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| 1 | +from typing import Callable, Iterable |
| 2 | + |
| 3 | +import torch |
| 4 | +import torchvision |
| 5 | + |
| 6 | +from ppq import (BaseGraph, QuantizationOptimizationPass, |
| 7 | + QuantizationOptimizationPipeline, QuantizationSetting, |
| 8 | + TargetPlatform, TorchExecutor) |
| 9 | +from ppq.api import ENABLE_CUDA_KERNEL |
| 10 | +from ppq.executor.torch import TorchExecutor |
| 11 | +from ppq.IR.quantize import QuantableOperation |
| 12 | +from ppq.IR.search import SearchableGraph |
| 13 | +from ppq.quantization.optim import (ParameterQuantizePass, |
| 14 | + PassiveParameterQuantizePass, |
| 15 | + QuantAlignmentPass, QuantizeRefinePass, |
| 16 | + QuantizeSimplifyPass, |
| 17 | + RuntimeCalibrationPass) |
| 18 | +from ppq.quantization.quantizer import TensorRTQuantizer |
| 19 | + |
| 20 | +# ------------------------------------------------------------ |
| 21 | +# 在这个例子中,我们将向你介绍如何自定义量化优化过程,以及如何手动调用优化过程 |
| 22 | +# ------------------------------------------------------------ |
| 23 | + |
| 24 | +BATCHSIZE = 32 |
| 25 | +INPUT_SHAPE = [BATCHSIZE, 3, 224, 224] |
| 26 | +DEVICE = 'cuda' |
| 27 | +PLATFORM = TargetPlatform.TRT_INT8 |
| 28 | + |
| 29 | +# ------------------------------------------------------------ |
| 30 | +# 和往常一样,我们要创建 calibration 数据,以及加载模型 |
| 31 | +# ------------------------------------------------------------ |
| 32 | +def load_calibration_dataset() -> Iterable: |
| 33 | + return [torch.rand(size=INPUT_SHAPE) for _ in range(32)] |
| 34 | +CALIBRATION = load_calibration_dataset() |
| 35 | + |
| 36 | +def collate_fn(batch: torch.Tensor) -> torch.Tensor: |
| 37 | + return batch.to(DEVICE) |
| 38 | + |
| 39 | +model = torchvision.models.mobilenet.mobilenet_v2(pretrained=True) |
| 40 | +model = model.to(DEVICE) |
| 41 | + |
| 42 | +# ------------------------------------------------------------ |
| 43 | +# 下面,我们将向你展示如何自定义图融合过程 |
| 44 | +# 图融合过程将改变量化方案,PPQ 使用 Tensor Quantization Config |
| 45 | +# 来描述图融合的具体规则,其底层由并查集进行实现 |
| 46 | +# ------------------------------------------------------------ |
| 47 | + |
| 48 | +# ------------------------------------------------------------ |
| 49 | +# 定义我们自己的图融合过程,在这里我们将尝试进行 Conv - Clip 的融合 |
| 50 | +# 但与平常不同的是,我们将关闭 Clip 之后的量化点,保留 Conv - Clip 中间的量化 |
| 51 | +# 对于更为复杂的模式匹配,你可以参考 ppq.quantization.optim.refine.SwishFusionPass |
| 52 | +# ------------------------------------------------------------ |
| 53 | +class MyFusion(QuantizationOptimizationPass): |
| 54 | + def optimize(self, graph: BaseGraph, dataloader: Iterable, |
| 55 | + collate_fn: Callable, executor: TorchExecutor, **kwargs) -> None: |
| 56 | + |
| 57 | + # 图融合过程往往由图模式匹配开始,让我们建立一个模式匹配引擎 |
| 58 | + search_engine = SearchableGraph(graph=graph) |
| 59 | + for pattern in search_engine.pattern_matching(patterns=['Conv', 'Clip'], edges=[[0, 1]], exclusive=True): |
| 60 | + conv, relu = pattern |
| 61 | + |
| 62 | + # 匹配到图中的 conv - relu 对,接下来关闭不必要的量化点 |
| 63 | + # 首先我们检查 conv - relu 是否都是量化算子,是否处于同一平台 |
| 64 | + is_quantable = isinstance(conv, QuantableOperation) and isinstance(relu, QuantableOperation) |
| 65 | + is_same_plat = conv.platform == relu.platform |
| 66 | + |
| 67 | + if is_quantable and is_same_plat: |
| 68 | + # 将 relu 输入输出的量化全部指向 conv 输出 |
| 69 | + # 一旦调用 dominated_by 完成赋值,则调用 dominated_by 的同时 |
| 70 | + # PPQ 会将 relu.input_quant_config[0] 与 relu.output_quant_config[0] 的状态置为 OVERLAPPED |
| 71 | + # 在后续运算中,它们所对应的量化不再起作用 |
| 72 | + relu.input_quant_config[0].dominated_by = conv.output_quant_config[0] |
| 73 | + relu.output_quant_config[0].dominated_by = conv.output_quant_config[0] |
| 74 | + |
| 75 | +# ------------------------------------------------------------ |
| 76 | +# 自定义图融合的过程将会干预量化器逻辑,我们需要新建量化器 |
| 77 | +# 此处我们继承 TensorRT Quantizer,算子的量化逻辑将使用 TensorRT 的配置 |
| 78 | +# 但在生成量化管线时,我们将覆盖量化器原有的逻辑,使用我们自定义的管线 |
| 79 | +# 这样我们就可以把自定义的图融合过程放置在合适的位置上,而此时 QuantizationSetting 也不再起作用 |
| 80 | +# ------------------------------------------------------------ |
| 81 | +class MyQuantizer(TensorRTQuantizer): |
| 82 | + def build_quant_pipeline(self, setting: QuantizationSetting) -> QuantizationOptimizationPipeline: |
| 83 | + return QuantizationOptimizationPipeline([ |
| 84 | + QuantizeRefinePass(), |
| 85 | + QuantizeSimplifyPass(), |
| 86 | + ParameterQuantizePass(), |
| 87 | + MyFusion(name='My Optimization Procedure'), |
| 88 | + RuntimeCalibrationPass(), |
| 89 | + QuantAlignmentPass(), |
| 90 | + PassiveParameterQuantizePass()]) |
| 91 | + |
| 92 | +from ppq.api import quantize_torch_model, register_network_quantizer |
| 93 | +register_network_quantizer(quantizer=MyQuantizer, platform=TargetPlatform.EXTENSION) |
| 94 | + |
| 95 | +# ------------------------------------------------------------ |
| 96 | +# 如果你使用 ENABLE_CUDA_KERNEL 方法 |
| 97 | +# PPQ 将会尝试编译自定义的高性能量化算子,这一过程需要编译环境的支持 |
| 98 | +# 如果你在编译过程中发生错误,你可以删除此处对于 ENABLE_CUDA_KERNEL 方法的调用 |
| 99 | +# 这将显著降低 PPQ 的运算速度;但即使你无法编译这些算子,你仍然可以使用 pytorch 的 gpu 算子完成量化 |
| 100 | +# ------------------------------------------------------------ |
| 101 | +with ENABLE_CUDA_KERNEL(): |
| 102 | + quantized = quantize_torch_model( |
| 103 | + model=model, calib_dataloader=CALIBRATION, |
| 104 | + calib_steps=32, input_shape=INPUT_SHAPE, |
| 105 | + collate_fn=collate_fn, platform=TargetPlatform.EXTENSION, |
| 106 | + onnx_export_file='model.onnx', device=DEVICE, verbose=0) |
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