config: Updates for distributed gem5 simulations

7 files changed, 575 insertions, 319 deletions

diff --git a/configs/common/FSConfig.py b/configs/common/FSConfig.py
index 0f63ec9e7..004d06d55 100644
--- a/configs/common/FSConfig.py
+++ b/configs/common/FSConfig.py
@@ -654,3 +654,39 @@ def makeDualRoot(full_system, testSystem, driveSystem, dumpfile):
         self.etherlink.dump = Parent.etherdump
 
     return self
+
+
+def makeDistRoot(testSystem,
+                 rank,
+                 size,
+                 server_name,
+                 server_port,
+                 sync_repeat,
+                 sync_start,
+                 linkspeed,
+                 linkdelay,
+                 dumpfile):
+    self = Root(full_system = True)
+    self.testsys = testSystem
+
+    self.etherlink = DistEtherLink(speed = linkspeed,
+                                   delay = linkdelay,
+                                   dist_rank = rank,
+                                   dist_size = size,
+                                   server_name = server_name,
+                                   server_port = server_port,
+                                   sync_start = sync_start,
+                                   sync_repeat = sync_repeat)
+
+    if hasattr(testSystem, 'realview'):
+        self.etherlink.int0 = Parent.testsys.realview.ethernet.interface
+    elif hasattr(testSystem, 'tsunami'):
+        self.etherlink.int0 = Parent.testsys.tsunami.ethernet.interface
+    else:
+        fatal("Don't know how to connect DistEtherLink to this system")
+
+    if dumpfile:
+        self.etherdump = EtherDump(file=dumpfile)
+        self.etherlink.dump = Parent.etherdump
+
+    return self
diff --git a/configs/common/Options.py b/configs/common/Options.py
index 45be8e2f8..d5671f311 100644
--- a/configs/common/Options.py
+++ b/configs/common/Options.py
@@ -297,10 +297,41 @@ def addFSOptions(parser):
     # Benchmark options
     parser.add_option("--dual", action="store_true",
                       help="Simulate two systems attached with an ethernet link")
+    parser.add_option("--dist", action="store_true",
+                      help="Parallel distributed gem5 simulation.")
+    parser.add_option("--is-switch", action="store_true",
+                      help="Select the network switch simulator process for a"\
+                      "distributed gem5 run")
+    parser.add_option("--dist-rank", default=0, action="store", type="int",
+                      help="Rank of this system within the dist gem5 run.")
+    parser.add_option("--dist-size", default=0, action="store", type="int",
+                      help="Number of gem5 processes within the dist gem5 run.")
+    parser.add_option("--dist-server-name",
+                      default="127.0.0.1",
+                      action="store", type="string",
+                      help="Name of the message server host\nDEFAULT: localhost")
+    parser.add_option("--dist-server-port",
+                      default=2200,
+                      action="store", type="int",
+                      help="Message server listen port\nDEFAULT: 2200")
+    parser.add_option("--dist-sync-repeat",
+                      default="0us",
+                      action="store", type="string",
+                      help="Repeat interval for synchronisation barriers among dist-gem5 processes\nDEFAULT: --ethernet-linkdelay")
+    parser.add_option("--dist-sync-start",
+                      default="5200000000000t",
+                      action="store", type="string",
+                      help="Time to schedule the first dist synchronisation barrier\nDEFAULT:5200000000000t")
     parser.add_option("-b", "--benchmark", action="store", type="string",
                       dest="benchmark",
                       help="Specify the benchmark to run. Available benchmarks: %s"\
                       % DefinedBenchmarks)
+    parser.add_option("--ethernet-linkspeed", default="10Gbps",
+                        action="store", type="string",
+                        help="Link speed in bps\nDEFAULT: 10Gbps")
+    parser.add_option("--ethernet-linkdelay", default="10us",
+                      action="store", type="string",
+                      help="Link delay in seconds\nDEFAULT: 10us")
 
     # Metafile options
     parser.add_option("--etherdump", action="store", type="string", dest="etherdump",
diff --git a/configs/example/fs.py b/configs/example/fs.py
index dddb2ea3c..6ee969a6e 100644
--- a/configs/example/fs.py
+++ b/configs/example/fs.py
@@ -340,6 +340,18 @@ test_sys = build_test_system(np)
 if len(bm) == 2:
     drive_sys = build_drive_system(np)
     root = makeDualRoot(True, test_sys, drive_sys, options.etherdump)
+elif len(bm) == 1 and options.dist:
+    # This system is part of a dist-gem5 simulation
+    root = makeDistRoot(test_sys,
+                        options.dist_rank,
+                        options.dist_size,
+                        options.dist_server_name,
+                        options.dist_server_port,
+                        options.dist_sync_repeat,
+                        options.dist_sync_start,
+                        options.ethernet_linkspeed,
+                        options.ethernet_linkdelay,
+                        options.etherdump);
 elif len(bm) == 1:
     root = Root(full_system=True, system=test_sys)
 else:
diff --git a/util/dist/gem5-dist.sh b/util/dist/gem5-dist.sh
new file mode 100755
index 000000000..8fa799acc
--- /dev/null
+++ b/util/dist/gem5-dist.sh
@@ -0,0 +1,385 @@
+#! /bin/bash
+
+#
+# Copyright (c) 2015 ARM Limited
+# All rights reserved
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Copyright (c) 2015 University of Illinois Urbana Champaign
+# All rights reserved
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Gabor Dozsa
+#          Mohammad Alian
+
+
+# This is a wrapper script to run a dist gem5 simulations.
