# Copyright (c) 2021 The Regents of the University of California.
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"""
Script to run SPEC CPU2006 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 GiB 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-cpu2006-benchmarks.py \
    --image <full_path_to_the_spec-2006_disk_image> \
    --partition <root_partition_to_mount> \
    --benchmark <benchmark_name> \
    --size <simulation_size>
```

"""

import argparse
import json
import os
import time

import m5
from m5.objects import Root
from m5.stats.gem5stats import get_simstat
from m5.util import (
    fatal,
    warn,
)

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

# 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 CPU2006.
# Note that 400.perlbench, 447.dealII, 450.soplex and 483.xalancbmk
# have build errors, and, therefore cannot be executed. More information is
# available at: https://www.gem5.org/documentation/benchmark_status/gem5-20

benchmark_choices = [
    "400.perlbench",
    "401.bzip2",
    "403.gcc",
    "410.bwaves",
    "416.gamess",
    "429.mcf",
    "433.milc",
    "435.gromacs",
    "436.cactusADM",
    "437.leslie3d",
    "444.namd",
    "445.gobmk",
    "447.dealII",
    "450.soplex",
    "453.povray",
    "454.calculix",
    "456.hmmer",
    "458.sjeng",
    "459.GemsFDTD",
    "462.libquantum",
    "464.h264ref",
    "465.tonto",
    "470.lbm",
    "471.omnetpp",
    "473.astar",
    "481.wrf",
    "482.sphinx3",
    "483.xalancbmk",
    "998.specrand",
    "999.specrand",
]

# Following are the input size.

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

parser = argparse.ArgumentParser(
    description="An example configuration script to run the \
        SPEC CPU2006 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-2006 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="32KiB",
    l1d_assoc=8,
    l1i_size="32KiB",
    l1i_assoc=8,
    l2_size="256KiB",
    l2_assoc=16,
    num_l2_banks=2,
)
# Memory: Dual Channel DDR4 2400 DRAM device.
# The X86 board only supports 3 GiB of main memory.

memory = DualChannelDDR4_2400(size="3GiB")

# 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 CPU2006 benchmarks output placed in /home/gem5/spec2006/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 CPU2006 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/spec2006/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}"

board.set_kernel_disk_workload(
    # The x86 linux kernel will be automatically downloaded to the
    # `~/.cache/gem5` directory if not already present.
    # SPEC CPU2006 benchamarks were tested with kernel version 4.19.83 and
    # 5.4.49
    kernel=Resource("x86-linux-kernel-4.19.83"),
    # The location of the x86 SPEC CPU 2017 image
    disk_image=DiskImageResource(args.image, 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()

# Simulation is over at this point. We acknowledge that all the simulation
# events were successful.
print("All simulation events were successful.")
# We print the final simulation statistics.

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)
)