Merge branch 'core' into 'main'

Move most of mpu functionality into a new "Megatron core"

See merge request ADLR/megatron-lm!462

megatron/data/gpt_dataset.py

@@ -8,7 +8,8 @@ import time
 import numpy as np
 import torch
 
-from megatron import mpu, print_rank_0
+from megatron import print_rank_0
+from megatron.core import mpu
 from megatron.data.blendable_dataset import BlendableDataset
 from megatron.data.dataset_utils import get_datasets_weights_and_num_samples
 from megatron.data.dataset_utils import get_train_valid_test_split_

megatron/data/orqa_wiki_dataset.py

@@ -9,7 +9,8 @@ import random
 import torch
 from torch.utils.data import Dataset
 
-from megatron import print_rank_0, get_args, get_tokenizer, mpu
+from megatron import print_rank_0, get_args, get_tokenizer
+from megatron.core import tensor_parallel
 from megatron.data.biencoder_dataset_utils import make_attention_mask
 
 def get_open_retrieval_wiki_dataset():
@@ -32,7 +33,7 @@ def get_open_retrieval_batch(data_iterator):
 
     # Broadcast data.
     data = None if data_iterator is None else next(data_iterator)
-    data_b = mpu.broadcast_data(keys, data, datatype)
+    data_b = tensor_parallel.broadcast_data(keys, data, datatype)
 
     # Unpack.
     row_id = data_b['row_id'].long()

megatron/data/realm_dataset_utils.py

@@ -4,9 +4,10 @@ import time
 import numpy as np
 import torch
 
-from megatron import mpu, print_rank_0
+from megatron import print_rank_0
+from megatron.core import mpu, tensor_parallel
 from megatron.data.dataset_utils import create_masked_lm_predictions, pad_and_convert_to_numpy
-from megatron import get_args, get_tokenizer, print_rank_0, mpu
+from megatron import get_args, get_tokenizer, print_rank_0
 
 
 def get_one_epoch_dataloader(dataset, micro_batch_size=None):
@@ -47,7 +48,7 @@ def get_ict_batch(data_iterator):
         data = None
     else:
         data = next(data_iterator)
-    data_b = mpu.broadcast_data(keys, data, datatype)
+    data_b = tensor_parallel.broadcast_data(keys, data, datatype)
 
     # Unpack.
     query_tokens = data_b['query_tokens'].long()

megatron/data/realm_index.py

@@ -7,7 +7,7 @@ import numpy as np
 import torch
 
 from megatron import get_args
-from megatron import mpu
+from megatron.core import mpu
 
 
 def detach(tensor):
@@ -50,10 +50,10 @@ class OpenRetreivalDataStore(object):
     def load_from_file(self):
         """Populate members from instance saved to file"""
 
-        if mpu.is_unitialized() or mpu.get_data_parallel_rank() == 0:
+        if not mpu.model_parallel_is_initialized() or mpu.get_data_parallel_rank() == 0:
             print("\n> Unpickling BlockData", flush=True)
         state_dict = pickle.load(open(self.embedding_path, 'rb'))
-        if mpu.is_unitialized() or mpu.get_data_parallel_rank() == 0:
+        if not mpu.model_parallel_is_initialized() or mpu.get_data_parallel_rank() == 0:
             print(">> Finished unpickling BlockData\n", flush=True)
 
         self.embed_data = state_dict['embed_data']
@@ -137,7 +137,7 @@ class FaissMIPSIndex(object):
         except ImportError:
             raise Exception("Error: Please install faiss to use FaissMIPSIndex")
 
-        if mpu.is_unitialized() or mpu.get_data_parallel_rank() == 0:
+        if not mpu.model_parallel_is_initialized() or mpu.get_data_parallel_rank() == 0:
             print("\n> Building index", flush=True)
 
         cpu_index = faiss.IndexFlatIP(self.embed_size)
@@ -149,12 +149,12 @@ class FaissMIPSIndex(object):
             config.useFloat16 = True
             gpu_index = faiss.index_cpu_to_all_gpus(cpu_index, co=config)
             self.mips_index = faiss.IndexIDMap(gpu_index)
-            if mpu.is_unitialized() or mpu.get_data_parallel_rank() == 0:
+            if not mpu.model_parallel_is_initialized() or mpu.get_data_parallel_rank() == 0:
                 print(">> Initialized index on GPU", flush=True)
         else:
             # CPU index supports IDs so wrap with IDMap
             self.mips_index = faiss.IndexIDMap(cpu_index)
-            if mpu.is_unitialized() or mpu.get_data_parallel_rank() == 0:
+            if not mpu.model_parallel_is_initialized() or mpu.get_data_parallel_rank() == 0:
                 print(">> Initialized index on CPU", flush=True)
 
