cpulimit

#!/bin/bash
# CPU limit of a process
#
# Variables
CPU_LIMIT=50        # Maximum percentage CPU consumption by each PID 
                    # NOTE: If your machine has one processor you can limit the percentage from 0% to 100%, which means that if you set for example 50%, your process cannot use more than 500 ms of cpu time for each second. But if your machine has four processors, percentage may vary from 0% to 400%, so setting the limit to 200% means to use no more than half of the available power.
DAEMON_INTERVAL=3   # Daemon check interval in seconds
BLACKLIST="atom|chrome" # Processes to be limited. If variable is empty (default) all violating processes are limited.


for PROCESS_1 in $BLACKLIST
do
  if [ -n "$PROCESS_1" ] # Process_1 entered
	then  

			PID_1="pidof $PROCESS_1" # Set NEW_PIDS_COMMAND variable to below command

	echo "Limit Process of: $PROCESS_1"

			cpulimit --pid "$PID_1" -b -l "$CPU_LIMIT" # Run cpulimit with selected paramters

	else

		 echo "All Processes limited to: $CPU_LIMIT"

		 PID_1="top -b -n1 -c | gawk 'NR>6 && \$9>CPU_LIMIT {print \$1}' CPU_LIMIT=$CPU_LIMIT" # Set global CPU limit
	fi


	# Search and limit violating PIDs
	while sleep $DAEMON_INTERVAL
	do
		 NEW_PIDS=$(eval "$PID_1")                                                                    # Violating PIDs
		 LIMITED_PIDS=$(ps -eo args | gawk '$1=="cpulimit" {print $3}')                                          # Already limited PIDs
		 QUEUE_PIDS=$(comm -23 <(echo "$NEW_PIDS" | sort -u) <(echo "$LIMITED_PIDS" | sort -u) | grep -v '^$')   # PIDs in queue

		 for i in $QUEUE_PIDS
		 do
			   cpulimit -p $i -l $CPU_LIMIT -z &   # Limit new violating processes
		 done
	done
done