Tagged Questions

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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1answer
84 views

What happens to the files when they are being decrypted?

I have the server's webroot directory mounted on a partition which is being protected with LUKS encryption. I want to know what happens to the files within when that partition is being decrypted. Does ...
3
votes
1answer
108 views

What's the correct value to base the maximum number of CPU's to sched_setaffinity to?

I have some confusion as to what's the correct value to use for the number of CPU's I can use to make a CPU_SET for a sched_setaffinity call on my system. My /proc/cpuinfo file: processor : 0 ...
10
votes
1answer
1k views

How can I monitor CPU usage by user?

I need to monitor CPU usage by users of two servers' (Ubuntu and CentOS). For example: user1 5% user2 10% ... Is there a tool similar to top or htop that can do that?
5
votes
1answer
290 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 ...
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7answers
2k 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 - 1. set up a cron-job or, 2. implement a loop with sleep in the script itself. Question: ...
1
vote
1answer
85 views

Why my cpu spend so much time on system? [closed]

top - 08:58:42 up 20 days, 8:23, 1 user, load average: 67.17, 58.94, 62.75 Tasks: 630 total, 40 running, 524 sleeping, 0 stopped, 66 zombie Cpu(s): 57.3%us, 41.6%sy, 0.0%ni, 0.0%id, 0.0%wa, ...
2
votes
1answer
252 views

Determine the intel CPU family for C compiler?

I am checking the CPU information on a Linux server, and tuning options of the Intel C compiler icc for my C code running on the server's specific architecture. I am thinking about choosing the value ...
3
votes
1answer
53 views

Is there a tool that I can use to create a diagram of my system's architecture?

I'm looking for a tool that can create both graphical files as well as text based ASCII representations of my system's CPU & motherboard architectures.
0
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1answer
103 views

When speaking about cache size of a CPU, we only need the size of the cache at the furthest level [closed]

When speaking about cache size of a CPU, do we only need to know the size of the cache at the furthest level (such as at level 3, when the cache hierachy is 3-level)? Instead of the sum of all the ...
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0answers
25 views

Limit CPU/RAM usage per user? [duplicate]

I'm running game server applications on dedicated server that I have, but I want to be able to limit the CPU/RAM/etc usage on a per-user basis to make sure one of the servers doesn't eat up more ...
2
votes
2answers
1k 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?
0
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1answer
177 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 ...
2
votes
0answers
159 views

VPS freezes every few days (rcu_sched_state detected stall on CPU x)

Background: I have an Ubuntu 12.04 (64bit) in Xen virtualization environment. 1 GB RAM, 1 processor. Every few days I get the following error message: rcu_sched_state detected stall on cpu 0 ...
1
vote
1answer
682 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
vote
1answer
141 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.
1
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2answers
89 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?
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vote
0answers
34 views

App consumes diferent %CPU if started at start-up or from prompt [closed]

I run an application in embedded system, and it needs to start at boot. However, I have a problem with it: when I execute it at boot (from rc.local script), it consumes nearly all the CPU, making the ...
2
votes
0answers
100 views

Limit CPU cycles inside of Xen

I'd like to run some minimum-expectation benchmarks on EC2, but I'm having an issue of high variability in my output data. Specifically, they keep giving me more CPU than I'm minimally entitled to, ...
2
votes
0answers
118 views

Why PowerVM LPAR CPU utilization is negative

For a specific case I compute an PowerVM LPAR CPU utilization to be a large number less than zero. I am fetching the lpar sample event using: lslparutil -r lpar -m P750 --filter "lpar_names=i5lp5" ...
0
votes
1answer
199 views

sar -P ALL command AIX 6.1

What is the meaning of - in the cpu column below? Is it average of all CPU cores? bash-3.00$ sar -P ALL 2 2 AIX tinapp1 1 6 00F6F78B4C00 11/27/13 System configuration: lcpu=4 mode=Capped 19:02:54 ...
-2
votes
3answers
74 views

applications that would benefit having a 64bit Os on a 64bit cpu with maximum of 4gb ram [closed]

I am trying to find out for which kind of applications (cpu intensive, io intensive, good mix of cpu/io apps) it is worth putting a 64 bit Os on 64 bit hardware instead of a 32 bit os where the Ram ...
1
vote
1answer
1k 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 ...
4
votes
1answer
198 views

Execution time and resources after processes that has been running for so long

This might be a basic question, but I am getting hard time finding an answer to it. I am using RHEL6. After running any process that takes significant cpu time, I get a line that tells (I guess) the ...
1
vote
2answers
149 views

Should I care for applications that increase the system Load in order to prevent overheating?

I found that my "PCI Adapter" overheats when load is above 4.0 (having 4 cores). It does NOT overheat when the load is below 4.0 (but I had an overclocked memory that was causing trouble as I explain ...
3
votes
1answer
1k views

Is my laptop's overheating issue CPU (Dual Core i5) or GPU (Nvidia 320M) related, and can I fix it in Linux Mint?