+# See the usage_func() below for hints on how to use it. Also,
+# there are some examples in the util/dist directory (e.g.
+# see util/dist/test-2nodes-AArch64.sh)
+#
+#
+# Allocated hosts/cores are assumed to be listed in the LSB_MCPU_HOSTS
+# environment variable (which is what LSF does by default).
+# E.g. LSB_MCPU_HOSTS=\"hname1 2 hname2 4\" means we have altogether 6 slots
+# allocated to launch the gem5 processes, 2 of them are on host hname1
+# and 4 of them are on host hname2.
+# If LSB_MCPU_HOSTS environment variable is not defined then we launch all
+# processes on the localhost.
+#
+# Each gem5 process are passed in a unique rank ID [0..N-1] via the kernel
+# boot params. The total number of gem5 processes is also passed in.
+# These values can be used in the boot script to configure the MAC/IP
+# addresses - among other things (see util/dist/bootscript.rcS).
+#
+# Each gem5 process will create an m5out.$GEM5_RANK directory for
+# the usual output files. Furthermore, there will be a separate log file
+# for each ssh session (we use ssh to start gem5 processes) and one for
+# the server. These are called log.$GEM5_RANK and log.switch.
+#
+
+
+# print help
+usage_func ()
+{
+    echo "Usage:$0 [-debug] [-n nnodes] [-r rundir] [-c ckptdir] [-p port] [-sw switch]  [--sw-args sw_args] [-fs fullsystem]  [--fs-args fs_args] [--cf-args conf_args] [--m5-args m5_args] -x gem5_exe "
+    echo "     -debug    : debug mode (start gem5 in gdb)"
+    echo "     nnodes    : number of gem5 processes"
+    echo "     rundir    : run simulation under this path. If not specified, current dir will be used"
+    echo "     ckptdir   : dump/restore checkpoints to/from this path. If not specified, current dir will be used"
+
+    echo "     fullsystem: fullsystem config file"
+    echo "     fs_args   : fullsystem config specific argument list: arg1 arg2 ..."
+    echo "     port      : switch listen port"
+    echo "     switch    : switch config file"
+    echo "     sw_args   : switch config specific argument list: arg1 arg2 ..."
+    echo "     conf_args : common (for both fullsystem and switch) config argument list: arg1 arg2 ..."
+    echo "     gem5_exe  : gem5 executable (full path required)"
+    echo "     m5_args   : common m5 argument list (e.g. debug flags): arg1 arg2 ..."
+    echo "Note: if no LSF slots allocation is found all proceses are launched on the localhost."