         # if we were constructed with a BlockData, then automatically load it
@@ -199,7 +199,7 @@ class FaissMIPSIndex(object):
 
         self.mips_index.add_with_ids(embeds_arr, indices_arr)
 
-        if mpu.is_unitialized() or mpu.get_data_parallel_rank() == 0:
+        if not mpu.model_parallel_is_initialized() or mpu.get_data_parallel_rank() == 0:
             print(">>> Finished adding block data to index", flush=True)
 
     def search_mips_index(self, query_embeds, top_k, reconstruct=True):

megatron/global_vars.py

@@ -4,8 +4,6 @@
 
 import os
 import sys
-from functools import reduce
-import operator
 import torch
 
 from megatron import dist_signal_handler
@@ -20,7 +18,6 @@ _GLOBAL_TENSORBOARD_WRITER = None
 _GLOBAL_ADLR_AUTORESUME = None
 _GLOBAL_TIMERS = None
 _GLOBAL_SIGNAL_HANDLER = None
-_GLOBAL_MEMORY_BUFFER = None
 
 def get_args():
     """Return arguments."""
@@ -70,11 +67,6 @@ def get_signal_handler():
     return _GLOBAL_SIGNAL_HANDLER
 
 
-def get_global_memory_buffer():
-    _ensure_var_is_initialized(_GLOBAL_MEMORY_BUFFER, 'global memory buffer')
-    return _GLOBAL_MEMORY_BUFFER
-
-
 def _set_signal_handler():
     global _GLOBAL_SIGNAL_HANDLER
     _ensure_var_is_not_initialized(_GLOBAL_SIGNAL_HANDLER, 'signal handler')
@@ -96,7 +88,6 @@ def set_global_variables(args):
     _set_tensorboard_writer(args)
     _set_adlr_autoresume(args)
     _set_timers(args)
-    _set_global_memory_buffer()
 
     if args.exit_signal_handler:
         _set_signal_handler()
@@ -176,13 +167,6 @@ def _set_timers(args):
     _GLOBAL_TIMERS = Timers(args.timing_log_level, args.timing_log_option)
 
 
-def _set_global_memory_buffer():
-    """Initialize global buffer"""
-    global _GLOBAL_MEMORY_BUFFER
-    _ensure_var_is_not_initialized(_GLOBAL_MEMORY_BUFFER, 'global memory buffer')
-    _GLOBAL_MEMORY_BUFFER = GlobalMemoryBuffer()
-
-
 def _ensure_var_is_initialized(var, name):
     """Make sure the input variable is not None."""
     assert var is not None, '{} is not initialized.'.format(name)
@@ -194,22 +178,3 @@ def _ensure_var_is_not_initialized(var, name):
 
 
 
-class GlobalMemoryBuffer:
-    """Global buffer to avoid dynamic memory allocations.
-    Caller should ensure that buffers of the same name 
-    are not used concurrently."""
-
-    def __init__(self):
-        self.buffer = {}
-
-    def get_tensor(self, tensor_shape, dtype, name):
-        required_len = reduce(operator.mul, tensor_shape, 1)
-        if self.buffer.get((name, dtype), None) is None or \
-                self.buffer[(name, dtype)].numel() < required_len:
-            self.buffer[(name, dtype)] = \
-                torch.empty(required_len,
-                            dtype=dtype,
-                            device=torch.cuda.current_device(),
-                            requires_grad=False)
-
-        return self.buffer[(name, dtype)][0:required_len].view(*tensor_shape)

megatron/indexer.py

@@ -4,7 +4,7 @@ import torch
 import torch.distributed as dist
 
 from megatron import get_args, print_rank_0
-from megatron import mpu
+from megatron.core import mpu
 from megatron.checkpointing import load_biencoder_checkpoint
 from megatron.data.orqa_wiki_dataset import get_open_retrieval_wiki_dataset
 from megatron.data.orqa_wiki_dataset import get_open_retrieval_batch

megatron/initialize.py

@@ -14,12 +14,10 @@ from megatron import fused_kernels
 from megatron import get_adlr_autoresume
 from megatron import get_args
 from megatron import get_tensorboard_writer
-from megatron import mpu
+from megatron.core import mpu, tensor_parallel
 from megatron.arguments import (parse_args, validate_args)
 from megatron.checkpointing import load_args_from_checkpoint
 from megatron.global_vars import set_global_variables
-from megatron.mpu import (set_tensor_model_parallel_rank,
-                          set_tensor_model_parallel_world_size)
 from megatron.model.transformer import bias_dropout_add_fused_train
 from megatron.model.fused_bias_gelu import bias_gelu
 
