Is the CPU utilization percent calculated by computing 100 - idle% when using mpstat to calculate the average CPU usage? Is this correct or do I have to compute the CPU utilization in any other way? Thanks!
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What's the difference between CPU time sum and CPU time avg?
Why is the CPU time avg larger than CPU time?
Its seems you are trying to know about azure CPU calculation metrics. Please have a look.
CPU Time: The amount of CPU consumed by each app in seconds, because one of their quotas is defined in CPU minutes used by the app. Its calculated over one application uses.
CPU percentage: CPU percentage is a good indication of the overall usage across all instances. Let's say, you have 5 application these metrics calculated all of your application uses in average.
Why CPU time avg is large than CPU time?
I think in your screen shot given metrics is alright where your total CPU time is 18.05 that mean all if your apps consume this amount and each application consume on average 2.10
See the screen shot
For details you could take a look official docs
I know you can get the Resident set size from /proc/self/status, but would it be accurate percentage to divide it by the Total Memory found by /proc/meminfo ?
I want to test performance of one of my other program with different memory load like 10%, 20%, 30% etc. To generate memory load , I used stress tool.
When I execute
stress -m 1 --vm-bytes 128M
or
stress -m 1 --vm-bytes 256M
top command shows
% CPU %Memory
99 5 - 10%
Maximum 10% memory load was generating, not exceeding any more.
How to generate 20%, 30% memory load?
Is there any other tool available for generating memory load in linux
When I try to restrict CPU utilization using cpulimit, it doesn't change the CPU utilization.
cpulimit -p <pid> -l 20
Is it possible to restrict CPU utilization and memory load at the same time - like 10% CPU Utilization, 10% Memory, 10 % CPU Utilization, 50% Memory load ?
I am using Intel(R) Core(TM) i7-3770 CPU # 3.40GHz, Ubuntu 12.04.5 LTS , 2GB RAM, 8 CPU core.
There are quite a few questions here on StackOverflow explaining how to calculate process CPU utilization (e.g. this). What I don't understand is how frequency scaling affects CPU utilization calculations. It seems to me, if I follow the formula recommended (and I actually also checked top's source code and it does the same), a process running on a CPU at the lowest frequency and a process running at the highest CPU frequency for the same duration will yield identical utilization rate. But this doesn't feel right to me, especially when CPU utilization is used as a stand-in to compare power consumption.
What am I missing?
I have a quad core (with hyper threading Technology - HT)
I'm running an application which takes 270% CPU (according to TOP command)
What is the total available CPU usage? (is it 400% or 800%?)
I'm asking because according to Intel documentation, the HT can up the performance up to 30% cpu, so 800% seem to much, yeah?)
What is the relation between load averages and CPU usage?
1: 800. You have 8 cores visible to the OS - that they are not real cores (due to hyperthreading limitations) is not of concern.
2: Ever bothered reading documentation? Practically there is no relation between load average and CPU uage. Load average is "waiting processes" but that can mean they are waiting for IO, and the CPU may not be busy.