|
| 1 | +""" |
| 2 | +.. _l-plot-export-with-dynamic-shape: |
| 3 | +
|
| 4 | +=========================================== |
| 5 | +Export with DynamicCache and dynamic shapes |
| 6 | +=========================================== |
| 7 | +
|
| 8 | +Every LLMs implemented in :epkg:`trasnformers` use cache. |
| 9 | +One of the most used is :class:`transformers.cache_utils.DynamicCache`. |
| 10 | +The cache size is dynamic to cope with the growing context. |
| 11 | +The example shows a tool which determines the dynamic shapes |
| 12 | +for :func:`torch.export.export` based on a set of valid inputs. |
| 13 | +
|
| 14 | +Simple Examples |
| 15 | +=============== |
| 16 | +
|
| 17 | +We first look at examples playing positional and names parameters |
| 18 | +to understand how :func:`torch.export.export` works. |
| 19 | +
|
| 20 | +args |
| 21 | +++++ |
| 22 | +""" |
| 23 | + |
| 24 | +import pprint |
| 25 | +import torch |
| 26 | +from onnx_diagnostic.cache_helpers import make_dynamic_cache |
| 27 | +from onnx_diagnostic.helpers import string_type |
| 28 | +from onnx_diagnostic.export import ModelInputs |
| 29 | + |
| 30 | + |
| 31 | +class Model(torch.nn.Module): |
| 32 | + def forward(self, x, y): |
| 33 | + return x + y |
| 34 | + |
| 35 | + |
| 36 | +model = Model() |
| 37 | +x = torch.randn((5, 6)) |
| 38 | +y = torch.randn((1, 6)) |
| 39 | +model(x, y) # to check it works |
| 40 | + |
| 41 | +ep = torch.export.export(model, (x, y)) |
| 42 | +print(ep) |
| 43 | + |
| 44 | +# %% |
| 45 | +# As expected there is no dynamic shapes. |
| 46 | +# We use :class:`onnx_diagnostic.export.ModelInputs` |
| 47 | +# to define them from two set of valid inputs. |
| 48 | +# These inputs must have different value for the dynamic |
| 49 | +# dimensions. |
| 50 | + |
| 51 | +inputs = [(x, y), (torch.randn((7, 8)), torch.randn((1, 8)))] |
| 52 | +mi = ModelInputs(Model(), inputs) |
| 53 | +ds = mi.guess_dynamic_shapes() |
| 54 | +pprint.pprint(ds) |
| 55 | + |
| 56 | +# %% |
| 57 | +# The function returns a tuple with two objets. |
| 58 | +# The first one for the positional arguments, the other one |
| 59 | +# for the named arguments. There is no named argements. We |
| 60 | +# we used the first result to export. |
| 61 | + |
| 62 | +ep = torch.export.export(model, (x, y), dynamic_shapes=ds[0]) |
| 63 | +print(ep) |
| 64 | + |
| 65 | +# %% |
| 66 | +# kwargs |
| 67 | +# ++++++ |
| 68 | +# |
| 69 | +# We do the same with named argments. |
| 70 | + |
| 71 | + |
| 72 | +class Model(torch.nn.Module): |
| 73 | + def forward(self, x, y): |
| 74 | + return x + y |
| 75 | + |
| 76 | + |
| 77 | +model = Model() |
| 78 | +x = torch.randn((5, 6)) |
| 79 | +y = torch.randn((1, 6)) |
| 80 | +model(x=x, y=y) # to check it works |
| 81 | + |
| 82 | +# %% |
| 83 | +# Two sets of valid inputs. |
| 84 | +inputs = [dict(x=x, y=y), dict(x=torch.randn((7, 8)), y=torch.randn((1, 8)))] |
| 85 | +mi = ModelInputs(Model(), inputs) |
| 86 | +ds = mi.guess_dynamic_shapes() |
| 87 | +pprint.pprint(ds) |
| 88 | + |
| 89 | +# %% |
| 90 | +# And we export. |
| 91 | +ep = torch.export.export(model, (), kwargs=dict(x=x, y=y), dynamic_shapes=ds[1]) |
| 92 | +print(ep) |
| 93 | + |
| 94 | +# %% |
| 95 | +# args and kwargs |
| 96 | +# +++++++++++++++ |
| 97 | +# |
| 98 | +# :func:`torch.export.export` does not like having dynami shapes |
| 99 | +# for both args and kwargs. We need to define them using one mechanism. |
| 100 | + |
| 101 | + |
| 102 | +class Model(torch.nn.Module): |