@@ -64,13 +62,14 @@ def initialize_megatron(extra_args_provider=None, args_defaults={},
 
     args = get_args()
     if  args.lazy_mpu_init:
+        # TODO is this still a necessary option?
         args.use_cpu_initialization=True
         # delayed initialization of DDP-related stuff
         # We only set basic DDP globals
-        set_tensor_model_parallel_world_size(args.tensor_model_parallel_size)
+        mpu.set_tensor_model_parallel_world_size(args.tensor_model_parallel_size)
         # and return function for external DDP manager
         # to call when it has DDP initialized
-        set_tensor_model_parallel_rank(args.rank)    
+        mpu.set_tensor_model_parallel_rank(args.rank)
         return finish_mpu_init
     else:
         # Megatron's MPU is the master. Complete initialization right away.
@@ -146,7 +145,7 @@ def _compile_dependencies():
 
 
 def _initialize_distributed():
-    """Initialize torch.distributed and mpu."""
+    """Initialize torch.distributed and core model parallel."""
     args = get_args()
 
     device_count = torch.cuda.device_count()
@@ -187,6 +186,11 @@ def _initialize_distributed():
                                            args.pipeline_model_parallel_size,
                                            args.virtual_pipeline_model_parallel_size,
                                            args.pipeline_model_parallel_split_rank)
+            if args.rank == 0:
+                print(f'> initialized tensor model parallel with size '
+                      f'{mpu.get_tensor_model_parallel_world_size()}')
+                print(f'> initialized pipeline model parallel with size '
+                      f'{mpu.get_pipeline_model_parallel_world_size()}')
 
 
 def _init_autoresume():
@@ -210,7 +214,7 @@ def _set_random_seed(seed_, data_parallel_random_init=False):
         np.random.seed(seed)
         torch.manual_seed(seed)
         if torch.cuda.device_count() > 0:
-            mpu.model_parallel_cuda_manual_seed(seed)
+            tensor_parallel.model_parallel_cuda_manual_seed(seed)
     else:
         raise ValueError('Seed ({}) should be a positive integer.'.format(seed))
 

megatron/model/bert_model.py

@@ -5,7 +5,7 @@
 import torch
 
 from megatron import get_args
-from megatron import mpu
+from megatron.core import tensor_parallel
 from megatron.model.enums import AttnMaskType
 from megatron.model.language_model import parallel_lm_logits
 from megatron.model.language_model import get_language_model
@@ -61,7 +61,7 @@ class BertLMHead(MegatronModule):
         args = get_args()
 
         self.bias = torch.nn.Parameter(torch.zeros(mpu_vocab_size))
-        mpu.set_tensor_model_parallel_attributes(self.bias, True, 0, 1)
+        tensor_parallel.set_tensor_model_parallel_attributes(self.bias, True, 0, 1)
         self.parallel_output = parallel_output
 
         self.dense = get_linear_layer(hidden_size, hidden_size, init_method)
@@ -110,9 +110,9 @@ def post_language_model_processing(lm_output, pooled_output,
         # lm_logits : [s, b, h] and lm_labels: [s, b]
         if fp16_lm_cross_entropy:
             assert lm_logits.dtype == torch.half
-            lm_loss = mpu.vocab_parallel_cross_entropy(lm_logits, lm_labels)
+            lm_loss = tensor_parallel.vocab_parallel_cross_entropy(lm_logits, lm_labels)
         else:
-            lm_loss = mpu.vocab_parallel_cross_entropy(lm_logits.float(),
+            lm_loss = tensor_parallel.vocab_parallel_cross_entropy(lm_logits.float(),
                                                         lm_labels)
         # [s, b] => [b s]
         lm_loss = lm_loss.transpose(0,1).contiguous()

megatron/model/biencoder_model.py

@@ -2,11 +2,11 @@ import os
 import torch
 import sys
 
-from megatron import get_args, print_rank_0
+from megatron import get_args, print_rank_0, get_tokenizer
+from megatron.core import mpu
 from megatron.checkpointing import fix_query_key_value_ordering
 from megatron.checkpointing import get_checkpoint_tracker_filename
 from megatron.checkpointing import get_checkpoint_name
-from megatron import mpu, get_tokenizer
 from megatron.model.bert_model import bert_position_ids
 from megatron.model.enums import AttnMaskType
 from megatron.model.language_model import get_language_model

