Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

System mode CPU time in Linux

Posted on 2009-07-09
3
331 Views
Last Modified: 2012-05-07
Hello Experts,
I am analyzing performance on a linux server and have noticed that a majority of the CPU time is allocated to system mode execution.  Normally (ie, in Windows for me), I would start to look at whether drivers are up to date, fragmentation was an issue, etc.   My question is - is there anything to tune on a Linux system that shows a high system to user mode execution ratio?  Or, is that just the way it is and I should look elsewhere for problems?
0
Comment
Question by:markdolar
  • 2
3 Comments
 
LVL 40

Expert Comment

by:mrjoltcola
ID: 24819686
system time represents time spent in system calls (kernel space) and/or IO.
user time represents time spent in actual user code.

Could be your system is doing a lot of IO.
0
 

Author Comment

by:markdolar
ID: 24824378
Thank you for the comment.

Certainly high I/O is suspected, but the relatively low I/O wait time makes me suspect other contributors.  I'd like to follow the trail directly into system calls for some of the peaks, but I don't know how to make that connection.   Any assistance appreciated.
0
 
LVL 40

Accepted Solution

by:
mrjoltcola earned 500 total points
ID: 24824473
I would agree, there are other things besides IO that can register as system.

You can use strace to trace a given program / process.

You can also turn on system call auditing (google linux system auditing)


0

Featured Post

Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

rdate is a Linux command and the network time protocol for immediate date and time setup from another machine. The clocks are synchronized by entering rdate with the -s switch (command without switch just checks the time but does not set anything). …
How many times have you wanted to quickly do the same thing to a list but found yourself typing it again and again? I first figured out a small time saver with the up arrow to recall the last command but that can only get you so far if you have a bi…
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
Learn how to get help with Linux/Unix bash shell commands. Use help to read help documents for built in bash shell commands.: Use man to interface with the online reference manuals for shell commands.: Use man to search man pages for unknown command…

791 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question