| 103 | + def forward(self, x, y): |
| 104 | + return x + y |
| 105 | + |
| 106 | + |
| 107 | +model = Model() |
| 108 | +x = torch.randn((5, 6)) |
| 109 | +y = torch.randn((1, 6)) |
| 110 | +model(x, y=y) # to check it works |
| 111 | + |
| 112 | +# %% |
| 113 | +# Two sets of valid inputs with positional and names arguments. |
| 114 | + |
| 115 | +inputs = [((x,), dict(y=y)), ((torch.randn((7, 8)),), dict(y=torch.randn((1, 8))))] |
| 116 | +mi = ModelInputs(Model(), inputs) |
| 117 | +ds = mi.guess_dynamic_shapes() |
| 118 | +pprint.pprint(ds) |
| 119 | + |
| 120 | +# %% |
| 121 | +# This does not work with :func:`torch.export.export` so |
| 122 | +# we use a method to move the positional dynamic shapes to |
| 123 | +# named one. The method relies on the signature of the |
| 124 | +# forward method. |
| 125 | + |
| 126 | +new_args, new_kwargs, new_ds = mi.move_to_kwargs(*mi.inputs[0], ds) |
| 127 | +pprint.pprint(new_ds) |
| 128 | + |
| 129 | +# %% |
| 130 | +# And we export. |
| 131 | + |
| 132 | +ep = torch.export.export(model, new_args, kwargs=new_kwargs, dynamic_shapes=new_ds[1]) |
| 133 | +print(ep) |
| 134 | + |
| 135 | +# %% |
| 136 | +# DynamicCache |
| 137 | +# ============ |
| 138 | +# |
| 139 | +# :func:`torch.export.export` serializes caches and any custom class |
| 140 | +# if these serialization functions are provided with is the case for |
| 141 | +# :class:`transformers.cache_utils.DynamicCache` and ``transformers>=4.50``. |
| 142 | +# The dynamic shapes must be provided following the serialized form. |
| 143 | + |
| 144 | + |
| 145 | +class Model(torch.nn.Module): |
| 146 | + def forward(self, cache, z): |
| 147 | + return ( |
| 148 | + z |
| 149 | + + cache.key_cache[0] |
| 150 | + + cache.key_cache[1] |
| 151 | + + cache.value_cache[0] |
| 152 | + + cache.value_cache[1] |
| 153 | + ) |
| 154 | + |
| 155 | + |
| 156 | +model = Model() |
| 157 | + |
| 158 | +n_layers = 2 |
| 159 | +bsize, nheads, slen, dim = 2, 4, 3, 7 |
| 160 | +cache = make_dynamic_cache( |
| 161 | + [ |
| 162 | + (torch.randn(bsize, nheads, slen, dim), torch.randn(bsize, nheads, slen, dim)) |
| 163 | + for i in range(n_layers) |
| 164 | + ] |
| 165 | +) |
| 166 | +z = torch.randn((1, 1, 1, 7)) |
| 167 | +model(cache, z) # to check it works. |
| 168 | + |
| 169 | +# %% |
| 170 | +# The cache looks like this: |
| 171 | + |
| 172 | +print(string_type(cache, with_shape=True)) |
| 173 | + |
| 174 | + |
| 175 | +# %% Let's create another set of inputs. |
| 176 | + |
| 177 | +cache2 = make_dynamic_cache( |
| 178 | + [ |
| 179 | + ( |
| 180 | + torch.randn(bsize + 1, nheads, slen + 1, dim + 1), |
| 181 | + torch.randn(bsize + 1, nheads, slen + 1, dim + 1), |
| 182 | + ) |
| 183 | + for i in range(n_layers) |
| 184 | + ] |
| 185 | +) |
| 186 | +inputs = [ |
| 187 | + (cache, z), |
| 188 | + (cache2, torch.randn((1, 1, 1, 8))), |
| 189 | +] |
| 190 | + |
| 191 | +# %% |
| 192 | +# And the first set of inputs looks like: |
| 193 | +print(string_type(inputs[0], with_shape=True)) |
| 194 | + |
| 195 | +# %% |
| 196 | +# We can now compute the dynamic shapes. |
| 197 | + |
| 198 | +mi = ModelInputs(Model(), inputs) |
| 199 | +ds = mi.guess_dynamic_shapes() |
| 200 | +pprint.pprint(ds) |
| 201 | + |
| 202 | +# %% |
| 203 | +# And finally the export. |
| 204 | + |
| 205 | +ep = torch.export.export(model, inputs[0], dynamic_shapes=ds[0], strict=False) |
| 206 | +print(ep) |
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