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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Debian jessie boot hangs at “Started Update UTMP about System Runlevel Changes.”

I just upgraded my MOBO and CPU on my PC, and now whenever I try and boot my debian install it hangs at [ OK ] Started Update UTMP about System Runlevel Changes. Is there an way I can boot into my ...
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800 views

Monitor CPU Registers

I'm looking for such tool, to see state of CPU registers, eax, ebx, ecx, edx. I've discovered cpuid: eax in eax ebx ecx edx 00000000 0000000d 756e6547 6c65746e 49656e69 00000001 ...
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High Idle CPU / Low CPU Load average

After removing APC (alternative php cache), I noticed that there are less pagination access and less dirty pages but in the same time: High idle CPU Very low CPU load (relatively to the time before ...
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Linux Mint CPU cores balancing and high temperature

I am using Linux Mint. My laptop has a Core i5 CPU. When I check the system monitor, it shows that the CPU 1 usage is between 90 to 100% and CPU 2,3,4 are less than 5%. Why doesn't it balance ...
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TCP/UDP socket in order to put on hold processes

I'm working on some bash scripts which will solve "The dining philosophers problem", in order to do so I created two scripts, run.sh and philosopher.sh . In run.sh I run n instances of philosopher.sh ...
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Intel Turbo Boost apparently activated for no reason?

The other day, I reinstalled my operating system (Crunchbang, fork of Debian). For some reason my fan has been running at full speed (and blowing colder-than-room-temperature air) even though I'm ...
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39 views

How to make the Windows guest machine use more the one CPU?

I do believe this question has been posted before not only here but on Linux forums as well. However I could not implement the solutions, I am probably missing something obvious. KVM Host: Fedora 23 ...
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19 views

Kernel and User space System Calls [closed]

I understand some complex internal of OSes, but I have a large gap in understanding kernel and user space. I will explain how I understand this now. First of all we have RAM for example 8GB, ...
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960 views

Elementary OS Gala using more than 100% CPU constantly

I am using ElementaryOS with the default Drivers and my Gala process is constantly using tons of CPU (sometimes more than 200%). I have looked everywhere but couldnt find a solution. I tried to ...
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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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Ubuntu guest CPU steal 99.7 %

I'm currently running a VPS which appears to have some very strange problems. Running top gives me 99.7 % CPU steal. It's always the same value and started 3 days ago. The same thing happened a while ...
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rcu_sched self-detected stall on cpu after amd driver problems

I made a mess with my VGA driver (I have a Hp 455 probook) because SDL and openGL was having issues to create instances. After some driver reinstallations I decided that was time to reboot, but ...
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Too many rcuos and rcuob processes in my VM

I am running CentOS 7.2 (3.10.0-327.18.2.el7.x86_64) as VMware guest with 2 cpu and 6 GB RAM on my Lenevo W540 iCore 7 having 32 GB RAM. I see 128 processes each for rcuos and rcuob in my VM. This ...
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CPU load and hyperthreading [duplicate]

If I have two physical cores and hyperthreading enabled, is the CPU load computed against two cores or fours? In other words, is complete load indicated by 2.0 or 4.0?
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1answer
30 views

how to monitor spinlocks

I'm wondering how I could monitor spinlocks. At my client, we have cpu soft lockup failure, for which, if I understand well, spinlock is a likely cause. Different team use that server for predictive ...
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1answer
30 views

Execute a process always and continuosly in a single CPU Core [duplicate]

I would like to execute a process, which always has to use only one of the CPU core, and continuously run on that single core only. I am using Ubuntu 14.04, How can i achieve this?
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cross comile net snmp for arm processor

i just want to cross compile net snmp for arm cortex a9 (cyclone v soc altera). can anybody tell me how to proceed step by step?in custum board my ram is 4 gb and sd card 8 gb .i want to compile full ...
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6answers
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How to know number of cores of a system in Linux?

I wanted to find out how many cores my system has. So I searched the same question in google. I got some commands such as: $ lscpu command. When I tried this command, it gave me the following result: ...
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Whats the history behind the fork bomb?

I have read other questions about its work and other things that Fork bombs operate both by consuming CPU time in the process of forking, and by saturating the operating system's process table. A ...
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cron Vs. sleep - which is the better one in terms of efficient cpu/memory utilization?

The Case: I need to run some commands/script at certain intervals of time and for this I have two options: set up a cron-job implement a loop with sleep in the script itself. Question: Which is ...
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1answer
105 views

CentOS vmtoolsd usage 100%

I am new to CentOS and VirtualBox. I installed CentOS 7 on VirtualBox but see the CPU usage at 100% by vmtoolsd. I tried multiple ways to bring it down e.g. by doing "lodctr /R" and removing open-...
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Is there a way to dump a CPU's CPUID information?

I'm familiar with lshw, /proc/cpuinfo, etc. But is there a method for getting at a CPU's CPUID opcode?
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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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Is this “Hardware Error” when using Matlab in Fedora really a hardware problem or could it be software?

I often found the following problem when I using Matlab 2012 in Fedora 20, during or after fft calculation or plot figures. The following is the error massage: [ 635.157606] mce: [Hardware Error]: ...
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What is the meaning of Tasks and Running in htop screen?

On my computer it shows Tasks 314; 24 running What do these numbers mean? Is 1 Task = 1 process? Why isn't the number of running tasks = number of CPUs then? (I have more than 24 CPUs) edit. ...
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How does the kernel assign cpu ids to physical cores?