megatron/model/classification.py

@@ -5,7 +5,6 @@
 import torch
 
 from megatron import get_args, print_rank_last
-from megatron import mpu
 from megatron.model.enums import AttnMaskType
 from megatron.model.bert_model import bert_extended_attention_mask, bert_position_ids
 from megatron.model.language_model import get_language_model

megatron/model/distributed.py

@@ -8,7 +8,7 @@ import torch
 from torch._utils import _flatten_dense_tensors, _unflatten_dense_tensors
 
 from megatron import get_args
-from megatron import mpu
+from megatron.core import mpu
 from .module import MegatronModule
 
 

megatron/model/fused_layer_norm.py

@@ -10,7 +10,7 @@ from torch.nn.parameter import Parameter
 from torch.nn import init
 import importlib
 
-from megatron.mpu import make_viewless_tensor
+from megatron.core.utils import make_viewless_tensor
 
 try:
     from apex.contrib.layer_norm.layer_norm import FastLayerNormFN

megatron/model/gpt_model.py

@@ -5,7 +5,7 @@
 import torch
 
 from megatron import get_args
-from megatron import mpu
+from megatron.core import tensor_parallel
 from .module import MegatronModule
 
 from .enums import AttnMaskType
@@ -33,9 +33,9 @@ def post_language_model_processing(lm_output, labels, logit_weights,
         labels = labels.transpose(0,1).contiguous()
         if fp16_lm_cross_entropy:
             assert output.dtype == torch.half
-            loss = mpu.vocab_parallel_cross_entropy(output, labels)
+            loss = tensor_parallel.vocab_parallel_cross_entropy(output, labels)
         else:
-            loss = mpu.vocab_parallel_cross_entropy(output.float(), labels)
+            loss = tensor_parallel.vocab_parallel_cross_entropy(output.float(), labels)
         
         # [s b] => [b, s]
         loss = loss.transpose(0,1).contiguous()

megatron/model/language_model.py

@@ -6,7 +6,7 @@ import torch
 import torch.nn.functional as F
 
 from megatron import get_args
-from megatron import mpu
+from megatron.core import mpu, tensor_parallel
 from .module import MegatronModule
 from megatron.model.enums import LayerType, AttnMaskType
 from megatron.model.transformer import ParallelTransformer
@@ -26,20 +26,23 @@ def parallel_lm_logits(input_, word_embeddings_weight, parallel_output,
         async_grad_allreduce = args.async_tensor_model_parallel_allreduce and \
             model_parallel and not args.sequence_parallel
     else:
-        input_parallel = mpu.copy_to_tensor_model_parallel_region(input_)
+        input_parallel = tensor_parallel.copy_to_tensor_model_parallel_region(input_)
         async_grad_allreduce = False
 
     # Matrix multiply.
-    logits_parallel = mpu.LinearWithGradAccumulationAndAsyncCommunication.apply(
-        input_parallel, word_embeddings_weight, bias,
-        args.gradient_accumulation_fusion,
-        async_grad_allreduce, args.sequence_parallel)
+    logits_parallel = tensor_parallel.linear_with_grad_accumulation_and_async_allreduce(
+        input=input_parallel,
+        weight=word_embeddings_weight,
+        bias=bias,
+        gradient_accumulation_fusion=args.gradient_accumulation_fusion,
+        async_grad_allreduce=async_grad_allreduce,
+        sequence_parallel_enabled=args.sequence_parallel)
     # Gather if needed.
 
     if parallel_output:
         return logits_parallel
 
-    return mpu.gather_from_tensor_model_parallel_region(logits_parallel)
+    return tensor_parallel.gather_from_tensor_model_parallel_region(logits_parallel)
 
 
 def get_language_model(num_tokentypes, add_pooler,
@@ -103,7 +106,7 @@ class Pooler(MegatronModule):
         # gather data along sequence dimensions
         # same pooler is run on all tensor parallel nodes
         if self.sequence_parallel:
-            hidden_states = mpu.gather_from_sequence_parallel_region(
+            hidden_states = tensor_parallel.gather_from_sequence_parallel_region(
                 hidden_states,
                 tensor_parallel_output_grad=False)
 
@@ -143,9 +146,13 @@ class Embedding(MegatronModule):
         args = get_args()
 
