In order to monitor the CPU usage in an AIX server I'm using the following script that is executed every 10 mins.

lparstat 2 10 > cpu
usage=$(tail -10 cpu | awk 'BEGIN {sum=0;} {sum+=$4} END{print int(100-sum/10)}')

if [[ $usage -ge 90 ]]; then
# mail the error and cpu file to admin
# displaying this for testing purposes
echo "CPU usage off the charts!!!"
cat cpu

However, in case the CPU usage is above 90% I need to list the top 5 Processes that are using the CPU.

How do I achieve this?

3 Answers 3


You can list the top 5 in a fairly readable way by limiting the columns, sorting them with the highest CPU usage first, and then truncating to the first 5 (using head -6, since we also want to include the headers):

ps -eo pcpu,pid,args | sort -k 1 -r | head -6

The output looks something like this:

 2.0 30531 -bash
 0.0 30673 head -6
 0.0 30672 sort -k 1 -r
 0.0 30671 ps -eo pcpu,pid,args
 0.0 30670 [flush-253:0]

You might also want to look into GNU top's batch mode (-b).

  • Unfortunately in the AIX system that I'm uing top is unavailable and has topas. ps -eo pcpu,pid,args | sort -rk1 | head -6 does give the output, but the result doesn't match with the result of topas.
    – debal
    Commented Oct 10, 2013 at 8:15
  • @debal Why must the result match topas?
    – Chris Down
    Commented Oct 10, 2013 at 8:16
  • both these commands tend to do the same thing, wouldn't it be surprising if the two results don't match? topas is giving a realtime view of the CPU usage, ps -eo pcpu,pid,args | sort -rk1 | head -6 is giving for a particular point of time, so at that instance it only makes sense if both these commands provide the same result. Which is not the case.
    – debal
    Commented Oct 10, 2013 at 8:20
  • That's not exactly the contrast point -- ps gives you a weird process lifetime vs. CPU seconds which is not necessarily indicative of what's causing high CPU "recently". topas, like top, gives you the % over a much short reasonable that is intuitively usually what people want.
    – covener
    Commented Apr 3, 2017 at 20:39

For a deep dive, the best course of action here is to run

tprof -skex sleep 10

which will give you a report detailing the processes using high CPU, then drill down into usage by function and shared libraries.


you can use below command it will match with topas output

ps -ef | egrep -v "STIME|$LOGNAME" | sort +3 -r | head -n 15

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