One may find a lot of info about how to inspect physical cores layout in a running linux system, but I'm wondering how the physical cores are assigned a cpu id in the first place. After experiencing ...
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37 views

Control fans of Samsung NP900X3E

I have a Samsung NP900X3E laptop and I would like to control the fans as one of them is making weird noise. I'm running Ubuntu 14.04.4 LTS with "Linux laptop 3.13.0-85-generic #129-Ubuntu SMP Thu Mar ...
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Why does my cpu never get past 60-70% cpu usage? Where is the bottleneck?

In my CPU graph thingy, I have noticed recently that when compiling stuff I can never seem to reach 100% usage, it just keeps bobbing up and down around 60-70% max. Example: In contrast, this graph ...
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Archlinux laptop overheating

I have a Samsung laptop and installed Archlinux on it. At first everything was fine, I was even surprised at how nice everything was, no driver problems, everything went smooth. I could watch videos ...
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4answers
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kswapd0 takes 99% to 100% CPU in RHEL 6.3

I have 5 systems on which I have just installed RHEL6. System configuration is CPU-i7 HDD-500 GB RAM-2 GB Swap- 4 GB I have installed the same software's and all the configuration as per ...
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Can someone please explain the relation of CPU bottleneck on AIX regarding lcpu and r?

# vmstat 60 2 System configuration: lcpu=12 mem=46080MB ent=1.10 kthr memory page faults cpu ----- ----------- ------------------------ ------------...
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Keep CPU busy at certain percent (to prevent CPU buzzing frequency noises) [closed]

On Dell Inspiron 7559 there is electric buzzing from beneath the keyboard that changes frequency when I touch the touchpad. However, if the CPU is busy I hear no buzzing as the frequency gets out of ...
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Linux:how java applications having 1000 threads are managed by 2 CPU's os?

Linux: 2CPU's, 16gb ram Let's say, for example, tomcat having 1000 threads. How this application threads will be shared between two CPU's, and what is the value of run queue length? In my case when ...
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Understanding top and load average

I'm observing a high load average on a certain machine (about 9) in all three load fields. I understand load as the number of processes in state "run" / currently desiring CPU time. Am I correct at ...
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Linux: Relation between run queue length and load average [duplicate]

Is there any relation between run queue length and load average?. references appreciated
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What happens when an application is started with the Linux OS [closed]

Assuming os:Linux with 14gb ram, 2 CPU's with 2.50GHz scenarios after launching how many processes will be created and where? if application wants's create 1000 threads, then who will create what ...
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1answer
21 views

How to add a virtual core to Linux system

Here a virtual core means another CPU core that does not exist physically but can exist just as another core and can be assigned processes naturally by the system. Is it even possible to do this? ...
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1answer
46 views

Process running in only one processor

I have a 40 v core machine in which a java process running. I can see that this process is running in cpu6 all the time. $watch ps -o pid,psr,comm -p 4076 Every 2.0s: ps -o pid,psr,comm -p 4076 ...
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2answers
207 views

Supervisord at 99% cpu usage

I've installed supervisord using: sudo apt-get install supervisor on my Ubuntu 14.04 server as per the instructions in the Laravel documentation. I've noticed that the supervisorctl process on my ...
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diabling cpu cores on quad core processor on linux

I want to disable 3 CPU cores and run my processor on a single core. I have used command:maxcpus=1. But after this I executed this command ls /sys/devices/system/cpu. It still shows cpu0,cpu1,cpu2,...
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top command shows dnss running at 290%

We're running software on a CentOS 6.2 virtual machine and it's been crashing quite a lot lately and keeps running slow. I checked the RAM usage, but that's only using 4GB to 5GB of the available 9GB....
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How to limit coredump CPU usage?

I have some process (test) which runs on my machine. Sometimes it crashes and a core dump is generated. Whilst the core dump is being written, the machine is completely frozen (even the mouse pointer ...
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1answer
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Why is 64bit Ubuntu running Slower? [closed]

I have 2 mostly identical machines, and Acer and a Lenovo, both with Intel Atom 230 CPU @ 1.60GHz and 1GB of DDR2 RAM. The acer has a fresh install of 64Bit Ubuntu 14.04 LTS while the Lenovo has the ...
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3answers
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How can I start a process using cpulimit?

I am trying to use cpulimit for testing an app I'm developing under low resource conditions, and I need the process to start under the influence of cpulimit. It is not sufficient to start the program ...
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70 views

What do the benchmarks in HardInfo mean?

The program hardinfo is included by default with Lubuntu as a system profiler. It can run 6 different types of benchmarks: -CPU Blowfish -CPU Cryptohash -CPU Fibonacci -CPU N-Queens -FPU FFT -...
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Is there any command that limits the use of cpu resources by percentage?

So far I've been using nice -n 10, but that's just sets the priority of the command I want to run low, but if there's no other process running at that time the command will take all the remaining cpu ...
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Gnome 3 on openSuse 42.1: Seemingly Random Commands Causing High CPU Usage

I am experiencing intense cycles of high CPU usage on my openSuse laptop. I have noticed my browser intermittently freezing up (and my fan speeding up) and I checked htop and this is what it looks ...
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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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using cpu.cfs_quota_us and cpu.cfs_period_us to limit CPU usage

There are 32 cores in a system (2 cpus each 16 cores) and I want to limit a user to use only 4 cores (100% usage for that 4 cores). There are two kernel parameter for that according to the manuals: ...
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Understanding the top command output on an ARM multicore computer

Ran the top command to check CPU performances and memory usage on the New RPi3 while running a browser. Since we have a 4× ARM Cortex-A53, 1.2GHz, how should I read the result? $ top Mem: 327132K ...