silent_cpucsekk

#!/bin/bash

#Credits go to Paul Colby (http://colby.id.au), who says no rights reserved ;)
#http://colby.id.au/node/39

delay=1		# Seconds to wait before next measurement
swapthr=80	# Also hangs if swap is more full than this percent
chkrsync=1	# Turn this to 0 if you want to skip check for a running rsync. Especially with hard drives, it's not nice to load the system during rsyncing.

# Randomize delay: it's no good to finish all instances at the same time if a script launches multiple cpucsekks.
rdelay=`echo "$delay*($RANDOM/32767+0.5)"|bc -l`

if [ ! -d $HOME/.cpucsekk/ ]
then
 mkdir $HOME/.cpucsekk/
fi

# Edit this file for different CPU load levels.
if [ ! -f $HOME/.cpucsekk/silent_cpucsekk.txt ]
then
 echo "15" > $HOME/.cpucsekk/silent_cpucsekk.txt
fi

LOAD=100
CPU=(`grep '^cpu ' /proc/stat`)
unset CPU[0]                          # Discard the "cpu" prefix.
IDLEA=${CPU[4]}                        # Get the idle CPU time.
 
# Calculate the total CPU time.
TOTALA=0
for VALUE in "${CPU[@]}"; do
 let "TOTALA=$TOTALA+$VALUE"
done
 
while true; do		# While load > $cpupc%
 cpupc=`cat $HOME/.cpucsekk/silent_cpucsekk.txt`	# How low do we allow to step to the next task

 re='^[0-9]+$'
 if ! [[ $cpupc =~ $re ]] ; then
  echo "$HOME/.cpucsekk/silent_cpucsekk.txt should contain a single percentage number." >&2; exit 1
 fi

 if [[ -f /sys/block/sda/stat ]]
 then
  #osda=`cat /sys/block/sda/stat | awk '{ print($NF) }'`	# also check sda is not busy. (currently only sda is checked...)
  osda=`cat /sys/block/sda/stat | awk '{ print($11) }'`	# also check sda is not busy.

  sleep $rdelay

  #nsda=`cat /sys/block/sda/stat | awk '{ print($NF) }'`
  nsda=`cat /sys/block/sda/stat | awk '{ print($11) }'`
 
 elif [[ -f /sys/block/nvme0n1/stat ]]
 then
  osda=`cat /sys/block/nvme0n1/stat | awk '{ print($11) }'`	# also check ssd is not busy.

  sleep $rdelay

  nsda=`cat /sys/block/nvme0n1/stat | awk '{ print($11) }'`
 else
  osda=0
  nsda=0
 fi

 CPU=(`grep '^cpu ' /proc/stat`)
 unset CPU[0]                          # Discard the "cpu" prefix.
 IDLEB=${CPU[4]}                        # Get the idle CPU time.
  
 # Calculate the total CPU time.
 TOTALB=0
 for VALUE in "${CPU[@]}"; do
  let "TOTALB=$TOTALB+$VALUE"
 done
 
 let "TOTAL=$TOTALB-$TOTALA"		# Increments since last round
 #echo "$TOTAL"
 let "IDLE=$IDLEB-$IDLEA"
 let "LOAD=100*($TOTAL-$IDLE)/$TOTAL"	# Load percent since last round

# Now let's look at the swap
 swaptot=$(awk '$1~/^SwapTotal/ {print($2)}' /proc/meminfo)
 swapfr=$(awk '$1~/^SwapFree/ {print($2)}' /proc/meminfo)
 if [[ "$swaptot" =~ ^[0-9]+$ ]] && [[ "$swaptot" != "0" ]]
 then
  swappc=$((100-100*$swapfr/$swaptot))
 else
  swappc=0
 fi
 
 TOTALA=$TOTALB				# Turn this round into last round
 IDLEA=$IDLEB

# Check for running rsync
 rsyncruns="0"
 if [[ $chkrsync == "1" ]]
 then
  ps cax | grep rsync > /dev/null
  if [ $? -eq 0 ]; then
   rsyncruns="1"
  fi
 fi

# Check for other cpucsekks, to avoid simultaneous ending
# ps -C seems to output list in increasing order so we just check the first item. We can let things go if we are the first.
 allcpids=`ps -C cpucsekk -C silent_cpucsekk -o pid=|sed 's/ //g'`
 cqueuepos=`echo "$allcpids"|awk -v line=$$ '$0 == line {print NR}'`

 #if [[ $LOAD -lt $cpupc ]] ; then
 if [[ $LOAD -lt $cpupc ]] && [[ $osda == $nsda ]] && [[ $swappc -lt $swapthr ]] && [[ $rsyncruns == "0" ]] && [[ $cqueuepos == 1 ]] ; then
  break
 fi
done