         # Word embeddings (parallel).
-        self.word_embeddings = mpu.VocabParallelEmbedding(
+        self.word_embeddings = tensor_parallel.VocabParallelEmbedding(
             vocab_size, self.hidden_size,
-            init_method=self.init_method)
+            init_method=self.init_method,
+            params_dtype=args.params_dtype,
+            use_cpu_initialization=args.use_cpu_initialization,
+            perform_initialization=args.perform_initialization
+        )
         self._word_embeddings_key = 'word_embeddings'
 
         # Position embedding (serial).
@@ -222,8 +229,8 @@ class Embedding(MegatronModule):
 
         # Dropout.
         if self.sequence_parallel:
-            embeddings = mpu.scatter_to_sequence_parallel_region(embeddings)
-            with mpu.get_cuda_rng_tracker().fork():
+            embeddings = tensor_parallel.scatter_to_sequence_parallel_region(embeddings)
+            with tensor_parallel.get_cuda_rng_tracker().fork():
                 embeddings = self.embedding_dropout(embeddings)
         else:
             embeddings = self.embedding_dropout(embeddings)

megatron/model/module.py

@@ -7,7 +7,7 @@ from torch.autograd import Variable
 from torch.nn.parameter import Parameter
 
 from megatron import get_args
-from megatron import mpu
+from megatron.core import mpu, tensor_parallel
 
 
 _FLOAT_TYPES = (torch.FloatTensor, torch.cuda.FloatTensor)
@@ -76,9 +76,12 @@ class MegatronModule(torch.nn.Module):
             self._word_embeddings_for_head_key = 'word_embeddings_for_head'
             # set word_embeddings weights to 0 here, then copy first
             # stage's weights using all_reduce below.
-            self.word_embeddings = mpu.VocabParallelEmbedding(
+            self.word_embeddings = tensor_parallel.VocabParallelEmbedding(
                 args.padded_vocab_size, args.hidden_size,
-                init_method=init_method_normal(args.init_method_std))
+                init_method=init_method_normal(args.init_method_std),
+                params_dtype=args.params_dtype,
+                use_cpu_initialization=args.use_cpu_initialization,
+                perform_initialization=args.perform_initialization)
             self.word_embeddings.weight.data.fill_(0)
             self.word_embeddings.weight.shared = True
 

megatron/model/multiple_choice.py

@@ -5,7 +5,6 @@
 import torch
 
 from megatron import get_args, print_rank_last
-from megatron import mpu
 from megatron.model.enums import AttnMaskType
 from megatron.model.bert_model import bert_extended_attention_mask, bert_position_ids
 from megatron.model.language_model import get_language_model

megatron/model/realm_model.py

@@ -5,7 +5,7 @@ from megatron import get_args, print_rank_0
 from megatron.checkpointing import get_checkpoint_tracker_filename, get_checkpoint_name
 from megatron.model import BertModel
 from .module import MegatronModule
-from megatron import mpu
+from megatron.core import mpu
 from megatron.model.enums import AttnMaskType
 from megatron.model.utils import get_linear_layer
 from megatron.model.utils import init_method_normal

megatron/model/t5_model.py

@@ -4,10 +4,8 @@
 
 import torch
 
-from megatron import (
-    get_args,
-    mpu
-)
+from megatron import get_args
+from megatron.core import tensor_parallel
 from megatron.model.enums import AttnMaskType
 from megatron.model.language_model import parallel_lm_logits, get_language_model
 from megatron.model.transformer import LayerNorm
@@ -151,9 +149,9 @@ class T5Model(MegatronModule):
                 lm_labels = lm_labels.transpose(0,1).contiguous()
                 if self.fp16_lm_cross_entropy:
                     assert lm_logits.dtype == torch.half
-                    lm_loss = mpu.vocab_parallel_cross_entropy(lm_logits, lm_labels)
+                    lm_loss = tensor_parallel.vocab_parallel_cross_entropy(lm_logits, lm_labels)
                 else:
-                    lm_loss = mpu.vocab_parallel_cross_entropy(lm_logits.float(),
+                    lm_loss = tensor_parallel.vocab_parallel_cross_entropy(lm_logits.float(),
                                                                                 lm_labels)
                 # [s b] => [b s]
                 lm_loss = lm_loss.transpose(0,1).contiguous()

megatron/model/transformer.py

@@ -6,9 +6,9 @@ from contextlib import nullcontext
 import torch
 import torch.nn.functional as F
 
