FRAME: Fast Roofline Analytical Modeling and Estimation

This is a roofline cost model for DNN accelerators. We support CNNs, MLPs, and Transformers workload.

What it does

• Given DNN accelerator system information (using the System class in src/system.py), where you can specify PE array shape (mxu_shape), on-chip BWs, off-chip BWs, etcs.
• Given DNN workload (e.g., model='vgg16')

FRAME generate a table of layer-wise latency and memory usage information as well as a roofline figure, as shown in the following

How to use it

Interactive Design Space Exploration

You are welcome to play with it by notebook/dnn_accel_playground.ipynb.

We also provide a colab version for quick trial

How to plug into you experiments

Use the analyze_model.

model_df, _ = analyze_model()

model_df contains a layer-by-layer analysis results. The parameters of analyze_modelare described as follows.

Parameters

Algorithmic Parameters

Basic Parameters

• use_attn_model: Set to True if you want to use the pre-defined attention-based language model configuration that we provide.
• head, hidden_size, ff_hidden_size: If use_attn_model == False, these variable will be ignored. head:number of head. hidden_size: hidden_size of key/query/value projection. ff_hidden_size: hiddden_size of the feedforward layers
• custom_model: If you don't want to use the pre-defined bert model
  1. Set use_attn_model to False
  2. Set custom_model to custom
  3. Create a custom.csv model configuration in data/model. You can use data/model/alexnet.csv as an template.
• batch_size: Batch size

Sparsity-specific Parameters

• custom_sparsity: Set to False if

  1. you would not like to explore sparsity or
  2. if you would like to explore uniform sparsity on all the layers, i.e., all the layers have density defined by the following three parameters density_input, density_weight, density_output.
  • if you set custom_sparsty to False, you can specify you customized layer-by-layer sparsity in data/sparsity/custom.csv (assuming you model is named custom)

• density_input: Density of input tensor. Set to 1.0 if considering dense.

• density_weight: Density of weight tensor. Set to 1.0 if considering dense.

• density_output: Density of output tensor. Set to 1.0 if considering dense.

• compress_mem: Set to True, if you want to model the fact of memory saving when model has sparsity. If set to False, then it would model the fact that model is saved in un-compressed format.

• skip_compute: Set to True, if you want to model the fact of compute saving (by skipping 0 multiplication) when model has sparsity. If set to False, then it would model the fact that all the 0-multiplications are executed.

• skip_compute_on_noopt_output: Set to True, if you want to model a more clever control which skip to computation when knowing the output is going to be ignored anyway. This would be effective when we are sparsifying the operation with masking the output. That is if we know the output is going to be masked anyway, we skip the computation.

Attention model -specific Parameter

• attn_method: The attention method. You can choose from vanilla, sparse (sparse transformer-like), lowrank (Linformer-like), kernel (Performer-like).
• low_rank_ratio: The low rank projection ratio, if you pick lowrank method.
• spattn_density: Sparse attention density, if you pick sparse method.
• m_ratio: The kernel approximation projection ratio, if you pick kernel method.
• seq_len: Sequence length.

System Parameters

• onchip_mem_bw: On-chip memory bandwidth (GB/s)
• offchip_mem_bw: Off-chip memory bandwidth (GB/s)
• flops: The compute capacity. Number of floating point operation per seconds. (TFLOPs/s)
• frequency: The frequency of the system. (MHz/s)
• bits: The bits per elements: Can choose from int8,bg16, f32
• compute_efficiency: The efficiency of the compute unit. Default as 1.0.
• memory_efficiency: The efficiency of the memory accesss. Default as 1.0.
• use_flops: Set to True, if you want to use flops to indicate the compute capacity. Then this will consider the ideal case. If you want to explore the impact of the shape of the PE (processing elements) array, then set use_flops to False and specfiy the PE array shape by the following parameters.
• mxu_height: Height of PE array.
• mxu_width: Width of PE array.
• mxu_instance: Number of PE arrays.
  • These three parameters will creste mxu_instance of PE arrays. Each PE array hasmxu_height x mxu_width PEs.

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Contributors

• Sheng-Chun (Felix) Kao
• Suvinay Subramanian
• Abhimanyu Bambhaniya
• Tushar Krishna

Citation

@software{frame,
  author = {Kao, Sheng-Chun and Subramanian, Suvinay and Bambhaniya, Abhimanyu and Krishna, Tushar},
  title = {{FRAME: Fast Roofline Analytical Modeling and Estimation}},
  url = {https://github.com/maestro-project/frame},
  version = {1.0.0},
  year = {2022}
}