+}
+
+# Process (optional) command line options
+FS_ARGS=" "
+SW_ARGS=" "
+CF_ARGS=" "
+M5_ARGS=" "
+while (($# > 0))
+do
+    case "x$1" in
+        x-debug)
+            GEM5_DEBUG="-debug"
+            shift 1
+            ;;
+        x-n|x-nodes)
+            NNODES=$2
+            shift 2
+            ;;
+        x-r|x-rundir)
+            RUN_DIR=$2
+            shift 2
+            ;;
+        x-c|x-ckptdir)
+            CKPT_DIR=$2
+            shift 2
+            ;;
+        x-p|x-port)
+            SW_PORT=$2
+            shift 2
+            ;;
+        x-s|x-switch)
+            SW_CONFIG=$2
+            shift 2
+            ;;
+	x--sw-args)
+	    CUR_ARGS="SW_ARGS"
+	    shift 1
+	    ;;
+        x-f|x-fullsystem)
+            FS_CONFIG=$2
+            shift 2
+            ;;
+	x--fs-args)
+	    CUR_ARGS="FS_ARGS"
+	    shift 1
+	    ;;
+	x--cf-args)
+	    CUR_ARGS="CF_ARGS"
+	    shift 1
+	    ;;
+	x--m5-args)
+	    CUR_ARGS="M5_ARGS"
+	    shift 1
+	    ;;
+	x-x)
+	    GEM5_EXE=$2
+	    shift 2
+	    ;;
+	x-*)
+	    [ -n "$CUR_ARGS" ] || { echo "Unexpected arg: $1"; usage_func; exit -1; }
+	    case "x$2" in
+		x-*|x)
+		    eval $CUR_ARGS=\"${!CUR_ARGS} $1\"
+		    shift 1
+		    ;;
+		*)
+		    eval $CUR_ARGS=\"${!CUR_ARGS} $1 $2\"
+		    shift 2
+		    ;;
+	    esac
+	    ;;
+        *)
+            echo "Unknown arg: $1"
+	    usage_func
+	    exit 1
+            ;;
+    esac
+done
+
+# Default values to use (in case they are not defined as command line options)
+DEFAULT_FS_CONFIG=$M5_PATH/configs/example/fs.py
+DEFAULT_SW_CONFIG=$M5_PATH/configs/example/sw.py
+DEFAULT_SW_PORT=2200
+
+[ -z "$FS_CONFIG" ] && FS_CONFIG=$DEFAULT_FS_CONFIG
+[ -z "$SW_CONFIG" ] && SW_CONFIG=$DEFAULT_SW_CONFIG
+[ -z "$SW_PORT" ] && SW_PORT=$DEFAULT_SW_PORT
+[ -z "$NNODES" ] && NNODES=2
+[ -z "$RUN_DIR" ] && RUN_DIR=$(pwd)
+[ -z "$CKPT_DIR" ] && CKPT_DIR=$(pwd)
+
+#  Check if all the executables we need exist
+[ -f "$FS_CONFIG" ] || { echo "FS config ${FS_CONFIG} not found"; exit 1; }
+[ -f "$SW_CONFIG" ] || { echo "Switch config ${SW_CONFIG} not found"; exit 1; }
+[ -x "$GEM5_EXE" ]   || { echo "Executable ${GEM5_EXE} not found"; exit 1; }
+# make sure that RUN_DIR exists
+mkdir -p $RUN_DIR > /dev/null 2>&1
+
+declare -a SSH_PIDS
+declare -a HOSTS
+declare -a NCORES
+
+# Find out which cluster hosts/slots are allocated or
+# use localhost if there is no LSF allocation.
+# We assume that allocated slots are listed in the LSB_MCPU_HOSTS
+# environment variable in the form:
+# host1 nslots1 host2 nslots2 ...
+# (This is what LSF does by default.)
+NH=0
+[ "x$LSB_MCPU_HOSTS" != "x" ] || LSB_MCPU_HOSTS="127.0.0.1 $NNODES"
+host=""
+for hc in $LSB_MCPU_HOSTS
+do
+    if [ "x$host" == "x" ]
+    then
+        host=$hc
+        HOSTS+=($hc)
+    else
+        NCORES+=($hc)
+        ((NH+=hc))
+        host=""
+    fi
+done
+((NNODES==NH)) || { echo "(E) Number of cluster slots ($NH) and gem5 instances ($N) differ"; exit -1; }
+
+# function to clean up and abort if something goes wrong
+abort_func ()
+{
+    echo
+    echo "KILLED $(date)"
+    # Try to Kill the server first. That should trigger an exit for all connected
+    # gem5 processes.
