WIP staging repo - https://github.com/sandeep-krishnamurthy/dl-operator-benchmark
Link to dev list discussion
<TODO>
Feature Shepherd
Lin Yuan (https://github.com/apeforest)
Problem Statement
A deep learning framework like MXNet supports 100s of operators (~250). Benchmarking and profiling a standard neural network and use-case, like ResNet-50 based image classification, is not fully sufficient and does not guarantee to maintain the health and performance of all the supported operators under different settings (Hardware, Accelerator, Data etc...). We need to have an easy to use library/framework to benchmark and profile each operator individually. Having an operator level benchmarks will help us in - fine grained understanding of performance of operators under different settings (Hardware, Accelerator, Data etc...), automated CI/CD performance tests, plan performance optimization and more. In this document, we present a library for MXNet operator benchmark and profiling.
Motivation
A deep learning framework like MXNet supports 100s of operators (~250). Some operators are used as a layers in the neural network (ex: Conv2D), some operators work in combination to form a layer in the neural network (ex: dot, sum => Dense), and many more just used independently outside a neural network (ex: tensor creation/shape change/indexing, logical operators) mostly for data processing and tensor manipulation.
An operator is highly heterogeneous w.r.t supported precision (fp32, fp64, Int64 etc.), accelerators (mkldnn, cuda, cudnn, mxnet native only), different behaviors based on data (ex: broadcast sum behavior on a large square (1024, 1024) tensor is different than on a skewed tensor (10, 10000) and more). Below, we see few areas why we believe operator benchmarks are useful:
- Users use a lot more operators that are not part of a standard network like ResNet. Example: Tensor manipulation operators like mean, max, topk, argmax, sort etc.
- A standard Network Architecture like ResNet-50 is made up of many operators Ex: Convolution2D, Softmax, Dense, Pooling etc... Observing only the end to end performance can hide individual operator regressions for long time.
- We need to know on different hardware infrastructure (Ex: CPU with MKLDNN, GPU with NVIDIA CUDA and cuDNN) how different operators performs. With these details, we can plan the optimization work at operator level, which could exponentially boost up end to end performance.
- Operator behavior varies based on different data load:
- For example, MXNet's reduction operations works seamlessly with balanced tensor like (1024, 1024), however, performance behavior changes when the input tensor is skewed (1024, 10). Similar observations can be made when comparing Int32 v/s Int64 indexing of Tensor.
- See this issue - #14725 which talks about performance regression in FC layer backward pass with CUDA 10 based on input tensor shape - https://github.com/apache/incubator-mxnet/issues/14725#issuecomment-486016229
- You want to have nightly performance tests across all operators in a deep learning framework to catch regressions early.
- We can integrate this framework with a CI/CD system to run per operator performance tests for PRs. Ex: When a PR modifies the kernel of TransposeConv2D, we can run benchmarks of TransposeConv2D operator to verify performance.
Hence, in this utility, we will build the functionality to allow users and developers of deep learning frameworks to easily run benchmarks for individual operators across varying settings.
Requirements
- Benchmarks for Apache MXNet operators.
- Common combination (Fused) of operators. Conv + Relu, Conv + BatchNorm.
- Individual operator benchmarks to capture - time for operator execution (speed), memory usage.
- Fine grained individual operator benchmarks to capture - time for forward pass, time for backward pass and both.
- Ability to run operator benchmarks with default inputs or customize with user specific inputs.
- Ability to run operator benchmarks on CPU/GPU with different flavors of MXNet (mxnet-mkl, mxnet-cu90mkl etc.)
- Benchmarks for operators with varying inputs to uncover any performance issues due to skewed input data. Ex: Measuring operator performance on small input tensors, large input tensors along with average normally used tensor sizes.
- Ability to run one, group or all operator benchmarks.
