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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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 ...
0
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3answers
20 views

How to allocate a process specific amount of CPU power? [duplicate]

I would like to allocate certain number of CPU cores to a specific process for performance improvement. How can I do this?
4
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1answer
164 views

How to sort ps output to find processes realtime priority and identify processess currently occupied running queue

How to properly identify real-time processes currently occupied CPU queue and count them using ps? I know there is a bunch of fileds like prio,rtprio,pri,nice but do not know correct to use. It seems ...
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1answer
870 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 ...
3
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0answers
35 views

How to determine how much time a process is blocked waiting for networking (socket) activity?

We are having issues with high load (top and uptime) but high CPU idle. Usually, that means high IO wait but that's also low. I believe IO wait typically does not include time a process is blocked ...
5
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3answers
48k views

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
0
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2answers
33 views

When is the page table of a process loaded in memory?

I'd like to know when is the page table of a particular process loaded in main memory by the OS? Is it when the process gets scheduled? Is the OS capable of directly loading the process page table ...
0
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0answers
7 views

How does the native_cpuid() x86 function set the Extended Processor Info and Feature Bits? [closed]

The following function from the Linux kernel is a C implementation for utilizing the CPUID call in ASM. static inline void native_cpuid(unsigned int *eax, unsigned int *ebx, ...
7
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4answers
10k views

How do I know which processors are physical cores?

I've got an Intel i7 2700k here, and I'd like to know how I can tell which processors are physical and which are virtual (ie: hyperthreading). I'm currently running a Conky script to display my CPU ...
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0answers
20 views

Marking TSC unstable due to check_tsc_sync_source failed

My dedicated server has been hanging it out (or just turning off) very often sometimes more than a day, apparently for no reason (according with the technical support department). After that, the only ...
0
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0answers
11 views

Fan starts when watching videos through browser plugins on Macbook with Arch

On a Macbook Air (2012) running Arch, after watching a show on Netflix with Google Chrome for ten or 15 minutes, the fan starts; this hardly ever happened with Mac OS. Can something be done?
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1answer
1k views

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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1answer
2k views

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 ...
1
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1answer
989 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 ...
1
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1answer
62 views

What does “cpu MHz” field mean in the /proc/cpuinfo of a hyper-threading cpu?

The CPU is a i7-3770@3.40GHz. It has 4 cores and each core has 2 threads. Here is the dmidecode output: # dmidecode -t 4 # dmidecode 2.9 SMBIOS 2.7 present. Handle 0x0042, DMI type 4, 42 bytes ...
3
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2answers
2k views

Measuring CPU %steal on VMware and Hyper-V hypervisors

For Xen Linux guests, %steal time is readily available via top and other utilities. Is it possible to get this and related metrics from within a Linux guest when running a non-Xen hypervisor such as ...
0
votes
1answer
23 views

CPU graph not functioning properly

My conky's cpu graph appears to not be functioning properly. It is just a block as per the screenshot that does not respond to actual cpu usage. Kind of annoying. I have also attached my conkyrc. I ...
0
votes
1answer
13 views

What is the threshold for top to label a process as idle

With the top command I can toggle, whether to list idle processes or not. What is the CPU usage limit for a process to show up as idle or non-idle?
0
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0answers
18 views

Fast file access for many threads doing read / write operations?

I have a disk with a lot of data on it and I want to write some code such that thousands of threads can operate on the data. Each thread would work on its own individual file. This will speed up ...
23
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4answers
20k 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.
1
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1answer
386 views

upowerd consuming 100% cpu

upowerd is consuming nearly 100% of CPU. I am currently affected by this issue on both a Lenovo Thinkpad E520 and on a desktop PC running Core i7 and Asus Z170a motherboard. Both run Kubuntu 15.10. ...
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2answers
343 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 ...
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1answer
4k views

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 ...
3
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2answers
2k views

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 ...
0
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0answers
11 views

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 ...
0
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1answer
44 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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1answer
30 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, ...
7
votes
4answers
11k 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 ...
0
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0answers
32 views

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 ...
0
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0answers
42 views

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 ...
0
votes
1answer
311 views

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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0answers
21 views

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?
1
vote
1answer
43 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 ...
0
votes
1answer
39 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?
0
votes
1answer
34 views

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 ...
19
votes
6answers
24k views

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: ...
5
votes
1answer
233 views

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 ...
11
votes
8answers
6k views

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 ...
2
votes
1answer
188 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-...
6
votes
2answers
13k views

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?
1
vote
2answers
39 views

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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vote
2answers
95 views

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. ...
3
votes
1answer
64 views

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 ...
1
vote
1answer
42 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 ...
4
votes
1answer
160 views

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 ...
0
votes
1answer
120 views

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
7k views

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 ...
0
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2answers
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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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2answers
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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 ...
0
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0answers
35 views

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 ...