Facebook AI Performance Evaluation Platform

Facebook AI Performance Evaluation Platform is a framework and backend agnostic benchmarking platform to compare machine learning inferencing runtime metrics on a set of models and a variety of backends. It also provides a means to check performance regressions on each commit.

Currently two performance metrics are collected:

• delay : the delay of running the entire network and/or the delay of running each individual operator.
• error : the error between the values of the outputs running a model and the golden outputs.

Framework and backend agnostic benchmarking platforms

Machine learning is a rapidly evolving area with many moving parts: new and existing framework enhancements, new hardware solutions, new software backends, and new models. With so many moving parts, it is very difficult to quickly evaluate the performance of a machine learning model. However, such evaluation is vastly important in guiding resource allocation in:

• the development of the frameworks
• the optimization of the software backends
• the selection of the hardware solutions
• the iteration of the machine learning models

This project tries to achieve the following two goals:

• When a new model is added to be benchmarked, get the runtime performance of this model on all existing backends easily.
• When a new backend is added to be benchmarked, get the runtime performance of all existing models on this backend easily.

The flow of benchmarking is illustrated in the following figure:

The flow is composed of three parts:

• A centralized model/benchmark specification
  • A fair input to the comparison
• A centralized benchmark driver with distributed benchmark execution
  • The same code base for all backends to reduce variation
  • Distributed execution due to the unique build/run environment for each backend
• A centralized data consumption
  • One stop to compare the performance

The currently supported frameworks are: Caffe2

The currently supported model formats are: Caffe2

The currently supported backends: CPU, GPU, DSP, Android, linux based systems

The currently supported libraries: Eigen, MKL, NNPACK, OpenGL, CUDA

Performance regression detection

The benchmark platform also provides a means to compare performance between commits and detect regressions. It uses an A/B testing methodology that compares the runtime difference between a newer commit (treatment) and an older commit (control). What matters is the relative performance difference between the commits, as the backend platform's condition may be different at different times. Running the same tests on two different commit points at the same time removes most of the variations of the backend. This method has shown to improve the precision of detecting performance regressions.

Directory structure

The benchmarking codebase resides in benchmarking directory. Inside, the frameworks directory contains all supported ML frameworks. Add a new framework by creating a new directory, deriving from framework_base.py and implementing all its methods. The platforms directory contains all supported ML backend platforms. Add a new backend by creating a new directory, deriving from platform_base.py and implementing all its methods.

The model specifications resides in specifications directory. Inside, the models directory contains all model and benchmarking specifications organized in model format. The benchmarks directory contains a sequence of benchmarks organized in model format. The frameworks directory contains custom build scripts for each framework.

Model/Benchmark specification

The models and benchmarks are specified in json format. It is best to use the example in /specifications/models/caffe2/squeezenet/squeezenet.json as an example to understand what data is specified.

A few key items in the specifications

• The models are hosted in third party storage. The download links and their MD5 hashes are specified. The benchmarking tool automatically downloads the model if not found in the local model cache. The MD5 hash of the cached model is computed and compared with the specified one. If they do not match, the model is downloaded again and the MD5 hash is recomputed. This way, if the model is changed, only need to update the specification and the new model is downloaded automatically.
• In the inputs field of tests, one may specify multiple shapes. This is a short hand to indicate that we benchmark the tests of all shapes in sequence.
• In some field, such as identifier, you may find some string like {ID}. This is a placeholder to be replaced by the benchmarking tool to differentiate multiple test runs specified in one test specification, as in the above item.

Run benchmark

To run the benchmark, you need to run run_bench.py, given a model meta data or a benchmark meta data. An example of the command is:

run_bench.py -b caffe2-benchmarking/specifications/models/caffe2/shufflenet/shufflenet.json

When you run the command for the first time, you are asked several questions. The answers to those questions, together with other sensible defaults, are saved in a config file: ~/.aibench/git/config.txt. You can edit the file to update your default arguments.

The arguments to the driver are as follows. It also takes arguments specified in the following sections and pass them to those scripts.

usage: run_bench.py [-h] [--reset_options]

Perform one benchmark run

optional arguments:
  -h, --help       show this help message and exit
  --reset_options  Reset all the options that is saved by default.

run_bench.py can be the single point of entry for both interactive and regression benchmark runs.