- Ability to extract results in multiple usable format - Python Dictionary, JSON, CSV, MD
- Statistics:
- Mean, Median, P50, P90, P99
Design Tenets
- Defaults => Common use cases should be extremely easy, customized complex use cases should be possible.
- Example: I should be able to run Add operator benchmarks without specifying any inputs and library should provide benchmarks on valid default inputs. At the same time, as a power user, I should be able to provide my own inputs such as Tensor Shapes and context to run the benchmarks.
- Minimum Learning Curve => Keep APIs same or close to native NDArray / Gluon Operators being benchmarked.
- Example: If I am doing benchmarks on nd.add(lhs, rhs) operator, interface in the benchmark utility should be similar with zero learning curve.
- Modular and Reusable
- For a programmer or an automated system
- Example: Developer using the library or integration with CI/CD
Proposed Approach
- This benchmark library will be built on top of MXNet's ND and Gluon interface.
- For each operator in ND and Gluon Block, there will be a corresponding Benchmarking operator in the library with default inputs, functionality to process results. See below example for Add operator benchmarks.
- High-level drivers are provided to run operator benchmarks in bulk. Example: run_all_mxnet_operator_benchmarks(), run_all_arithmetic_operations_benchmarks() etc.
- Results can be generated as a python dictionary/JSON/CSV for upstream system (Ex: CI, Automated Performance Monitoring System) consumption.
class MXNetOperatorBenchmarkBase(ABC): """Abstract Base class for all MXNet operator benchmarks. """ def __init__(self, ctx=mx.cpu(), warmup=10, runs=10, default_parameters={}, custom_parameters=None): self.ctx = ctx self.runs = runs self.warmup = warmup self.results = {} self.inputs = prepare_input_parameters(caller=self.__class__.__name__, default_parameters=default_parameters, custom_parameters=custom_parameters) @abstractmethod def run_benchmark(self): pass def print_benchmark_results(self): if not len(self.results): print("No benchmark results found. Run the benchmark before printing results!") return for key, val in self.results.items(): print("{} - {:.6f} seconds".format(key, val)) def get_benchmark_results(self): return self.results class Add(MXNetOperatorBenchmarkBase): """Helps to Benchmark Tensor Add operation. By default benchmark both forward and backward element_wise tensor addition of 1024*1024 tensor of precision - 'float32'. """ def __init__(self, ctx=mx.cpu(), warmup=10, runs=50, inputs=None): # Set the default Inputs default_parameters = {"lhs": (1024, 1024), "rhs": (1024, 1024), "initializer": nd.normal, "run_backward": True, "dtype": "float32"} super().__init__(ctx=ctx, warmup=warmup, runs=runs, default_parameters=default_parameters, custom_parameters=inputs) self.lhs = get_mx_ndarray(ctx=self.ctx, in_tensor=self.inputs["lhs"], dtype=self.inputs["dtype"], initializer=self.inputs["initializer"], attach_grad=self.inputs["run_backward"]) self.rhs = get_mx_ndarray(ctx=self.ctx, in_tensor=self.inputs["rhs"], dtype=self.inputs["dtype"], initializer=self.inputs["initializer"], attach_grad=self.inputs["run_backward"]) def run_benchmark(self): # Warm up, ignore execution time value _, _ = nd_forward_backward_and_time(F=nd.add, runs=self.warmup, lhs=self.lhs, rhs=self.rhs) # Run Benchmarks exe_time, _ = nd_forward_backward_and_time(F=nd.add, runs=self.runs, lhs=self.lhs, rhs=self.rhs) self.results["MX_Add_Forward_Backward_Time"] = exe_time / self.runs
Addition of new Module
We propose to add this library as a new module (opperf) under incubator-mxnet/benchmark as "incubator-mxnet/benchmark/opperf". Note that, this does not generate any user facing APIs, this is a library under incubator-mxnet/benchmark folder for general use by community.
API / User Experience
We can define 2 types of users of the library and describe API interface for each of these users.
