rocm_jax/jax/experimental/custom_partitioning.py
Peter Hawkins 320d531521 Increase the minimum jaxlib version to 0.3.22.
The minimum xla_extension_version is now 98 and the minimum mlir_api_version is now 32.
2022-10-27 10:24:11 -04:00

275 lines
10 KiB
Python

# Copyright 2018 The JAX Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Any, Callable, Tuple
import jax
from jax import core
from jax import tree_util
from jax import linear_util as lu
from jax.experimental import pjit
from jax._src.lib.mlir.dialects import mhlo
from jax._src.lib.mlir import ir
import jax.interpreters.pxla as pxla
from jax.interpreters import mlir
from jax.interpreters import xla
from jax.interpreters import partial_eval as pe
from jax._src import custom_api_util
from jax._src.lib import xla_client as xc
from jax._src.api_util import flatten_fun_nokwargs
import weakref
class _ShardingCallbackInfo:
def __init__(self, propagate_user_sharding, partition, to_mesh_pspec_sharding,
infer_sharding_from_operands, module_context, mesh):
self.propagate_user_sharding = propagate_user_sharding
self.partition = partition
self.to_mesh_pspec_sharding = to_mesh_pspec_sharding
self.infer_sharding_from_operands = infer_sharding_from_operands
self.module_context = module_context
self.mesh = mesh
_sharding_callbacks = weakref.WeakValueDictionary() # type: ignore
_CUSTOM_PARTITIONING_CALL_NAME = "CustomSPMDPartitioning"
def _to_jax_shape(s):
return jax.core.ShapedArray(s.dimensions(), s.numpy_dtype())
def _custom_partitioning_propagate_user_sharding(sharding, shape, backend_string):
return _sharding_callbacks[backend_string].propagate_user_sharding(sharding, shape)
def _custom_partitioning_partition(arg_shapes, arg_shardings, result_shape,
result_sharding, backend_string):
info = _sharding_callbacks[backend_string]
lower_fn, result_sharding, arg_shardings = info.partition(
[_to_jax_shape(s) for s in arg_shapes],
[info.to_mesh_pspec_sharding(s.to_proto()) for s in arg_shardings],
_to_jax_shape(result_shape),
info.to_mesh_pspec_sharding(result_sharding.to_proto()))
module_context = info.module_context
def to_hlo_sharding(sharding, shape):
return xc.HloSharding.from_proto(
sharding._to_xla_op_sharding(len(shape.dimensions())))
result_sharding = to_hlo_sharding(result_sharding, result_shape)
arg_shardings = [
to_hlo_sharding(sharding, s)
for sharding, s in zip(arg_shardings, arg_shapes)
]
tiled_args = [
_to_jax_shape(sharding.tile(s))
for sharding, s in zip(arg_shardings, arg_shapes)
]
closed_jaxpr = jax.make_jaxpr(
lower_fn, axis_env=list(info.mesh.shape.items()))(*tiled_args)
axis_context = mlir.SPMDAxisContext(info.mesh)
built = mlir.build_xla_computation_helper(
closed_jaxpr,
name="tmp_xla_computation",
platform=module_context.platform,
backend_or_name=module_context.backend_or_name,
axis_context=axis_context.extend_manual(frozenset(info.mesh.axis_names)))
return built, arg_shardings, result_sharding
def _custom_partitioning_infer_sharding_from_operands(arg_shapes, arg_shardings,
shape, backend_string):
info = _sharding_callbacks[backend_string]
result_shape = _to_jax_shape(shape)
result = info.infer_sharding_from_operands(
[_to_jax_shape(s) for s in arg_shapes],
[info.to_mesh_pspec_sharding(s.to_proto()) for s in arg_shardings],
result_shape)
return xc.HloSharding.from_proto(
result._to_xla_op_sharding(len(result_shape.shape)))
custom_partitioning_p = core.Primitive("custom_partitioning")
custom_partitioning_p.multiple_results = True
def _custom_partitioning_abstract_eval(*avals, call, in_tree, out_tree,
propagate_user_sharding, partition,
infer_sharding_from_operands):
del in_tree, out_tree, propagate_user_sharding, partition, infer_sharding_from_operands
return call.out_avals
def _custom_partitioning_impl(*args, call, in_tree, out_tree, propagate_user_sharding,
partition, infer_sharding_from_operands):
del in_tree, out_tree, propagate_user_sharding, partition, infer_sharding_from_operands
return core.jaxpr_as_fun(call)(*args)
custom_partitioning_p.def_abstract_eval(_custom_partitioning_abstract_eval)
custom_partitioning_p.def_impl(_custom_partitioning_impl)
def _default_propagate_user_shardings(sharding, shape):
return sharding
@custom_api_util.register_custom_decorator_type
class custom_partitioning:
"""Inserts a CustomCallOp into the XLA graph with custom SPMD lowering rules.
Usage:
```
@custom_partitioning
def f(*args):
return ...
def propagate_user_sharding(sharding, shape):
'''Update the sharding of the op from a user's sharding.'''
def partition(arg_shapes, arg_shardings, result_shape, result_sharding):
def lower_fn(*args):
... builds computation on per-device shapes ...
