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]):
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