- General User, Automated Nightly tests
- Run benchmarks on all the operators or on specific categories of operators. Use default inputs provided by the library.
- Power User, PR validation tests
- Run benchmark
USE CASE 1 - Run benchmarks for all the operators
A driver to run all the MXNet operators (NDArray and Gluon) benchmarks with default inputs and saves the final result as JSON in the provided file.
python dl-operator-benchmark/run_all_mxnet_operator_benchmarks.py --output-format json --output-file mxnet_operator_benchmark_results.json
Other Driver Script CLI Options:
- output-format :
json
ormd
for markdown file output orcsv
. - ctx : By default,
cpu
on CPU machine,gpu(0)
on GPU machine. You can override and set the global context for all operator benchmarks. Example:--ctx gpu(2)
. - dtype : By default,
float32
. You can override and set the global dtype for all operator benchmarks. Example:--dtype float64
.
USE CASE 2 - Run benchmarks for all the operators in a specific category
For example, you want to run benchmarks for all NDArray Arithmetic Operators
, the library will be providing drivers to easily run benchmarks on operators of specific categories.
from mxnet_benchmarks.nd import run_all_arithmetic_operations_benchmarks # Run all Arithmetic operations benchmarks with default input values run_all_arithmetic_operations_benchmarks()
Output for the above benchmark run, on a CPU machine, would look something like below:
MX_Add_Forward_Backward_Time - 0.015201 seconds MX_Multiply_Forward_Backward_Time - 0.021678 seconds MX_Subtract_Forward_Backward_Time - 0.016154 seconds MX_Divide_Forward_Backward_Time - 0.024327 seconds MX_Modulo_Forward_Backward_Time - 0.045726 seconds MX_Power_Forward_Backward_Time - 0.077152 seconds MX_Negative_Forward_Backward_Time - 0.014472 seconds MX_Inplace_Add_Forward_Time - 0.003824 seconds MX_Inplace_Subtract_Forward_Time - 0.004137 seconds MX_Inplace_Multiply_Forward_Time - 0.006589 seconds MX_Inplace_Division_Forward_Time - 0.003869 seconds MX_Inplace_Modulo_Forward_Time - 0.018180 seconds
Use Case 3 - Power user - Run benchmarks for specific operator
As a power user, you want to run benchmarks for nd.add
operator in MXNet, you just run the following python script.
Note that, we maintain same name and spec as the underlying MXNet operator. For example - to benchmark nd.add, we can use mxnet_benchmarks.nd.Add().
Use CASE 3.1 - Default Inputs for Operators
from mxnet_benchmarks.nd import Add # Run all Arithmetic operations benchmarks with default input values add_benchmark = Add() add_benchmark.run_benchmark() add_benchmark.print_benchmark_results()
Output for the above benchmark run, on a CPU machine, would look something like below:
MX_Add_Forward_Backward_Time - 0.015201 seconds
USE CASE 3.2 - Customize Inputs for Operators
As a power user, let us assume, you want to run benchmarks on a float64
tensor instead of a default float32
.
NOTE: Similarly, you could also specify the input tensors to use for benchmarking.
from mxnet_benchmarks.nd import Add # Run all Arithmetic operations benchmarks with default input values add_benchmark = Add(inputs={"dtype": "float64"}) add_benchmark.run_benchmark() add_benchmark.print_benchmark_results()
Output for the above benchmark run, on a CPU machine, would look something like below:
MX_Add_Forward_Backward_Time - 0.025405 seconds
NOTE: You can print the input parameters used for a benchmark as shown below.
from mxnet_benchmarks.nd import Add # Run all Arithmetic operations benchmarks with default input values add_benchmark = Add(inputs={"dtype": "float64"})print(add_benchmark.inputs)
Output
{'lhs': (1024, 1024), 'rhs': (1024, 1024), 'initializer': <function normal at 0x117b607b8>, 'run_backward': True, 'dtype': 'float64'}
Future Development and Ideas
The current proposed library is basic bare bone utility for easily running the operator benchmarks across different settings and generate the results in different formats. However, below are some ideas to evolve or build high level abstractions on top of this library:
- Graphs and insights to understand implication of various settings, such as precision/storage_type/accelerator_type/tensor shapes/etc..., on a given operator.