# result_sharding and arg_shardings may optionally be modified and the
# partitioner will insert collectives to reshape.
return lower_fn, result_sharding, arg_shardings
def infer_sharding_from_operands(arg_shapes, arg_shardings, shape):
'''Compute the result sharding from the sharding of the operands.'''
f.def_partition(partition, propagate_user_sharding, infer_sharding_from_operands)
```
The args to def_partition are as follows:
propagate_user_sharding: Callable which takes the sharding of a user (in the dag)
and returns a suggestion for a new MeshPspecSharding. The default
implementation is just to return the suggested sharding.
partition: Callable which takes the SPMD suggested partition shapes and
partition specs and returns a per-shard lowering function and the final
input and output sharding specs (the SPMD partitioner will repartition the
inputs to match).
infer_sharding_from_operands: Callable which computes an output
MeshPspecSharding from the MeshPspecSharding chosen for each argument.
"""
def __init__(self, fun):
self.fun = fun
self.partition = None
self.propagate_user_sharding = None
self.infer_sharding_from_operands = None
__getattr__ = custom_api_util.forward_attr
def def_partition(self, partition, infer_sharding_from_operands,
propagate_user_sharding=_default_propagate_user_shardings):
self.partition = partition
self.propagate_user_sharding = propagate_user_sharding
self.infer_sharding_from_operands = infer_sharding_from_operands
return partition
def __call__(self, *args):
args_flat, in_tree = tree_util.tree_flatten(args)
flat_fun, out_tree = flatten_fun_nokwargs(lu.wrap_init(self.fun), in_tree)
in_avals = [core.raise_to_shaped(core.get_aval(x)) for x in args_flat]
debug = pe.debug_info(self.fun, in_tree, False, "custom_partitioning")
jaxpr, _, consts = pe.trace_to_jaxpr_dynamic(flat_fun, in_avals, debug)
assert not len(consts)
closed_call = core.ClosedJaxpr(pe.convert_constvars_jaxpr(jaxpr), ())
out_flat = custom_partitioning_p.bind(
*consts,
*args_flat,
call=closed_call,
partition=self.partition,
propagate_user_sharding=self.propagate_user_sharding,
infer_sharding_from_operands=self.infer_sharding_from_operands,
in_tree=in_tree,
out_tree=out_tree())
return tree_util.tree_unflatten(out_tree(), out_flat)
def _custom_partitioning_lowering_rule(ctx: mlir.LoweringRuleContext, *values,
call, in_tree, out_tree,
propagate_user_sharding, partition,
infer_sharding_from_operands):
mesh = pxla.thread_resources.env.physical_mesh
axis_context = ctx.module_context.axis_context
if isinstance(axis_context, mlir.ShardingContext):
devices = axis_context.device_assignment
elif isinstance(axis_context, mlir.SPMDAxisContext):
devices = list(axis_context.mesh.devices.flat)
else:
devices = None
if not devices or len(devices) == 1:
return mlir.lower_fun(
core.jaxpr_as_fun(call), multiple_results=True)(ctx, *values)
def to_mesh_pspec_sharding(op_sharding: xc.OpSharding):
if mesh.empty:
from jax._src.sharding import OpShardingSharding
return OpShardingSharding(devices, op_sharding)
pspec = pjit.parse_flatten_op_sharding(op_sharding,
mesh)[0].get_partition_spec()
return pjit.MeshPspecSharding(mesh, pspec)
sharding_callback_info = _ShardingCallbackInfo(propagate_user_sharding, partition,
to_mesh_pspec_sharding,
infer_sharding_from_operands,
ctx.module_context, mesh)
key = str(id(sharding_callback_info))
_sharding_callbacks[key] = sharding_callback_info
# We need to make sure `sharding_callback_info` is still alive when the SPMD
# partitioner runs so we keep it alive by attaching it to the executable.
ctx.module_context.add_keepalive(sharding_callback_info)
mlir_shapes = [mlir.aval_to_ir_types(s) for s in call.out_avals]
if len(mlir_shapes) == 1:
out_type = mlir_shapes[0]
else:
out_type = [ir.TupleType.get_tuple(mlir_shapes)]
out = mhlo.CustomCallOp(
out_type,
list(values),
call_target_name=ir.StringAttr.get(_CUSTOM_PARTITIONING_CALL_NAME),
has_side_effect=ir.BoolAttr.get(False),
api_version=mlir.i32_attr(2),
called_computations=ir.ArrayAttr.get([]),
backend_config=ir.StringAttr.get(key),
operand_layouts=None,
result_layouts=None)
if len(mlir_shapes) == 1:
return [out.result]
else:
return [
mhlo.GetTupleElementOp(out, mlir.i32_attr(i)).result
for i in range(len(mlir_shapes))
]
mlir.register_lowering(custom_partitioning_p,
_custom_partitioning_lowering_rule)
xc.register_custom_call_partitioner( # pytype: disable=module-attr
_CUSTOM_PARTITIONING_CALL_NAME,
_custom_partitioning_propagate_user_sharding,
_custom_partitioning_partition,
_custom_partitioning_infer_sharding_from_operands, True)