-from megatron import get_timers, get_args, get_global_memory_buffer
-from megatron import mpu
+from megatron import get_timers, get_args, core
 from .module import MegatronModule
+from megatron.core import mpu, tensor_parallel
 from megatron.model.enums import AttnMaskType, ModelType, LayerType, AttnType
 from megatron.model import LayerNorm
 from megatron.model.fused_softmax import FusedScaleMaskSoftmax
@@ -52,6 +52,17 @@ class DropPath(MegatronModule):
         output = hidden_state.div(keep_prob) * random_tensor
         return output
 
+def _args_to_kwargs():
+    args = get_args()
+
+    common_kwargs = {
+        "params_dtype": args.params_dtype,
+        "use_cpu_initialization": args.use_cpu_initialization,
+        "perform_initialization": args.perform_initialization,
+        "gradient_accumulation_fusion": args.gradient_accumulation_fusion,
+        "sequence_parallel_enabled": args.sequence_parallel,
+    }
+    return common_kwargs
 
 class ParallelMLP(MegatronModule):
     """MLP.
@@ -65,13 +76,16 @@ class ParallelMLP(MegatronModule):
         super(ParallelMLP, self).__init__()
         args = get_args()
 
+
         # Project to 4h.
-        self.dense_h_to_4h = mpu.ColumnParallelLinear(
+        self.dense_h_to_4h = tensor_parallel.ColumnParallelLinear(
             args.hidden_size,
             args.ffn_hidden_size,
             gather_output=False,
             init_method=init_method,
-            skip_bias_add=True)
+            skip_bias_add=True,
+            async_tensor_model_parallel_allreduce=args.async_tensor_model_parallel_allreduce,
+            **_args_to_kwargs())
 
         self.bias_gelu_fusion = args.bias_gelu_fusion
         self.activation_func = F.gelu
@@ -81,12 +95,13 @@ class ParallelMLP(MegatronModule):
             self.activation_func = erf_gelu
 
         # Project back to h.
-        self.dense_4h_to_h = mpu.RowParallelLinear(
+        self.dense_4h_to_h = tensor_parallel.RowParallelLinear(
             args.ffn_hidden_size,
             args.hidden_size,
             input_is_parallel=True,
             init_method=output_layer_init_method,
-            skip_bias_add=True)
+            skip_bias_add=True,
+            **_args_to_kwargs())
 
     def forward(self, hidden_states):
 
@@ -174,11 +189,11 @@ class CoreAttention(MegatronModule):
 
         # Per attention head and per partition values.
         world_size = mpu.get_tensor_model_parallel_world_size()
-        self.hidden_size_per_partition = mpu.divide(projection_size,
+        self.hidden_size_per_partition = core.utils.divide(projection_size,
                                                            world_size)
-        self.hidden_size_per_attention_head = mpu.divide(
+        self.hidden_size_per_attention_head = core.utils.divide(
             projection_size, args.num_attention_heads)
-        self.num_attention_heads_per_partition = mpu.divide(
+        self.num_attention_heads_per_partition = core.utils.divide(
             args.num_attention_heads, world_size)
 
         coeff = None
@@ -221,7 +236,7 @@ class CoreAttention(MegatronModule):
                                    output_size[0] * output_size[1], -1)
 
         # preallocting input tensor: [b * np, sq, sk]
-        matmul_input_buffer = get_global_memory_buffer().get_tensor(
+        matmul_input_buffer = mpu.get_global_memory_buffer().get_tensor(
             (output_size[0]*output_size[1], output_size[2], output_size[3]),
             query_layer.dtype, "mpu")
 
@@ -247,7 +262,7 @@ class CoreAttention(MegatronModule):
         # seem a bit unusual, but is taken from the original Transformer paper.
 
         if not self.sequence_parallel:
-            with mpu.get_cuda_rng_tracker().fork():
+            with tensor_parallel.get_cuda_rng_tracker().fork():
                 attention_probs = self.attention_dropout(attention_probs)
         else:
             attention_probs = self.attention_dropout(attention_probs)
@@ -312,43 +327,51 @@ class ParallelAttention(MegatronModule):
 
         # Per attention head and per partition values.
         world_size = mpu.get_tensor_model_parallel_world_size()
-        self.hidden_size_per_attention_head = mpu.divide(
+        self.hidden_size_per_attention_head = core.utils.divide(
             projection_size, args.num_attention_heads)
-        self.num_attention_heads_per_partition = mpu.divide(
+        self.num_attention_heads_per_partition = core.utils.divide(
             args.num_attention_heads, world_size)
 