- Integration with tools such as MXBoard for debugging and visualization of performance bottlenecks, resource utilization and more fine grained visibility for users when training a model.
- Integration with nnvm pass for optimization, dynamic accelerator choosing and other operator level decision making capabilities.
Development Plan / Milestones
current status
See this repo for more details - https://github.com/sandeep-krishnamurthy/dl-operator-benchmark
- 134 operators are supported:
- All Gluon Layers - Activation, Loss, Normalization, Basic like Dense, Convolutions, Recurrent (RNN, LSTM, GRU)
- NDArray operators like creation, random sampling, arithmetic, logical, comparison etc...
- Timing metric - forward only, forward+backward operation.
Development plan
We will be working in 3 Phases as described below.
In Phase 1, we will target to benchmark all important and commonly used MXNet's NDArray and Gluon operators. We defined important and commonly used by users as - Operators part of image, text and graph data processing operations, operations part of standard network architecture such as ResNet, BERT and so on. We will do NDArray operations and Gluon Blocks i.e., all imperative operator benchmarks in phase 1.
NOTES: Why not Symbol Mode in Phase 1?
- Our objective is to capture the performance at basic individual operator level.
- Symbol APIs is planned to be deprecated soon for users.
- Users currently use NDArray operations or use Gluon Layers in imperative (NDArray) or hybrid mode (Symbolic).
- In Phase 2 we will be benchmarking Gluon Hybrid Layers individually that should cover the symbolic operations exposed to users.
- Also, under the hood, the kernel is same for NDArray and Symbols. hence, we are not missing any tests.
In Phase 2, we will cover the remaining operators left out from phase 1 and also include Gluon Hybrid model this indirectly covers Symbol APIs of prominent operators.
In Phase 3, based on the requirement we will add equivalent PyTorch Operator benchmarks for having neutral baseline for MXNet operator benchmarks.
We will be running benchmarks on CPU (C5.18x) and GPU (P3.2x). For GPU we will be using GPU(0) only. In Phase 1, we will be running for FP32 and dense tensor only. In Phase 2, we will benchmark other Precisions (INT64, FP64 etc...) and also add support for Sparse Tensors.
Phase 1
- Hardware
- CPU - C5.18X
- GPU - P3.2X (Single GPU)
- NDArray Operations
- Copy, CopyTo, as_in_context, asnumpy, asscalar, astype
- zeros, zeros_like, ones, ones_like, full, arange
- Transpose (T), shape_array, size_array, reshape, reshape, reshape_like, flatten, expand_dims, split, diag
- tile, pad
- sum, nansum, prod, nanprod, mean, max, min, norm
- sort, argsort, topk, argmax, argmin, argmax_channel
- add, sub, neg, mul, div, mod, pow
- iadd (+=), isub (-=), imul (*=), idiv (/=), imod (%=)
- lesser, lesser_equal, greater, greater_equal, equal, not_equal
- get_item (x[i]), set_item (x[i]=)
- slice, slice_axis, take, batch_take, pick
- one_hot
- exp, log
- sqrt, square
- concat, split, stack
- dot, batch_dot
- normal, poisson, uniform, random, randn, randint
- shuffle
- clip
- where
- abs
- Precision - FP32
- Conversion Operations
- Creation Operations
- Shape (view) change Operations
- Reduction Operations
- Sorting and Searching Operations
- Arithmetic Operations
- Inplace Arithmetic Operations