+    [ "x$SW_PID" != "x" ] && kill $SW_PID 2>/dev/null
+    sleep 20
+    # (try to) kill gem5 processes - just in case something went wrong with the
+    # server triggered exit
+    bname=$(basename $GEM5_EXE)
+    killall -q -s SIGKILL $bname
+    for h in ${HOSTS[@]}
+    do
+	ssh $h killall -q -s SIGKILL $bname
+    done
+    sleep 5
+    # kill the watchdog
+    [ "x$WATCHDOG_PID" != "x" ] && kill $WATCHDOG_PID 2>/dev/null
+    exit -1
+}
+
+# We need a watchdog to trigger full clean up if a gem5 process dies
+watchdog_func ()
+{
+    while true
+    do
+        sleep 30
+        ((NDEAD=0))
+        for p in ${SSH_PIDS[*]}
+        do
+            kill -0 $p 2>/dev/null || ((NDEAD+=1))
+        done
+        kill -0 $SW_PID || ((NDEAD+=1))
+        if ((NDEAD>0))
+        then
+            # we may be in the middle of an orderly termination,
+            # give it some time to complete before reporting abort
+            sleep 60
+            echo -n "(I) (some) gem5 process(es) exited"
+            abort_func
+        fi
+    done
+}
+
+# This function launches the gem5 processes. The only purpose is to enable
+# launching gem5 processes under gdb control for debugging
+start_func ()
+{
+      local N=$1
+      local HOST=$2
+      local ENV_ARGS=$3
+      shift 3
+      if [ "x$GEM5_DEBUG" != "x" ]
+      then
+	      echo "DEBUG starting terminal..."
+	      MY_ARGS="$@"
+	      xterm -e "gdb --args $MY_ARGS" &
+      else
+        ssh $HOST $ENV_ARGS "$@" &> $RUN_DIR/log.$N &
+      fi
+}
+
+# block till the gem5 process starts
+connected ()
+{
+    FILE=$1
+    STRING=$2
+    echo -n "waiting for $3 to start "
+    while : ;
+    do
+        kill -0 $4 || { echo "Failed to start $3"; exit -1; }
+        [[ -f "$FILE" ]] &&                                                   \
+        grep -q "$STRING" "$FILE" &&                                          \
+        echo -e "\nnode #$3 started" &&                                       \
+        break
+
+        sleep 2
+        echo -n "."
+    done
+}
+
+# Trigger full clean up in case we are being killed by external signal
+trap 'abort_func' INT TERM
+
+# env args to be passed explicitly to gem5 processes started via ssh
+ENV_ARGS="LD_LIBRARY_PATH=$LD_LIBRARY_PATH M5_PATH=$M5_PATH"
+
+#cleanup log files before starting gem5 processes
+rm $RUN_DIR/log.switch > /dev/null 2>&1
+
+# make sure that CKPT_DIR exists
+mkdir -p $CKPT_DIR/m5out.switch > /dev/null 2>&1
+# launch switch gem5
+SW_HOST=${HOSTS[0]}
+echo "launch switch gem5 process on $SW_HOST ..."
+start_func "switch" $SW_HOST "$ENV_ARGS" $GEM5_EXE -d $RUN_DIR/m5out.switch   \
+          $M5_ARGS                                                            \
+          $SW_CONFIG                                                          \
+          $SW_ARGS                                                            \
+          $CF_ARGS                                                            \
+          --checkpoint-dir=$CKPT_DIR/m5out.switch                             \
+          --is-switch                                                         \
+          --dist-size=$NNODES                                                 \
+          --dist-server-port=$SW_PORT
+SW_PID=$!
+
+# block here till switch process starts
+connected $RUN_DIR/log.switch "tcp_iface listening on port" "switch" $SW_PID
+LINE=$(grep -r "tcp_iface listening on port" $RUN_DIR/log.switch)
+
+IFS=' ' read -ra ADDR <<< "$LINE"
+# actual port that switch is listening on may be different
+# from what we specified if the port was busy
+SW_PORT=${ADDR[5]}
+
+# Now launch all the gem5 processes with ssh.
+echo "START $(date)"
+n=0
+for ((i=0; i < ${#HOSTS[@]}; i++))
+do
+    h=${HOSTS[$i]}
+    for ((j=0; j < ${NCORES[i]}; j++))
+    do
+        #cleanup log files before starting gem5 processes
+        rm $RUN_DIR/log.$n > /dev/null 2>&1
+        # make sure that CKPT_DIR exists
+        mkdir -p $CKPT_DIR/m5out.$n > /dev/null 2>&1
+	    echo "starting gem5 on $h ..."
+	    start_func $n $h "$ENV_ARGS" $GEM5_EXE -d $RUN_DIR/m5out.$n       \
+                       $M5_ARGS                                               \
+                       $FS_CONFIG                                             \
+                       $FS_ARGS                                               \
+                       $CF_ARGS                                               \
+                       --checkpoint-dir=$CKPT_DIR/m5out.$n                    \
+	               --dist                                                 \
+	               --dist-rank=$n                                         \
+	               --dist-size=$NNODES                                    \
+                       --dist-server-name=${HOSTS[0]}                         \
+                       --dist-server-port=$SW_PORT
+	    SSH_PIDS[$n]=$!