         # Strided linear layer.
         if attention_type == AttnType.self_attn:
-            self.query_key_value = mpu.ColumnParallelLinear(
+            self.query_key_value = tensor_parallel.ColumnParallelLinear(
                 args.hidden_size,
                 3 * projection_size,
                 gather_output=False,
-                init_method=init_method)
+                init_method=init_method,
+                async_tensor_model_parallel_allreduce=args.async_tensor_model_parallel_allreduce,
+                **_args_to_kwargs())
         else:
             assert attention_type == AttnType.cross_attn
-            self.query = mpu.ColumnParallelLinear(
+            self.query = tensor_parallel.ColumnParallelLinear(
                 args.hidden_size,
                 projection_size,
                 gather_output=False,
-                init_method=init_method)
+                init_method=init_method,
+                async_tensor_model_parallel_allreduce=args.async_tensor_model_parallel_allreduce,
+                **_args_to_kwargs())
+
 
-            self.key_value = mpu.ColumnParallelLinear(
+            self.key_value = tensor_parallel.ColumnParallelLinear(
                 args.hidden_size,
                 2 * projection_size,
                 gather_output=False,
-                init_method=init_method)
+                init_method=init_method,
+                async_tensor_model_parallel_allreduce=args.async_tensor_model_parallel_allreduce,
+                **_args_to_kwargs())
 
         self.core_attention = CoreAttention(self.layer_number,
                                             self.attn_mask_type)
         self.checkpoint_core_attention = args.recompute_granularity == 'selective'
 
         # Output.
-        self.dense = mpu.RowParallelLinear(
+        self.dense = tensor_parallel.RowParallelLinear(
             projection_size,
             args.hidden_size,
             input_is_parallel=True,
             init_method=output_layer_init_method,
-            skip_bias_add=True)
+            skip_bias_add=True,
+            **_args_to_kwargs())
 
     def _checkpointed_attention_forward(self, query_layer, key_layer,
                                         value_layer, attention_mask):
@@ -362,7 +385,7 @@ class ParallelAttention(MegatronModule):
                                           value_layer, attention_mask)
             return output_
 
-        hidden_states = mpu.checkpoint(
+        hidden_states = tensor_parallel.checkpoint(
             custom_forward,
             False, query_layer, key_layer, value_layer, attention_mask)
 
@@ -415,7 +438,7 @@ class ParallelAttention(MegatronModule):
             # [sq, b, np, 3 * hn] --> 3 [sq, b, np, hn]
             (query_layer,
              key_layer,
-             value_layer) = mpu.split_tensor_along_last_dim(mixed_x_layer, 3)
+             value_layer) = tensor_parallel.split_tensor_along_last_dim(mixed_x_layer, 3)
         else:
             # Attention heads [sk, b, h] --> [sk, b, (np * 2 * hn)]
             mixed_kv_layer, _ = self.key_value(encoder_output)
@@ -428,7 +451,7 @@ class ParallelAttention(MegatronModule):
 
             # [sk, b, np, 2 * hn] --> 2 [sk, b, np, hn]
             (key_layer,
-             value_layer) = mpu.split_tensor_along_last_dim(mixed_kv_layer, 2)
+             value_layer) = tensor_parallel.split_tensor_along_last_dim(mixed_kv_layer, 2)
 
             # Attention head [sq, b, h] --> [sq, b, hp]
             query_layer, _ = self.query(hidden_states)
@@ -674,7 +697,7 @@ class ParallelTransformerLayer(MegatronModule):
             # won't result in memory savings (like the data loader, or
             # p2p_communication), it serves to document the origin of this
             # 'view' tensor.
-            output = mpu.make_viewless_tensor(inp = output,
+            output = core.utils.make_viewless_tensor(inp = output,
                                                      requires_grad = output.requires_grad,
                                                      keep_graph = True)
 
@@ -713,6 +736,58 @@ class NoopTransformerLayer(MegatronModule):
         return hidden_states.clone()
 
