76
votes
High CPU utilization but low load average
On Linux at least, the load average and CPU utilization are actually two different things. Load average is a measurement of how many tasks are waiting in a kernel run queue (not just CPU time but also ...
- 1,435
27
votes
High CPU utilization but low load average
Load is a very deceptive number. Take it with a grain of salt.
If you spawn many tasks in very quick succession which complete very quickly, the number of processes in the run queue is too small to ...
- 23.2k
25
votes
Accepted
Do CPU credits exist for c5d.large instances? And if not, why not?
CPU credits only apply to T2/T3 instances. Each T2/T3 instance accumulates some CPU credits per second and also when it's in use (i.e. not "idle") it spends these CPU credits. When it runs out of ...
- 24.3k
23
votes
Accepted
Use of CPUQuota in systemd
The Good
Your solution is the correct and should actually be quite future-proof; by using systemd to control the services cgroup settings, eg. CPUQota.
[Unit]
Description=Virtual Distributed Ethernet
...
- 346
23
votes
Accepted
How often do you restart a heavily-utilized Windows Server 2008R2 Remote Desktop Server (VM)?
Generally, I'm opposed to the idea that a Windows server should be rebooted on a regular schedule EXCEPT in relation to TS/RDS servers. We reboot ours every day. It clears up old sessions, releases in ...
- 109k
23
votes
Accepted
stress-ng: Simulate specific cpu percentages
I designed stress-ng so that one can specify 0 for the number of stressor processes to match the number of on-line CPUs, so to load each cpu at say 40%, use
stress-ng -c 0 -l 40
- 346
17
votes
How often do you restart a heavily-utilized Windows Server 2008R2 Remote Desktop Server (VM)?
Users refuse to log off instead of disconnect
Setup the appropriate group policies to auto-logoff them. You can separately control an idle timeout and logoff. That should certainly minimize some of ...
- 130k
15
votes
kswapd often uses 100% CPU when swap is in use
It seems a relatively common problem
When the problem is happening, can you check if issuing the following command stops it: echo 1 > /proc/sys/vm/drop_caches
If it works, you can schedule it as ...
- 45.5k
11
votes
Accepted
Why is my AWS instances suddenly becoming irresponsive reporting high "stolen" CPU
The t-series of instances at Amazon use a quota system for CPU usage. When you reach your quota, you start seeing your stolen percentages rise. There isn't much you can do about that, it's structural ...
- 132k
10
votes
Accepted
How to find what processes were running at a time in the past?
There are several options:
use a script which writes needed data on a regular basis to a logfile. You could use cron to write the output of ps (and other commands) every x minutes into a logfile.
...
- 391
9
votes
How to compare mainframe CPU performance?
Comparing the number of CPUs of a mainframe image isn't meaningful, most likely. Mainframes are designed to run multiple tasks at the same time, and give priority to whatever the business says is ...
- 231
9
votes
How to compare mainframe CPU performance?
Kevin mentions a number of great points, but it might help to start the analysis at a little higher level: what are the two machines and, since we're talking about Tomcat which runs in a JVM, do both ...
- 191
8
votes
CPU overloaded but no proccess is using more than 1%
On Linux, blocked processes also contribute to the load averages. The command ps -Al lists all processes. In the second column (S for State) of its output you will find the process states. Most often ...
- 333
7
votes
CPU load for high performance computing
Load average shows the queue of threads ready to run. In Linux, this includes also threads waiting for disk. It could happen that a broken NFS server could increase the load average to insane numbers. ...
- 17k
7
votes
Accepted
ZFS: arc_prune is using 100% CPU with high load average
Something is forcing ZFS to reclaim memory by shrinking ARC. To immediately solve this problem, you can try issuing
echo 1 > /proc/sys/vm/drop_caches to drop Linux pagecache only, or
echo 3 > /...
- 45.5k
6
votes
How often do you restart a heavily-utilized Windows Server 2008R2 Remote Desktop Server (VM)?