Stand alone benchmark run

The harness.py is the entry point for one benchmark run. It collects the runtime for an entire net and/or individual operator, and saves the data locally or pushes to a remote server. The usage of the script is as follows:

usage: harness.py [-h] [--android_dir ANDROID_DIR] [--backend BACKEND] -b
                  BENCHMARK_FILE [-d DEVICES]
                  [--excluded_devices EXCLUDED_DEVICES] --framework
                  {caffe2,generic,oculus} --info INFO
                  [--local_reporter LOCAL_REPORTER]
                  [--simple_local_reporter SIMPLE_LOCAL_REPORTER]
                  --model_cache MODEL_CACHE [--device DEVICE] -p PLATFORM
                  [--platform_sig PLATFORM_SIG] [--wipe_cache WIPE_CACHE]
                  [--program PROGRAM] [--reboot]
                  [--regressed_types REGRESSED_TYPES]
                  [--remote_reporter REMOTE_REPORTER]
                  [--remote_access_token REMOTE_ACCESS_TOKEN]
                  [--root_model_dir ROOT_MODEL_DIR]
                  [--run_type {benchmark,verify,regress}] [--screen_reporter]
                  [--simple_screen_reporter] [--set_freq SET_FREQ]
                  [--shared_libs SHARED_LIBS] [--timeout TIMEOUT]
                  [--user_identifier USER_IDENTIFIER]

Perform one benchmark run

optional arguments:
  -h, --help            show this help message and exit
  --android_dir ANDROID_DIR
                        The directory in the android device all files are
                        pushed to.
  --backend BACKEND     Specify the backend the test runs on.
  -b BENCHMARK_FILE, --benchmark_file BENCHMARK_FILE
                        Specify the json file for the benchmark or a number of
                        benchmarks
  -d DEVICES, --devices DEVICES
                        Specify the devices to run the benchmark, in a comma
                        separated list. The value is the device or device_hash
                        field of the meta info.
  --excluded_devices EXCLUDED_DEVICES
                        Specify the devices that skip the benchmark, in a
                        comma separated list. The value is the device or
                        device_hash field of the meta info.
  --framework {caffe2,generic,oculus}
                        Specify the framework to benchmark on.
  --info INFO           The json serialized options describing the control and
                        treatment.
  --local_reporter LOCAL_REPORTER
                        Save the result to a directory specified by this
                        argument.
  --simple_local_reporter SIMPLE_LOCAL_REPORTER
                        Same as local reporter, but the directory hierarchy is
                        reduced.
  --model_cache MODEL_CACHE
                        The local directory containing the cached models. It
                        should not be part of a git directory.
  --device DEVICE       The single device to run this benchmark on
  -p PLATFORM, --platform PLATFORM
                        Specify the platform to benchmark on. Use this flag if
                        the framework needs special compilation scripts. The
                        scripts are called build.sh saved in
                        specifications/frameworks/<framework>/<platform>
                        directory
  --platform_sig PLATFORM_SIG
                        Specify the platform signature
  --wipe_cache WIPE_CACHE
                        Specify whether to evict cache or not before running
  --program PROGRAM     The program to run on the platform.
  --reboot              Tries to reboot the devices before launching
                        benchmarks for one commit.
  --regressed_types REGRESSED_TYPES
                        A json string that encodes the types of the regressed
                        tests.
  --remote_reporter REMOTE_REPORTER
                        Save the result to a remote server. The style is
                        <domain_name>/<endpoint>|<category>
  --remote_access_token REMOTE_ACCESS_TOKEN
                        The access token to access the remote server
  --root_model_dir ROOT_MODEL_DIR
                        The root model directory if the meta data of the model
                        uses relative directory, i.e. the location field
                        starts with //
  --run_type {benchmark,verify,regress}
                        The type of the current run. The allowed values are:
                        benchmark, the normal benchmark run.verify, the
                        benchmark is re-run to confirm a suspicious
                        regression.regress, the regression is confirmed.
  --screen_reporter     Display the summary of the benchmark result on screen.
  --simple_screen_reporter
                        Display the result on screen with no post processing.
  --set_freq SET_FREQ   On rooted android phones, set the frequency of the
                        cores. The supported values are: max: set all cores to
                        the maximum frquency. min: set all cores to the
                        minimum frequency. mid: set all cores to the median
                        frequency.
  --shared_libs SHARED_LIBS
                        Pass the shared libs that the framework depends on, in
                        a comma separated list.
  --timeout TIMEOUT     Specify a timeout running the test on the platforms.
                        The timeout value needs to be large enough so that the
                        low end devices can safely finish the execution in
                        normal conditions. Note, in A/B testing mode, the test
                        runs twice.
  --user_identifier USER_IDENTIFIER
                        User can specify an identifier and that will be passed
                        to the output so that the result can be easily
                        identified.