I've had the same problem in both Ubuntu 12.10 and Linux Mint 15. I've tried taking my Acer laptop apart (no mean feat for a noob like me) and cleaned and resat the GPU and CPU heatsinks and fan ...
1
vote
0answers
261 views

Why is the AESni flag missing for my i5 CPU

My CPU is reported by Intel to support the AES-NI native instructions. http://ark.intel.com/products/65707 However, /proc/cpuinfo does not list the aes flag (which is what I guess is preventing me ...
2
votes
1answer
749 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 ...
5
votes
1answer
199 views

How to monitor top applications using CPU (and IO if possible) in a graph?

I need to find what and when these applications used so much CPU (and IO if possible too). This should be in a graphic timeline like we see in GNOME System Monitor CPU History. I also want to compare ...
0
votes
2answers
493 views

How to monitor average stats of CPU and memory usage of a Solaris server using scripts?

I need to monitor average CPU and memory usage for a Solaris server. How can I automate the process using scripts to monitor daily CPU and memory usage and give it as an average over a month?
0
votes
1answer
561 views

Linux Mint CPU cores balancing and high temprature

I'm using Linux Mint. My laptop has a Corei5 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 it doesn't balance processes ...
0
votes
2answers
4k 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 ...
5
votes
2answers
5k 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 ...
1
vote
1answer
361 views

How to increase the system CPU load/utilization in Solaris 10 to test nagios?

I want to increase the system CPU load in Solaris 10 in order to test this scenario in Nagios. I'm running following command to get the CPU utitlization in Solaris: bash-3.00# sar -s 10 60 SunOS ...
5
votes
2answers
577 views

Does linux kill heavy and long running background processes after they reach some threshold?

If I start a really heavy (memory/cpu intensive) running really long running process will the OS terminate it after a period of time arbitrarily? I.e. are there any limits beyond which the OS would ...
2
votes
1answer
843 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 ...
0
votes
3answers
839 views

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 ...
3
votes
1answer
405 views

Mint fan control

I've installed Mint 15 on my Alienware m14x and can't figure out one thing. For some reason CPU overheats and fan does not respond to that. It always stays calm and quiet. How exactly I can change ...
3
votes
1answer
184 views

How to assign tasks to GPU

I have found a benchmark from computerbase.de (http://www.computerbase.de/artikel/grafikkarten/2013/intel-haswell-grafik-fuer-desktop-pcs-im-test/3/ in german) where in one case a task (here video ...
0
votes
3answers
502 views

High CPU utilization with zip command

When I am using the zip utility in Linux to compress files, CPU utilization is going to 100%. Can anybody help me why CPU utilization is so high? I'm using the command: zip file_name *.xml
5
votes
3answers
557 views

Determining the particular processor on which a process is running

I have access to an 8-core node of a Linux cluster. When logged in to the node, I can see a list of processors using this command: more /proc/cpuinfo In my 8-core node, the processors are numbered ...
4
votes
1answer
393 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 ...
5
votes
2answers
206 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 ...
9
votes
4answers
3k views

32-bit, 64-bit CPU op-mode on Linux

I'm confused. Running Fedora Linux, lscpu yields: Architecture: i686 CPU op-mode(s): 32-bit, 64-bit ... But when I try to install a 64-bit program (Chrome) I get error like: ...
4
votes
2answers
3k views

CPU usage of KVM

I have a linux host with 4 KVM linux guests. All the guest are pretty much idle, having a load of <0.1 inside the guest. Now, if I do a top on the host, each KVM process is using something about ...
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vote
3answers
310 views

Was my CPU kinda broken?

Today I've received some message from mcelog utility, Processor 3 heated above trip temperature. Throttling enabled. Please check your system cooling. Performance will be impacted It happens when I ...
3
votes
0answers
171 views

Exynos 5 DVFS or turning off cores in Ubuntu - Scaling frequency for one of the cores only (dual core) (cpufreq)

I was wondering if there is possible to scale only one of the cpu cores in the A15 in Exynos 5 ? I have tried using e.g cpufreq-set -c 1 -f 500MHz, but both cores are set to the same frequency. When ...
3
votes
1answer
168 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 ...
0
votes
0answers
90 views

Prevent Java to escalate CPU usage on Slackware64?

I use Slackware64-current on my work laptop and though I love running Slackware, sometimes it hangs on me near to the point of starting considering falling back to Windows. I develop on Java and use ...
0
votes
1answer
1k views

Limit CPU and memory usage for PHP-FPM and Nginx processes in CentOS

I want to limit CPU and memory usage for PHP-FPM and Nginx processes in CentOS. I came across following tools cpulimit cggroups memory resource locater which will more efficient and how can I ...
7
votes
6answers
7k 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 ...