Script to list processes taking more than 10% of CPU time

linuxkid12 · 04-19-2013, 08:37 AM

Hi,
I'm trying to write a script that lists all processes taking more than 10% of CPU time. I have no idea where to start other than ps aux lists all processes. How do i sort it so that it only lists those over 10%?

cliffordw · 04-19-2013, 08:46 AM

ps aux|awk '{if ($3 > 10) {print;}}'

linuxkid12 · 04-19-2013, 08:52 AM

So if i want to put the results in a text file i do:

ps aux | awk '{$3 > 10}' > example.txt

Or do i need more??

millgates · 04-19-2013, 08:58 AM

it's either

Code:

ps aux | awk '{if($3 > 10) print}' > example.txt

or

Code:

ps aux | awk '$3 > 10 {print}' > example.txt

or, using the fact that the default action in awk is print, even

Code:

ps aux | awk '$3 > 10' > example.txt

linuxkid12 · 04-19-2013, 09:39 AM

thanks, how would i lower the priority of processes over 10%? renice?

shivaa · 04-19-2013, 09:56 AM

Memory consumption keep changing for processes. At some instance that could be more than 10% but on next moment that could be less than 10%.

Second thing, you can check memory consumption by variaous processs using top cmd, and that need to be stopped using key like q. So it's not easy to put the top command in script and capture it output in respect of memory consumption. Also did you realise, how many times or how your script will execute to check mem. consumption by various processes?

However, I would suggest you to use top command only whenever you need to check high mem. consuming processes.

On the other hand if you want to check using ps, then try this:

Code:

ps -eo pmem,pcpu,pid | sort -nr -k2

David the H. · 04-21-2013, 01:09 PM

No need to use sort, which may end up putting the header line in the wrong place. ps can do that for you too:

Code:

ps -eo pmem,pcpu,pid k -pcpu

unSpawn · 04-21-2013, 07:06 PM

Quote:

Originally Posted by David the H.

No need to use sort, which may end up putting the header line in the wrong place.

Why would you want a header if you're not using it?

Code:

ps --noheaders -eo pmem,pcpu,pid k -pcpu

David the H. · 04-23-2013, 08:53 AM

I didn't think to add that when I posted, but I did think of it later. So it was going to go into my next comment, if nobody brought it up.

jpollard · 04-23-2013, 02:37 PM

Also, if your system is using cgroups for interactive scheduling, renice doesn't really work.

What happens is that the cgroup does global scheduling, the nice values then schedule within a single cgroup. So changing the nice value will only affect the scheduling of the processes within that single cgroup, and if the other processes are I/O bound, the reniced process will still get the same CPU attention.

It doesn't matter if what you are trying to do is give a specific process more time by reducing the priority of other processes (those not in the same cgroup as the desired process). Even increasing the scheduling priority of a specific process has no effect.