Depending on your cash, time, and the savviness of your users, another idea could be to stand up a second server. You'll still need to reboot occasionally, but you seem to be reaching the limits of a ...
- 281
6
votes
cpufreq-info differs from /proc/cpuinfo?
I'm almost convinced it your BIOS is limiting your CPUs to 1.20 GHz. In the kernel there are two values:
scaling_cur_freq which is the frequency that the cpufreq driver thinks it has requested. /proc/...
- 17.9k
6
votes
Accepted
High CPU Load on Synology by smbd
First, this seems a common problem with DS213j and DSM 5.1+. Someone reported that after a reboot, the problem went away: have you tried it?
From your top data, it seems that the CPU is busy with ...
- 45.5k
6
votes
Root user consume huge amount of CPU
If your company has a breach response process, I would invoke that now.
Otherwise:
This looks potentially malicious, I would recommend looking at it closer in /proc.
With a root privilege shell, ...
- 1,028
5
votes
How to check gpu usages on aws ec2 gpu instance?
Use: nvidia-smi -h to see the options.
Display info arguments:
Display only selected information: MEMORY,
UTILIZATION, ECC, TEMPERATURE, POWER, CLOCK,
...
- 51
5
votes
Accepted
virsh vcpu_period and vcpu_quota
quota
The optional quota element specifies the maximum allowed bandwidth(unit: microseconds). A domain with quota as any negative value indicates that the domain has infinite bandwidth, which means ...
- 66
5
votes
High CPU utilization but low load average
If the load average doesn't increase much then it just means that your hardware specs and the nature of the tasks to be processed result in a good overall throughput, avoiding them to be piled up in ...
- 13k
5
votes
Accepted
What's the advisable maximum CPU usage?
100% is totally fine. Wherever you read it damages the processor -those are idiots with no proper cooling.
Whether 100% CPU utilization is acceptable depends - on the task. Yes, the computer will get ...
- 51.4k
5
votes
Accepted
Low CPU and Memory utilization. Does that mean server is healthy?
Numbers you have posted look just fine. But it is hard to tell what else is going under the hood. If the server is doing fine - meaning response times are in acceptable range, no spikes or so, ...
- 3,927
5
votes
cpufreq-info differs from /proc/cpuinfo?
BIOS changes are the best way to guarantee peak performance but some hardware controlled frequency scaling is inevitable(thermal throttling).
Here is a post from Intel about setting CPU Frequency. ...
- 2,751
5
votes
stress-ng: Simulate specific cpu percentages
I should have used -l option
Looks like -c 1 distribute the load between all cores. Not exactly 80/4 per core, I guess because the host already runing some stuff.
stress-ng -c 1 -l 80
and -c 4 ...
- 416
5
votes
Accepted
How is RAM and CPU allocated if no manual changes are applied to an Ubuntu Server
RAM is first-come-first-serve. If userA runs 9 processes that allocate 10% of memory each, and then userB logs on, userB will see only 10% of memory left. In the event that memory is exhausted, ...
- 360
5
votes
How is RAM and CPU allocated if no manual changes are applied to an Ubuntu Server
If you need to limit memory usage on the same server, your best bet will be to either
Use two Virtual Machines, ideally KVM so that you can use the existing Ubuntu server to host the VMs. However, ...
- 1,351
5
votes
Accepted
50% Load on 2 CPU is the same that 100% Load on One CPU?
It's not quite that simple. With one thread or process that burns as much CPU as possible, it will max out at 50% CPU on a dual CPU system. Or, some systems will show it as 100% CPU, because the ...
- 8,046
5
votes
How can I monitor CPU usage and processes on Windows Server 2012 as a service over a 24 hour period?
Windows Server has a built-in tool to show performance data in real time or to collect data in logs for later review. I think that this will do exactly what you are looking for.
See this article for ...
- 633
Only top scored, non community-wiki answers of a minimum length are eligible