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""" Script to run PARSEC benchmarks with gem5.
    The script expects kernel, diskimage, cpu (kvm or timing),
    benchmark, benchmark size, and number of cpu cores as arguments.
    This script is best used if your disk-image has workloads tha have
    ROI annotations compliant with m5 utility. You can use the script in
    ../disk-images/parsec/ with the parsec-benchmark repo at
    https://github.com/darchr/parsec-benchmark.git to create a working
    disk-image for this script.
"""
import errno
import os
import sys
import time
import m5
import m5.ticks
from m5.objects import *

sys.path.append('gem5/configs/common/') # For the next line...
import SimpleOpts

from system import *

def writeBenchScript(dir, bench, size):
    """
    This method creates a script in dir which will be eventually
    passed to the simulated system (to run a specific benchmark
    at bootup).
    """
    file_name = '{}/run_{}'.format(dir, bench)
    bench_file = open(file_name, 'w+')
    bench_file.write('cd /home/gem5/parsec-benchmark\n')
    bench_file.write('source env.sh\n')
    bench_file.write('parsecmgmt -a run -p \
            {} -c gcc-hooks -i {}\n'.format(bench, size))

    # sleeping for sometime makes sure
    # that the benchmark's output has been
    # printed to the console
    bench_file.write('sleep 5 \n')
    bench_file.write('m5 exit \n')
    bench_file.close()
    return file_name

if __name__ == "__m5_main__":
    (opts, args) = SimpleOpts.parse_args()
    kernel, disk, cpu, benchmark, size, num_cpus = args

    if not cpu in ['kvm', 'timing']:
        m5.fatal("cpu not supported")

    # create the system we are going to simulate
    system = MySystem(kernel, disk, int(num_cpus), opts, no_kvm=False)

    # Exit from guest on workbegin/workend
    system.exit_on_work_items = True

    # Create and pass a script to the simulated system to run the reuired
    # benchmark
    system.readfile = writeBenchScript(m5.options.outdir, benchmark, size)

    # set up the root SimObject and start the simulation
    root = Root(full_system = True, system = system)

    if system.getHostParallel():
        # Required for running kvm on multiple host cores.
        # Uses gem5's parallel event queue feature
        # Note: The simulator is quite picky about this number!
        root.sim_quantum = int(1e9) # 1 ms

    #needed for long running jobs
    m5.disableAllListeners()

    # instantiate all of the objects we've created above
    m5.instantiate()

    globalStart = time.time()

    print("Running the simulation")
    print("Using cpu: {}".format(cpu))

    start_tick = m5.curTick()
    end_tick = m5.curTick()
    start_insts = system.totalInsts()
    end_insts = system.totalInsts()
    m5.stats.reset()

    exit_event = m5.simulate()

    if exit_event.getCause() == "workbegin":
        # Reached the start of ROI
        # start of ROI is marked by an
        # m5_work_begin() call
        print("Resetting stats at the start of ROI!")
        m5.stats.reset()
        start_tick = m5.curTick()
        start_insts = system.totalInsts()
        # switching to timing cpu if argument cpu == timing
        if cpu == 'timing':
            system.switchCpus(system.cpu, system.timingCpu)
    else:
        print("Unexpected termination of simulation!")
        print()
        m5.stats.dump()
        end_tick = m5.curTick()
        end_insts = system.totalInsts()
        m5.stats.reset()
        print("Performance statistics:")

        print("Simulated time: %.2fs" % ((end_tick-start_tick)/1e12))
        print("Instructions executed: %d" % ((end_insts-start_insts)))
        print("Ran a total of", m5.curTick()/1e12, "simulated seconds")
        print("Total wallclock time: %.2fs, %.2f min" % \
                    (time.time()-globalStart, (time.time()-globalStart)/60))
        exit()

    # Simulate the ROI
    exit_event = m5.simulate()

    # Reached the end of ROI
    # Finish executing the benchmark with kvm cpu
    if exit_event.getCause() == "workend":
        # Reached the end of ROI
        # end of ROI is marked by an
        # m5_work_end() call
        print("Dump stats at the end of the ROI!")
        m5.stats.dump()
        end_tick = m5.curTick()
        end_insts = system.totalInsts()
        m5.stats.reset()
        # switching to timing cpu if argument cpu == timing
        if cpu == 'timing':
            system.switchCpus(system.timingCpu, system.cpu)
    else:
        print("Unexpected termination of simulation!")
        print()
        m5.stats.dump()
        end_tick = m5.curTick()
        end_insts = system.totalInsts()
        m5.stats.reset()
        print("Performance statistics:")

        print("Simulated time: %.2fs" % ((end_tick-start_tick)/1e12))
        print("Instructions executed: %d" % ((end_insts-start_insts)))
        print("Ran a total of", m5.curTick()/1e12, "simulated seconds")
        print("Total wallclock time: %.2fs, %.2f min" % \
                    (time.time()-globalStart, (time.time()-globalStart)/60))
        exit()

    # Simulate the remaning part of the benchmark
    exit_event = m5.simulate()

    print("Done with the simulation")
    print()
    print("Performance statistics:")

    print("Simulated time in ROI: %.2fs" % ((end_tick-start_tick)/1e12))
    print("Instructions executed in ROI: %d" % ((end_insts-start_insts)))
    print("Ran a total of", m5.curTick()/1e12, "simulated seconds")
    print("Total wallclock time: %.2fs, %.2f min" % \
                (time.time()-globalStart, (time.time()-globalStart)/60))