+	((n+=1))
+    done
+done
+
+# Wait here if it is a debug session
+[ "x$GEM5_DEBUG" == "x" ] || {  echo "DEBUG session"; wait $SW_PID; exit -1; }
+
+# start watchdog to trigger complete abort (after a grace period) if any
+# gem5 process dies
+watchdog_func &
+WATCHDOG_PID=$!
+
+# wait for exit statuses
+((NFAIL=0))
+for p in ${SSH_PIDS[*]}
+do
+    wait $p || ((NFAIL+=1))
+done
+wait $SW_PID || ((NFAIL+=1))
+
+# all done, let's terminate the watchdog
+kill $WATCHDOG_PID 2>/dev/null
+
+if ((NFAIL==0))
+then
+    echo "EXIT $(date)"
+else
+    echo "ABORT $(date)"
+fi
diff --git a/util/multi/bootscript.rcS b/util/dist/test/simple_bootscript.rcS
index 95736f4b7..7c9b75538 100644
--- a/util/multi/bootscript.rcS
+++ b/util/dist/test/simple_bootscript.rcS
@@ -40,33 +40,28 @@
 # Authors: Gabor Dozsa
 #
 #
-# This is an example boot script to use for muti gem5 runs. The important
-# task here is to extract the rank and size information from the kernel
-# boot args and use those to configure MAC/IP addresses and hostname.
-# Then we can kick off our (parallel) workload ...
+# This is an example boot script to use for dist-gem5 runs. The important
+# task here is to extract the rank and size information through the m5
+# initparam utility and use those to configure MAC/IP addresses and hostname.
 #
-# You are expected to costumize this scipt for your needs (e.g. change
+# You are expected to customize this scipt for your needs (e.g. change
 # the command at the end of the scipt to run your tests/workloads.
 
 source /root/.bashrc
 echo "bootscript.rcS is running"
 
-m='GEM5\_RANK=([0-9]+) GEM5\_SIZE=([0-9]+)'
-if [[ $(cat /proc/cmdline) =~ $m ]]
-then
-    MY_RANK=${BASH_REMATCH[1]}
-    MY_SIZE=${BASH_REMATCH[2]}
-else
-    echo "(E) GEM5_RANK/GEM5_SIZE was not defined in bootargs, exiting ..."
-    /sbin/m5 abort
-fi
+# Retrieve dist-gem5 rank and size parameters using the 'm5' utility
+MY_RANK=$(/sbin/m5 initparam dist-rank)
+[ $? = 0 ] || { echo "m5 initparam failed"; exit -1; }
+MY_SIZE=$(/sbin/m5 initparam dist-size)
+[ $? = 0 ] || { echo "m5 initparam failed"; exit -1; }
 
 /bin/hostname node${MY_RANK}
 
 # Keep MAC address assignment simple for now ...
-(($MY_RANK>97)) && { echo "(E) Rank must be less than 98"; /sbin/m5 abort; }
-((MY_ADDR=MY_RANK+2))
-if (($MY_ADDR<10))
+(($MY_RANK > 97)) && { echo "(E) Rank must be less than 98"; /sbin/m5 abort; }
+((MY_ADDR = MY_RANK + 2))
+if (($MY_ADDR < 10))
 then
     MY_ADDR_PADDED=0${MY_ADDR}
 else
@@ -78,45 +73,35 @@ fi
 
 /sbin/ifconfig -a
 
-# Prepare host lists for mpirun
-MY_MPI_HOSTS="192.168.0.2"
-for ((i=1; i<MY_SIZE; i++))
-do
-    MY_MPI_HOSTS+=",192.168.0.$((i+2))"
-done
+echo "Hello from $MY_RANK of $MY_SIZE"
 
-# Check that Ethernet links work, then take a checkpoint
-if  [ "$MY_RANK" == "0" ]
+# Now that our network interface is configured we can use the usual commands to
+# contact the other systems, e.g. let's try to ping a "neighbour" system
+if ((MY_RANK < MY_SIZE - 1))
 then
-    OLDIFS=$IFS
-    IFS=","
-    for i in $MY_MPI_HOSTS
-    do
-        ping -c 1  $i || { echo "ping $i failed, exiting ..."; exit -1; }
-        ssh $i hostname || { echo "ssh $i failed, exiting ..."; exit -1; }
-    done
-    IFS=$OLDIFS
-    /sbin/m5 checkpoint
+    ping -c 1 192.168.0.$((MY_ADDR + 1))
+else
+    ping -c 1 192.168.0.2
 fi
 
-# --------------------------------------------
-#  ------ Start your tests below ... ---------
-# --------------------------------------------
 
 if [ "$MY_RANK" == "0" ]
 then
-    echo "MPI test"
-    #mpirun -H 192.168.0.3,192.168.0.2 hostname
-    cd /benchmarks
-    mpirun -H $MY_MPI_HOSTS lulesh/lulesh2.0-mpi -s 5
+    # Trigger an immediate checkpoint at the next sync (by passing a non-zero
+    # delay param to m5 ckpt)
+    /sbin/m5 checkpoint 1
+    echo "A real multi node workload might start here ..."
