it?

I could open Firefox browser either by clicking FF icon on desktop or by running ~/firefox/firefox & in the terminal. What are the differences in these two ways of running? I am wondering because ...
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1answer
44 views

Hardware specs for Linux machine for cluster administration [closed]

I have just started as cluster system administrator and was asked to choose some features to get bought a personal machine to work on, and most intensive calculations will be perform in the cluster. I ...
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2answers
500 views

how to find out intel architecture family from command line

I get access to some xeon machines for checking performance. I want to find out what architecture they are using such as Haswell, Sandybridge , Ivybridge. Is there a command to find this out?
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3answers
82 views

Rebuild original file from diff files to save disk space

Every day 10GB text file is downloaded, the file is ~200 million lines and ~1% of the lines are changed the next day. I want to keep daily files as backup, but I'm trying to save disk space by using ...
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784 views

script to check cpu utilization in linux

I want a bash script that show the CPU consumption every minute and save it in a file. The output would be like this: 11/09/2015 10:00: CPU: 60% 11/09/2015 10:01: CPU: 72% 11/09/2015 10:02: CPU: 32% ...
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2answers
95 views

Optimal BIOS CPU power config for performant Hadoop?

I'm in the process of setting up a Hadoop cluster and have so far been unable to find a good answer for how to configure CPU power in the BIOS for Linux. My BIOS give a variety of options with ...
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3answers
963 views

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
606 views

Are “kernel mode” and “user mode” hardware features or software features?

I read that there are two modes called “kernel mode” and “user mode” to handle execution of processes. (Understanding the Linux Kernel, 3rd Edition.) Is that a hardware switch (kernel/user) that is ...
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13k views

Top “id” is using 50-99% of CPU

My i386 Lubuntu install is running with a constantly 100% CPU. Using top I have diagnosed "%id" as using up a lot of CPU, usually between about 50% and 99%. Why is this happening, and how can I stop ...
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1answer
47 views

Is there a brief way to view the top resource usage(CPU, memory or even bandwidth) of a program after its running?

I know I can use top to view the overall real-time CPU & Memory usage, and nload for overall real-time bandwidth usage. But I wish to view the maximum(or average) CPU, Memory, & bandwidth ...
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3answers
282 views

Store CPU utilization into CSV file

OS: Debian 8 x64 I'd like to log every 5 seconds the CPU percentage into a CSV file in the format below: YYYY-MM-DD HH:MM:SS,CPU% I'm not familiar with how to use the top program to calculate the ...
0
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1answer
294 views

Kernel panic – not syncing: Fatal machine check on current CPU

In the latest few weeks, my machine rebooted a few times with this kernel panic error. It's a fedora 21, Linux 4 machine on an AMD E-350 APU. I didn't observe any pattern. When I reboot, the BIOS ...
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426 views

Externaly limiting number of CPU cores used

I need to externally limit a process/session to a certain number of cores. Are there any other possibilities than CPU affinity (I don't like the need to specify the actual cores) and cgroups (hard to ...
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252 views

Kernel - Measuring the rate of timer interrupts

I am working on optimizing kernels of my boxes for telephony, which involves (among other things) adjusting the HZ rate and the preemption model. Initially the kernel was compiled with the default ...
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3answers
10k views

Bash script that automatically kills processes when CPU/memory usage gets too high

I have created a script that kills processes if CPU and/or memory usage hits 80%. It creates a list of killed processes when this happens. What can I do to improve it? while [ 1 ]; do echo echo ...
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1answer
231 views

cpulimit on a bash script which runs other commands

I have a bash script which runs other cpu-intensive commands . When I apply cpulimit on the bash script, the output of top shows processes for the commands inside the script still run without ...
0
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1answer
27 views

Use NVIDIA graphic card as regular resource

I don't use my graphic card anymore, but it is still laying there, idle. Is there a way I can turn it back on and use it just a regular, additional CPU/RAM for my laptop?