Continuous benchmark run

The repo_driver.py is the entry point to run the benchmark continuously. It repeatedly pulls the framework from github, builds the framework, and launches the harness.py with the built benchmarking binaries

The accepted arguments are as follows:

usage: repo_driver.py [-h] [--ab_testing] [--base_commit BASE_COMMIT]
                      [--branch BRANCH] [--commit COMMIT]
                      [--commit_file COMMIT_FILE] --exec_dir EXEC_DIR
                      --framework {caffe2,oculus,generic}
                      [--frameworks_dir FRAMEWORKS_DIR] [--interval INTERVAL]
                      --platforms PLATFORMS [--regression]
                      [--remote_repository REMOTE_REPOSITORY]
                      [--repo {git,hg}] --repo_dir REPO_DIR [--same_host]
                      [--status_file STATUS_FILE] [--step STEP]

Perform one benchmark run

optional arguments:
  -h, --help            show this help message and exit
  --ab_testing          Enable A/B testing in benchmark.
  --base_commit BASE_COMMIT
                        In A/B testing, this is the control commit that is
                        used to compare against. If not specified, the default
                        is the first commit in the week in UTC timezone. Even
                        if specified, the control is the later of the
                        specified commit and the commit at the start of the
                        week.
  --branch BRANCH       The remote repository branch. Defaults to master
  --commit COMMIT       The commit this benchmark runs on. It can be a branch.
                        Defaults to master. If it is a commit hash, and
                        program runs on continuous mode, it is the starting
                        commit hash the regression runs on. The regression
                        runs on all commits starting from the specified
                        commit.
  --commit_file COMMIT_FILE
                        The file saves the last commit hash that the
                        regression has finished. If this argument is specified
                        and is valid, the --commit has no use.
  --exec_dir EXEC_DIR   The executable is saved in the specified directory. If
                        an executable is found for a commit, no re-compilation
                        is performed. Instead, the previous compiled
                        executable is reused.
  --framework {caffe2,oculus,generic}
                        Specify the framework to benchmark on.
  --frameworks_dir FRAMEWORKS_DIR
                        Required. The root directory that all frameworks
                        resides. Usually it is the specifications/frameworks
                        directory.
  --interval INTERVAL   The minimum time interval in seconds between two
                        benchmark runs.
  --platforms PLATFORMS
                        Specify the platforms to benchmark on, in comma
                        separated list.Use this flag if the framework needs
                        special compilation scripts. The scripts are called
                        build.sh saved in
                        specifications/frameworks/<framework>/<platforms>
                        directory
  --regression          Indicate whether this run detects regression.
  --remote_repository REMOTE_REPOSITORY
                        The remote repository. Defaults to origin
  --repo {git,hg}       Specify the source control repo of the framework.
  --repo_dir REPO_DIR   Required. The base framework repo directory used for
                        benchmark.
  --same_host           Specify whether the build and benchmark run are on the
                        same host. If so, the build cannot be done in parallel
                        with the benchmark run.
  --status_file STATUS_FILE
                        A file to inform the driver stops running when the
                        content of the file is 0.
  --step STEP           Specify the number of commits we want to run the
                        benchmark once under continuous mode.

The repo_driver.py can also take the arguments that are recognized by harness.py. It just passes those arguments over.