# Copyright (c) 2021 The Regents of the University of California.
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#
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"""
Script to run SPEC CPU2017 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-spec-cpu2017-benchmarks.py \
    --image <full_path_to_the_spec-2017_disk_image> \
    --partition <root_partition_to_mount> \
    --benchmark <benchmark_name> \
    --size <simulation_size>
```
"""

import argparse
import time
import os
import json

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, CustomDiskImageResource
from gem5.simulate.simulator import Simulator
from gem5.simulate.exit_event import ExitEvent

from m5.stats.gem5stats import get_simstat
from m5.util import warn
from m5.util import fatal

# 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 SPEC CPU2017.
# More information is available at:
# https://www.gem5.org/documentation/benchmark_status/gem5-20

benchmark_choices = [
    "500.perlbench_r",
    "502.gcc_r",
    "503.bwaves_r",
    "505.mcf_r",
    "507.cactusBSSN_r",
    "508.namd_r",
    "510.parest_r",
    "511.povray_r",
    "519.lbm_r",
    "520.omnetpp_r",
    "521.wrf_r",
    "523.xalancbmk_r",
    "525.x264_r",
    "527.cam4_r",
    "531.deepsjeng_r",
    "538.imagick_r",
    "541.leela_r",
    "544.nab_r",
    "548.exchange2_r",
    "549.fotonik3d_r",
    "554.roms_r",
    "557.xz_r",
    "600.perlbench_s",
    "602.gcc_s",
    "603.bwaves_s",
    "605.mcf_s",
    "607.cactusBSSN_s",
    "608.namd_s",
    "610.parest_s",
    "611.povray_s",
    "619.lbm_s",
    "620.omnetpp_s",
    "621.wrf_s",
    "623.xalancbmk_s",
    "625.x264_s",
    "627.cam4_s",
    "631.deepsjeng_s",
    "638.imagick_s",
    "641.leela_s",
    "644.nab_s",
    "648.exchange2_s",
    "649.fotonik3d_s",
    "654.roms_s",
    "996.specrand_fs",
    "997.specrand_fr",
    "998.specrand_is",
    "999.specrand_ir",
]

# Following are the input size.

size_choices = ["test", "train", "ref"]

parser = argparse.ArgumentParser(
    description="An example configuration script to run the \
        SPEC CPU2017 benchmarks."
)

# The arguments accepted are: a. disk-image name, b. benchmark name, c.
# simulation size, and, d. root partition.

# root partition is set to 1 by default.

parser.add_argument(
    "--image",
    type=str,
    required=True,
    help="Input the full path to the built spec-2017 disk-image.",
)

parser.add_argument(
    "--partition",
    type=str,
    required=False,
    default=None,
    help='Input the root partition of the SPEC disk-image. If the disk is \
    not partitioned, then pass "".',
)

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="Sumulation size the benchmark program.",
    choices=size_choices,
)

args = parser.parse_args()

# We expect the user to input the full path of the disk-image.
if args.image[0] != "/":
    # We need to get the absolute path to this file. We assume that the file is
    # present on the current working directory.
    args.image = os.path.abspath(args.image)

if not os.path.exists(args.image):
    warn("Disk image not found!")
    print("Instructions on building the disk image can be found at: ")
    print(
        "https://gem5art.readthedocs.io/en/latest/tutorials/spec-tutorial.html"
    )
    fatal(f"The disk-image is not found at {args.image}")

# 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,
)

# SPEC CPU2017 benchmarks output placed in /home/gem5/spec2017/results
# directory on the disk-image. The following folder is created in the
# m5.options.outdir and the output from the disk-image folder is copied to
# this folder.

output_dir = "speclogs_" + "".join(x.strip() for x in time.asctime().split())
output_dir = output_dir.replace(":", "")

# We create this folder if it is absent.
try:
    os.makedirs(os.path.join(m5.options.outdir, output_dir))
except FileExistsError:
    warn("output directory already exists!")

# Here we set the FS workload, i.e., SPEC CPU2017 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
# `m5_exit instruction encountered` is encountered. We start collecting
# the number of committed instructions till ROI ends (marked by another
# `m5_exit instruction encountered`). We then start copying the output logs,
# present in the /home/gem5/spec2017/results directory to the `output_dir`.

# The runscript.sh file places `m5 exit` before and after the following command
# Therefore, we only pass this command without m5 exit.

command = f"{args.benchmark} {args.size} {output_dir}"

# For enabling CustomResource, we pass an additional parameter to mount the
# correct partition.

board.set_kernel_disk_workload(
    # The x86 linux kernel will be automatically downloaded to the
    # `~/.cache/gem5` directory if not already present.
    # SPEC CPU2017 benchamarks were tested with kernel version 4.19.83
    kernel=Resource("x86-linux-kernel-4.19.83"),
    # The location of the x86 SPEC CPU 2017 image
    disk_image=CustomDiskImageResource(
        args.image, disk_root_partition=args.partition
    ),
    readfile_contents=command,
)


def handle_exit():
    print("Done bootling Linux")
    print("Resetting stats at the start of ROI!")
    m5.stats.reset()
    processor.switch()
    yield False  # E.g., continue the simulation.
    print("Dump stats at the end of the ROI!")
    m5.stats.dump()
    yield True  # Stop the simulation. We're done.


simulator = Simulator(
    board=board,
    on_exit_event={
        ExitEvent.EXIT: handle_exit(),
    },
)

# 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()

# We print the final simulation statistics.

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

roi_begin_ticks = simulator.get_tick_stopwatch()[0][1]
roi_end_ticks = simulator.get_tick_stopwatch()[1][1]

print("roi simulated ticks: " + str(roi_end_ticks - roi_begin_ticks))

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)
)