CPU assignment bash script Post: 302422956

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Top Forums Shell Programming and Scripting CPU assignment bash script Post 302422956 by mcky on Wednesday 19th of May 2010 09:50:57 PM

05-19-2010

Registered User

CPU assignment bash script

Hi guys,

I'm basically looking for some help with a bash script I've written. It's purpose is to assign process to individual CPU cores once that process hits 15% CPU usage or more. If it drops below 15%, it's unassigned again (using taskset).

My problem is that I can't think of a way to make the script check if the process is already assigned to an invidividual core, and if so to make it skip the assigning process and remove that core from the array of available cores (there is only enough cores in the array to allow each core to have two processes assigned each [there won't be more than that many processes on the machine so it won't ever go over the limit]). As it currently works, a process might be over 15% and already assigned to one CPU, but if another process' status has changed it could be moved from one CPU to another. I'd like this not to happen, so it doesn't switch processes between CPUs all the time.

Keep in mind I'm pretty basic in my knowledge of this stuff so some parts of the script might be a bit iffy as well. Any suggestions to fix other parts would be appreciated too.

This is what I have so far (for a quad core [you can see it's only for processes with ds_i in them]):

Code:

CPUS=( 1 2 3 0 1 2 3 0 )

PIDS=( `top -b -n 1 | grep ds_i | egrep '[SDR]   ( [0-9]|1[1-4]) ' | sed -e "s/^ *//" -e "s/ .*$//"` )

# Processes with 14% or less usage
for (( e = 0 ; e < ${#PIDS[@]} ; e++ ))
do
taskset -cp 0-3 ${PIDS[$e]}
chrt -o -p 0 ${PIDS[$e]}
done

unset PIDS


PIDS=( `top -b -n 1 | grep ds_i | egrep '[SDR]   ([1][5-9]|[2-9][0-9]) ' | sed -e "s/^ *//" -e "s/ .*$//"` )
# Processes with 15%+ CPU usage
for (( p = 0 ; p < ${#PIDS[@]} ; p++ ))
do
AFF=`taskset -cp ${PIDS[$p]} | sed -e "s/.* current affinity list: //"`

len=`echo $AFF | wc -c`
len=`expr $len - 1`

if [ $len -lt "2" ]
then

        if [ $AFF -lt "4" ]
        then
                for (( e = 0 ; e < ${#CPUS[@]} ; e++ ))
                do

                        if [[ $AFF == ${CPUS[$e]} ]]
                        then
                        unset CPUS[$e] #Remove used CPU from array
                        CPUS=( ${CPUS[*]} )
                        unset PIDS[$p] #Remove PID from array
                        break
                        fi
                done
        fi
fi
done

PIDS=( ${PIDS[*]} )

for (( p = 0 ; p < ${#PIDS[@]} ; p++ ))
do

taskset -cp ${CPUS[0]} ${PIDS[$p]}
chrt -f -p 59 ${PIDS[$p]}
unset CPUS[0]
CPUS=( ${CPUS[*]} )

done

mcky

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LEARN ABOUT DEBIAN

pct-scanner-script

PCT-SCANNER-SCRIPT(1)					      General Commands Manual					     PCT-SCANNER-SCRIPT(1)

NAME

       pct-scanner-script - easy scan and create merged DjVu and PDF documents for archiving

SYNOPSIS

       pct-scanner-script [--help]

DESCRIPTION

       pct-scanner-script  is  a  bash script and configuration system to easily scan documents and create a digital archiving. It can create DjVu
       PDF and JPEG outputs, in merged and individual files. It also has a configuration system where different  configurations  can  be  defined,
       making it easy to switch between configurations.

       Please use pct-scanner-script --help to find all program options, the complete help, and all examples.

       Features:
	 - auto archiving in merged and individual DjVu, PDF, and JPEG files
	 - auto and manual resume when scanning somehow fails
	 - cascading configuration system, for easy customizing
	 - easy command-line-style bash program, with useful options
	 - archiving made possible with both adf and flatbed scanners
	 - built for productivity and daily use
	 - uses bash, scanadf and other mainstream processing tools
	 - multilanguage commandline output

OPTIONS

       -h, --help, -?
	      Show summary of options, help, and examples.

DEBUGGING

       This  program  is  a  helper  script  to easy scan and automated digital document archiving for normal and adf scanners. You can debug this
       script by running it as bash -x pct-scanner-script [options]. The script is just a nice wrapper for the scanadf, DjVu and PDF tools.

SEE ALSO

       scanadf(1),

AUTHOR

       pct-scanner-script and this manual page are written by:
	      Jelle de Jong <jelledejong@powercraft.nl>.

								  March 31, 2009					     PCT-SCANNER-SCRIPT(1)