+    # Trigger an immediate exit at the next sync (by passing a non-zero delay
+    # param to m5 exit)
+    /sbin/m5 exit 1
 else
     # This is to avoid other (rank!=0) gem5 processes exiting
     # before the test (started by rank 0) completes. When rank 0 completes the
-    # test it will exit and that will trigger a notification to all the peer 
-    # gem5 peocesses to stop the simulation.
+    # test it will exit and that will trigger a notification to all the peer
+    # gem5 processes to stop the simulation.
     echo "sleep forever..."
     while /bin/true
     do
-        sleep 5
+	sleep 5
     done
 fi
diff --git a/util/dist/test/test-2nodes-AArch64.sh b/util/dist/test/test-2nodes-AArch64.sh
new file mode 100644
index 000000000..ebdf07110
--- /dev/null
+++ b/util/dist/test/test-2nodes-AArch64.sh
@@ -0,0 +1,82 @@
+#! /bin/bash
+
+#
+# Copyright (c) 2015 ARM Limited
+# All rights reserved
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Gabor Dozsa
+#
+#
+# This is an example script to start a dist gem5 simulations using
+# two AArch64 systems. It is also uses the example
+# dist gem5 bootscript util/dist/test/simple_bootscript.rcS that will
+# run the linux ping command to check if we can see the peer system
+# connected via the simulated Ethernet link.
+
+GEM5_DIR=$(pwd)/$(dirname $0)/../../..
+
+IMG=$M5_PATH/disks/aarch64-ubuntu-trusty-headless.img
+VMLINUX=$M5_PATH/binaries/vmlinux.aarch64.20140821
+DTB=$M5_PATH/binaries/vexpress.aarch64.20140821.dtb
+
+FS_CONFIG=$GEM5_DIR/configs/example/fs.py
+SW_CONFIG=$GEM5_DIR/configs/example/sw.py
+GEM5_EXE=$GEM5_DIR/build/ARM/gem5.opt
+
+BOOT_SCRIPT=$GEM5_DIR/util/dist/test/simple_bootscript.rcS
+GEM5_DIST_SH=$GEM5_DIR/util/dist/gem5-dist.sh
+
+DEBUG_FLAGS="--debug-flags=DistEthernet"
+#CHKPT_RESTORE="-r1"
+
+NNODES=2
+
+$GEM5_DIST_SH -n $NNODES                                                     \
+              -x $GEM5_EXE                                                   \
+              -s $SW_CONFIG                                                  \
+              -f $FS_CONFIG                                                  \
+              --m5-args                                                      \
+                 $DEBUG_FLAGS                                                \
+              --fs-args                                                      \
+                  --cpu-type=atomic                                          \
+		  --num-cpus=1                                               \
+                  --machine-type=VExpress_EMM64                              \
+                  --disk-image=$IMG                                          \
+                  --kernel=$VMLINUX                                          \
+                  --dtb-filename=$DTB                                        \
+                  --script=$BOOT_SCRIPT                                      \
+              --cf-args                                                      \
+                  $CHKPT_RESTORE
+
diff --git a/util/multi/gem5-multi.sh b/util/multi/gem5-multi.sh
deleted file mode 100755
index 4b4937c90..000000000
--- a/util/multi/gem5-multi.sh
+++ /dev/null
@@ -1,275 +0,0 @@
-#! /bin/bash
-
-#
-# Copyright (c) 2015 ARM Limited
-# All rights reserved
-#
-# The license below extends only to copyright in the software and shall
-# not be construed as granting a license to any other intellectual
-# property including but not limited to intellectual property relating
-# to a hardware implementation of the functionality of the software
-# licensed hereunder.  You may use the software subject to the license
-# terms below provided that you ensure that this notice is replicated
-# unmodified and in its entirety in all distributions of the software,
-# modified or unmodified, in source code or in binary form.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met: redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer;
-# redistributions in binary form must reproduce the above copyright
-# notice, this list of conditions and the following disclaimer in the
-# documentation and/or other materials provided with the distribution;
-# neither the name of the copyright holders nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-#
-# Authors: Gabor Dozsa
-
-
-# This is a wrapper script to run a multi gem5 simulations.