 
+def _get_num_layers(args, is_encoder_and_decoder_model, is_decoder=False):
+    """Compute the number of transformer layers resident on the current rank."""
+    if get_pipeline_model_parallel_world_size() > 1:
+        if is_encoder_and_decoder_model:
+            assert args.pipeline_model_parallel_split_rank is not None
+
+            # When a standalone embedding stage is used, a rank is taken from
+            # the encoder's ranks, to be used for the encoder's embedding
+            # layer. This way, the rank referenced by the 'split rank' remains
+            # the same whether or not a standalone embedding stage is used.
+            num_ranks_in_encoder = (
+                args.pipeline_model_parallel_split_rank - 1
+                if args.standalone_embedding_stage else
+                args.pipeline_model_parallel_split_rank
+            )
+            num_ranks_in_decoder = args.transformer_pipeline_model_parallel_size - num_ranks_in_encoder
+            assert args.encoder_num_layers % num_ranks_in_encoder == 0, \
+                    'encoder_num_layers (%d) must be divisible by number of ranks given to encoder (%d)' % (args.encoder_num_layers, num_ranks_in_encoder)
+            assert args.decoder_num_layers % num_ranks_in_decoder == 0, \
+                    'decoder_num_layers (%d) must be divisible by number of ranks given to decoder (%d)' % (args.decoder_num_layers, num_ranks_in_decoder)
+            if is_pipeline_stage_before_split():
+                num_layers = (
+                    0
+                    if args.standalone_embedding_stage
+                    and get_pipeline_model_parallel_rank() == 0 else
+                    args.encoder_num_layers // num_ranks_in_encoder
+                )
+            else:
+                num_layers = args.decoder_num_layers // num_ranks_in_decoder
+        else:
+            assert args.num_layers == args.encoder_num_layers
+            assert args.num_layers % args.transformer_pipeline_model_parallel_size == 0, \
+                'num_layers must be divisible by transformer_pipeline_model_parallel_size'
+
+            # When a standalone embedding stage is used, all transformer layers
+            # are divided among pipeline rank >= 1, while on pipeline rank 0,
+            # ranks either contain the input embedding layer (virtual pp rank 0),
+            # or no layers at all (virtual pp rank >= 1).
+            num_layers = (
+                0
+                if args.standalone_embedding_stage
+                and get_pipeline_model_parallel_rank() == 0 else
+                args.num_layers // args.transformer_pipeline_model_parallel_size
+            )
+    else:
+        if not is_decoder:
+            num_layers = args.encoder_num_layers
+        else:
+            num_layers = args.decoder_num_layers
+    return num_layers
+
+
 class ParallelTransformer(MegatronModule):
     """Transformer class."""
 
@@ -745,7 +820,7 @@ class ParallelTransformer(MegatronModule):
         self.sequence_parallel = args.sequence_parallel
 
         # Number of layers.
-        self.num_layers = mpu.get_num_layers(
+        self.num_layers = _get_num_layers(
             args,
             args.model_type == ModelType.encoder_and_decoder,
             layer_type == LayerType.decoder)
@@ -840,7 +915,7 @@ class ParallelTransformer(MegatronModule):
             # A method to further reduce memory usage reducing checkpoints.
             l = 0
             while l < self.num_layers:
-                hidden_states = mpu.checkpoint(
+                hidden_states = tensor_parallel.checkpoint(
                     custom(l, l + self.recompute_num_layers),
                     self.distribute_saved_activations,
                     hidden_states, attention_mask, encoder_output, enc_dec_attn_mask)
@@ -852,7 +927,7 @@ class ParallelTransformer(MegatronModule):
             # A method fully use the device memory removing redundant re-computation.
             for l in range(self.num_layers):
                 if l < self.recompute_num_layers:
-                    hidden_states = mpu.checkpoint(
+                    hidden_states = tensor_parallel.checkpoint(
                         custom(l, l + 1),
                         self.distribute_saved_activations,
                         hidden_states, attention_mask, encoder_output, enc_dec_attn_mask)
@@ -903,14 +978,14 @@ class ParallelTransformer(MegatronModule):
         #   likely redundant, since p2p_communication.py (likely originator)
         #   already creates viewless tensors. That said, make_viewless_tensor()
         #   is called here to be future-proof and corner-case-proof.
-        hidden_states = mpu.make_viewless_tensor(
+        hidden_states = core.utils.make_viewless_tensor(
             hidden_states,
             requires_grad=True,
             keep_graph=True,
         )
 
         if self.sequence_parallel:
-            rng_context = mpu.get_cuda_rng_tracker().fork()
+            rng_context = tensor_parallel.get_cuda_rng_tracker().fork()
         else:
             rng_context = nullcontext()
 

megatron/model/vision/knn_monitor.py

 import torch.nn.functional as F
 import torch
-from megatron import print_rank_0, get_args, mpu
+from megatron import print_rank_0, get_args
+from megatron.core import mpu
 from megatron.data.vit_dataset import ClassificationTransform
 from megatron.data.image_folder import ImageFolder