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"""
Script to run PARSEC benchmarks with gem5.
The script expects a benchmark program name and the simulation
size. The system is fixed with 2 CPU cores, MESI Two Level system
cache and 3 GB DDR4 memory. It uses the x86 board.

This script will count the total number of instructions executed
in the ROI. It also tracks how much wallclock and simulated time.

Usage:
------

```
scons build/X86/gem5.opt
./build/X86/gem5.opt \
    configs/example/gem5_library/x86-parsec-benchmarks.py \
    --benchmark <benchmark_name> \
    --size <simulation_size>
```
"""
import argparse
import time

import m5
from m5.objects import Root

from gem5.utils.requires import requires
from gem5.components.boards.x86_board import X86Board
from gem5.components.memory import DualChannelDDR4_2400
from gem5.components.processors.simple_switchable_processor import (
    SimpleSwitchableProcessor,
)
from gem5.components.processors.cpu_types import CPUTypes
from gem5.isas import ISA
from gem5.coherence_protocol import CoherenceProtocol
from gem5.resources.resource import Resource
from gem5.simulate.simulator import Simulator
from gem5.simulate.exit_event import ExitEvent

# We check for the required gem5 build.

requires(
    isa_required=ISA.X86,
    coherence_protocol_required=CoherenceProtocol.MESI_TWO_LEVEL,
    kvm_required=True,
)

# Following are the list of benchmark programs for parsec.

benchmark_choices = [
    "blackscholes",
    "bodytrack",
    "canneal",
    "dedup",
    "facesim",
    "ferret",
    "fluidanimate",
    "freqmine",
    "raytrace",
    "streamcluster",
    "swaptions",
    "vips",
    "x264",
]

# Following are the input size.

size_choices = ["simsmall", "simmedium", "simlarge"]

parser = argparse.ArgumentParser(
    description="An example configuration script to run the npb benchmarks."
)

# The arguments accepted are the benchmark name and the simulation size.

parser.add_argument(
    "--benchmark",
    type=str,
    required=True,
    help="Input the benchmark program to execute.",
    choices=benchmark_choices,
)

parser.add_argument(
    "--size",
    type=str,
    required=True,
    help="Simulation size the benchmark program.",
    choices=size_choices,
)
args = parser.parse_args()

# Setting up all the fixed system parameters here
# Caches: MESI Two Level Cache Hierarchy

from gem5.components.cachehierarchies.ruby.mesi_two_level_cache_hierarchy import (
    MESITwoLevelCacheHierarchy,
)

cache_hierarchy = MESITwoLevelCacheHierarchy(
    l1d_size="32kB",
    l1d_assoc=8,
    l1i_size="32kB",
    l1i_assoc=8,
    l2_size="256kB",
    l2_assoc=16,
    num_l2_banks=2,
)

# Memory: Dual Channel DDR4 2400 DRAM device.
# The X86 board only supports 3 GB of main memory.

memory = DualChannelDDR4_2400(size="3GB")

# Here we setup the processor. This is a special switchable processor in which
# a starting core type and a switch core type must be specified. Once a
# configuration is instantiated a user may call `processor.switch()` to switch
# from the starting core types to the switch core types. In this simulation
# we start with KVM cores to simulate the OS boot, then switch to the Timing
# cores for the command we wish to run after boot.

processor = SimpleSwitchableProcessor(
    starting_core_type=CPUTypes.KVM,
    switch_core_type=CPUTypes.TIMING,
    isa=ISA.X86,
    num_cores=2,
)

# Here we setup the board. The X86Board allows for Full-System X86 simulations

board = X86Board(
    clk_freq="3GHz",
    processor=processor,
    memory=memory,
    cache_hierarchy=cache_hierarchy,
)

# Here we set the FS workload, i.e., parsec benchmark
# After simulation has ended you may inspect
# `m5out/system.pc.com_1.device` to the stdout, if any.

# After the system boots, we execute the benchmark program and wait till the
# ROI `workbegin` annotation is reached (m5_work_begin()). We start collecting
# the number of committed instructions till ROI ends (marked by `workend`).
# We then finish executing the rest of the benchmark.

# Also, we sleep the system for some time so that the output is printed
# properly.


command = (
    "cd /home/gem5/parsec-benchmark;".format(args.benchmark)
    + "source env.sh;"
    + "parsecmgmt -a run -p {} -c gcc-hooks -i {} \
        -n {};".format(
        args.benchmark, args.size, "2"
    )
    + "sleep 5;"
    + "m5 exit;"
)
board.set_kernel_disk_workload(
    # The x86 linux kernel will be automatically downloaded to the
    # `~/.cache/gem5` directory if not already present.
    # PARSEC benchamarks were tested with kernel version 4.19.83
    kernel=Resource("x86-linux-kernel-4.19.83"),
    # The x86-parsec image will be automatically downloaded to the
    # `~/.cache/gem5` directory if not already present.
    disk_image=Resource("x86-parsec"),
    readfile_contents=command,
)

# functions to handle different exit events during the simuation
def handle_workbegin():
    print("Done booting Linux")
    print("Resetting stats at the start of ROI!")
    m5.stats.reset()
    processor.switch()
    yield False


def handle_workend():
    print("Dump stats at the end of the ROI!")
    m5.stats.dump()
    yield True


simulator = Simulator(
    board=board,
    on_exit_event={
        ExitEvent.WORKBEGIN: handle_workbegin(),
        ExitEvent.WORKEND: handle_workend(),
    },
)

# We maintain the wall clock time.

globalStart = time.time()

print("Running the simulation")
print("Using KVM cpu")

m5.stats.reset()

# We start the simulation
simulator.run()

print("All simulation events were successful.")

# We print the final simulation statistics.

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

print("Simulated time in ROI: " + ((str(simulator.get_roi_ticks()[0]))))
print(
    "Ran a total of", simulator.get_current_tick() / 1e12, "simulated seconds"
)
print(
    "Total wallclock time: %.2fs, %.2f min"
    % (time.time() - globalStart, (time.time() - globalStart) / 60)
)