-# See the usage_func() below for hints on how to use it. Also,
-# there are some examples in the util/multi directory (e.g.
-# see util/multi/test-2nodes-AArch64.sh)
-#
-#
-# Allocated hosts/cores are assumed to be listed in the LSB_MCPU_HOSTS
-# environment variable (which is what LSF does by default).
-# E.g. LSB_MCPU_HOSTS=\"hname1 2 hname2 4\" means we have altogether 6 slots
-# allocated to launch the gem5 processes, 2 of them are on host hname1
-# and 4 of them are on host hname2.
-# If LSB_MCPU_HOSTS environment variable is not defined then we launch all
-# processes on the localhost.
-#
-# Each gem5 process are passed in a unique rank ID [0..N-1] via the kernel
-# boot params. The total number of gem5 processes is also passed in.
-# These values can be used in the boot script to configure the MAC/IP
-# addresses - among other things (see util/multi/bootscript.rcS).
-#
-# Each gem5 process will create an m5out.$GEM5_RANK directory for
-# the usual output files. Furthermore, there will be a separate log file
-# for each ssh session (we use ssh to start gem5 processes) and one for
-# the server. These are called log.$GEM5_RANK and log.server.
-#
-
-
-# print help
-usage_func ()
-{
-    echo "Usage:$0 [-debug] [-n nnodes] [-s server] [-p port] gem5_exe gem5_args"
-    echo "     -debug   : debug mode (start gem5 in gdb)"
-    echo "     nnodes   : number of gem5 processes"
-    echo "     server   : message server executable"
-    echo "     port     : message server listen port"
-    echo "     gem5_exe : gem5 executable (full path required)"
-    echo "     gem5_args: usual gem5 arguments ( m5 options, config script options)"
-    echo "Note: if no LSF slots allocation is found all proceses are launched on the localhost."
-}
-
-
-# Process (optional) command line options
-
-while true
-do
-    case "x$1" in
-        x-n|x-nodes)
-            NNODES=$2
-            shift 2
-            ;;
-        x-s|x-server)
-            TCP_SERVER=$2
-            shift 2
-            ;;
-        x-p|x-port)
-            SERVER_PORT=$2
-            shift 2
-            ;;
-        x-debug)
-            GEM5_DEBUG="-debug"
-            shift 1
-            ;;
-        *)
-            break
-            ;;
-    esac
-done
-
-# The remaining command line args must be the usual gem5 command
-(($# < 2)) && { usage_func; exit -1; }
-GEM5_EXE=$1
-shift
-GEM5_ARGS="$*"
-
-# Default values to use (in case they are not defined as command line options)
-DEFAULT_TCP_SERVER=$(dirname $0)/../../util/multi/tcp_server
-DEFAULT_SERVER_PORT=2200
-
-[ -z "$TCP_SERVER" ]  && TCP_SERVER=$DEFAULT_TCP_SERVER
-[ -z "$SERVER_PORT" ] && SERVER_PORT=$DEFAULT_SERVER_PORT
-[ -z "$NNODES" ]      && NNODES=2
-
-
-#  Check if all the executables we need exist
-[ -x "$TCP_SERVER" ] || { echo "Executable ${TCP_SERVER} not found"; exit 1; }
-[ -x "$GEM5_EXE" ]   || { echo "Executable ${GEM5_EXE} not found"; exit 1; }
-
-
-declare -a SSH_PIDS
-declare -a HOSTS
-declare -a NCORES
-
-# Find out which cluster hosts/slots are allocated or
-# use localhost if there is no LSF allocation.
-# We assume that allocated slots are listed in the LSB_MCPU_HOSTS
-# environment variable in the form:
-# host1 nslots1 host2 nslots2 ...
-# (This is what LSF does by default.)
