Script to match /proc/PID data with jstack

threadwatch.sh

#!/bin/bash

PID=$1
CPUFILE=/tmp/cpu-$PID-0
LASTFILE=/tmp/cpu-$PID-1
>$LASTFILE

function cleanup { rm  $CPUFILE $LASTFILE ; }
trap cleanup EXIT

cd /proc/${PID}/task/

while :
do

    echo
    for TID in *
    do
      CPU=$(grep se.sum_exec_runtime $TID/sched ) 2>/dev/null
      [ "$CPU" = "" ] || echo $TID $CPU
    done | sed 's/[a-z_\.]* : //' | sort -g > $CPUFILE

    LINE=$(join $LASTFILE $CPUFILE | while read TID LAST CPU
    do
      TICK=$(echo $CPU - $LAST | bc -q)
      [ "$TICK" = "0" ] || echo $TICK $TID
    done | sed 's/^\./0./' | sort -gr | head -20 | sed 's/^\(.*\) \(.*\)$/\2=\1/' )
    cp $CPUFILE $LASTFILE

    echo $(date +'%Y-%m-%d %H:%M:%S'):$PID: $LINE

    TOP=$(printf '%x' $(echo $LINE | cut -d= -f1 ))
    jstack $PID | awk "BEGIN { found=0 } /nid=0x$TOP/ { found=1; } /^$/ { found=0;} { if (found==1) print \$0 ; } "

    sleep 2

done