- Comparison Operations
- Indexing Operations
- Exponents and Logarithms
- Powers Operations
- Join and Split Operations
- GEMM
- Random Sampling
- Others
- Neural Network Operations
- Gluon Layers (Neural Network Operations)
- Dense, Lambda, Flatten, Embedding
- Dropout, BatchNorm
- Conv1D, Conv2D
- Conv1DTranspose, Conv2DTranspose
- MaxPool1D, MaxPool2D, AvgPool1D, AvgPool2D, GlobalMaxPool1D, GlobalMaxPool2D, GlobalAvgPool1D, GlobalAvgPool2D
- LeakyRelu, PRelu, Sigmoid, Softmax, Log_Softmax, Activation
- RNNCell, LSTMCell, GRUCell, RecurrentCell, SequentialRNNCell, BiDirectionalCell
- L1Loss, L2Loss, SigmoidBinaryCrossEntropyLoss, SoftmaxCrossEntropyLoss, KLDivLoss, HuberLoss, HingeLoss, SquaredHingeLoss, LogisticLoss, TripletLoss, CTCLoss
- Modes: Imperative (Hybrid will be added in Next Phase)
- Basic
- Convolutions
- Pooling
- Activations
- Recurrent Cells
- Loss
- Custom Operator Benchmark
Phase 2
- Other DataTypes
- INT64, INT8, FP64, FP16
- NDArray Operations
- tostype
- swapaxes, flip, depth_to_space, space_to_depth
- round, rint, fix, floor, ceil, trunc
- sin, cos, tan, arcsin, arccos, arctan, degrees, radians
- sinh, cosh, tahnh, arcsinh, arccosh, arctanh
- expm1, log10, log2, log1p
- logical_and, logical_or, logical_xor, logical_not
- rsqrt, cbrt, rcbrt, reciprocal
- exponential, gamma, generalized_negative_binomial, multinomial, negative_binomial,
- SequenceLast, SequenceMask, SequenceReverse
- unravel_index, ravel_multi_index
- Sparse
- View Operations
- Rounding Operations
- Trigonometric Operations
- Exponent and Logarithmic Operations
- Logical Operations
- Powers Operations
- Random Operations
- Sequence Operations
- Others
- Gluon
- Conv + Relu, Conv + BatchNorm (More to be added when we start this work)
- HybridLambda
- InstanceNorm, LayerNorm
- Conv3D
- Conv3DTranspose
- MaxPool3D, AvgPool3D, GlobalMaxPool3D, GlobalAvgPool3D
- , Elu, Selu, Swish
- ZoneOutCell, ResidualCell, DropoutCell
- CosineEmbeddingLoss, PoissonNLLoss
- Mode: Hybrid Mode for all layers covered in Phase 1. Additional coverage of layers as below.
- Fused Operators
- Basic
- Convolutions
- Pooling
- Activations
- Recurrent
- Loss
- Important Contrib Layers
- Other Items to be explored
- Image APIs
- Data APIs
- Metric APIs
- Initializers and Optimizers
Phase 3
Benchmark PyTorch Operators to have neutral baseline for comparing MXNet operator performance. This is yet to be discussed and finalized.
FAQs
Q1) Why not use check_speed(..) utility in MXNet test_util?
A) Supports Symbol APIs only. Do not support benchmarking NDArray, Gluon Blocks. It is a lightweight simple symbol executor and expects users to create symbol graph to execute along with inputs. The proposed library in this document is more sophisticated by supporting benchmarking operators with NDArray, Gluon Block, provide various default inputs, provide high-level drivers, provide interface for users to specify different inputs, prepare results in different formats - Python dictionary, CSV, JSON.
Q2) Why not Symbol execution? Why only NDArray and Gluon?
A) MXNet users are encouraged and are mainly using NDArray APIs or Gluon APIs. MXNet community is moving towards deprecating symbol APIs with works on numpy compatible operators. To measure what our users use and observe, we propose to use NDArray and Gluon blocks for benchmarking operators in this library.