-NH=0
-[ "x$LSB_MCPU_HOSTS" != "x" ] || LSB_MCPU_HOSTS="localhost $NNODES"
-host=""
-for hc in $LSB_MCPU_HOSTS
-do
-    if [ "x$host" == "x" ]
-    then
-        host=$hc
-        HOSTS+=($hc)
-    else
-        NCORES+=($hc)
-        ((NH+=hc))
-        host=""
-    fi
-done
-((NNODES==NH)) || { echo "(E) Number of cluster slots ($NH) and gem5 instances ($N) differ"; exit -1; }
-#echo "hosts: ${HOSTS[@]}"
-#echo "hosts: ${NCORES[@]}"
-#echo ${#HOSTS[@]}
-
-
-# function to clean up and abort if something goes wrong
-abort_func ()
-{
-    echo
-    echo "KILLED $(date)"
-    # (try to) kill all gem5 processes on all hosts
-    bname=$(basename $GEM5_EXE)
-    killall -q $bname
-    for h in ${HOSTS[@]}
-    do
-        ssh $h killall -q $bname
-    done
-    sleep 3
-    # kill the message server and the watchdog
-    [ "x$SERVER_PID" != "x" ] && kill $SERVER_PID 2>/dev/null
-    [ "x$WATCHDOG_PID" != "x" ] && kill $WATCHDOG_PID 2>/dev/null
-    exit -1
-}
-
-
-# We need a watchdog to trigger full clean up if a gem5 process dies
-watchdog_func ()
-{
-    while true
-    do
-        sleep 30
-        ((NDEAD=0))
-        for p in ${SSH_PIDS[*]}
-        do
-            kill -0 $p 2>/dev/null || ((NDEAD+=1))
-        done
-        kill -0 $SERVER_PID || ((NDEAD+=1))
-        if ((NDEAD>0))
-        then
-            # we may be in the middle of an orderly termination,
-            # give it some time to complete before reporting abort
-            sleep 60
-            echo -n "(I) (some) gem5 process(es) exited"
-            abort_func
-        fi
-    done
-}
-
-# This function launches the gem5 processes. We use it only to allow launching
-# gem5 processes under gdb control (in the foreground) for debugging
-start_func ()
-{
-    local N=$1
-    local HOST=$2
-    local ENV_ARGS=$3
-    shift 3
-    if [ "x$GEM5_DEBUG" != "x" ]
-    then
-        gdb --args "$@"
-    else
-        ssh $HOST $ENV_ARGS "$@" &>log.$N & 
-    fi
-}
-
-
-# Trigger full clean up in case we are being killed by external signal
-trap 'abort_func' INT TERM
-
-# env args to be passed explicitly to gem5 processes started via ssh
-ENV_ARGS="LD_LIBRARY_PATH=$LD_LIBRARY_PATH M5_PATH=$M5_PATH"
-
-# launch the mesage server and check if it has started okay
-$TCP_SERVER $GEM5_DEBUG $NNODES $SERVER_PORT &>log.server &
-SERVER_PID=$!
-sleep 2
-kill -0 $SERVER_PID || { echo "Failed to start message server"; exit -1; }
-
-# Now launch all the gem5 processes with ssh.
-echo "START $(date)"
-n=0
-for ((i=0; i < ${#HOSTS[@]}; i++))
-do
-    h=${HOSTS[$i]}
-    for ((j=0; j < ${NCORES[i]}; j++))
-    do
-        echo "starting gem5 on $h ..."
-        start_func $n $h "$ENV_ARGS" $GEM5_EXE -d $(pwd)/m5out.$n $GEM5_ARGS \
-        --multi                                                              \
-        --multi-rank=$n                                                      \
-        --multi-server-name=${HOSTS[0]}                                      \
-        --multi-server-port=$SERVER_PORT                                     \
-        --testsys-toplevel-LinuxArmSystem.boot_osflags="\"GEM5_RANK=$n GEM5_SIZE=$NNODES\""
-        SSH_PIDS[$n]=$!
-        ((n+=1))
-    done
-done
-
-[ "x$GEM5_DEBUG" == "x" ] || {  kill $SERVER_PID; echo "DEBUG exit"; exit -1; }
-
-# start watchdog to trigger complete abort (after a grace period) if any
-# gem5 process dies
-watchdog_func &
-WATCHDOG_PID=$!
-
-# wait for exit statuses
-((NFAIL=0))
-for p in ${SSH_PIDS[*]}
-do
-    wait $p || ((NFAIL+=1))
-done
-wait $SERVER_PID || ((NFAIL+=1))
-
-# all done, let's terminate the watchdog
-kill $WATCHDOG_PID 2>/dev/null
-
-if ((NFAIL==0))
-then
-    echo "EXIT $(date)"
-else
-    echo "ABORT $(date)"
-fi