ZeRO-2 (#217)

Updates for ZeRO stage 2 + ZeRO stage 1 w. RS
Co-authored-by: Tunji Ruwase <olruwase@microsoft.com>
Co-authored-by: Samyam Rajbhandari <samyamr@microsoft.com>
Co-authored-by: Shaden Smith <ShadenTSmith@gmail.com>
Co-authored-by: Elton Zheng <eltonz@microsoft.com>
Co-authored-by: Shaden Smith <Shaden.Smith@microsoft.com>
Co-authored-by: yuxionghe <yuxhe@microsoft.com>
Co-authored-by: Arash Ashari <arashari@microsoft.com>

.gitignore

@@ -2,6 +2,7 @@
 .idea/
 *~
 *.swp
+*.log
 deepspeed/git_version_info.py
 
 # Build + installation data

DeepSpeedExamples @ 274787a1

-Subproject commit 9e2c735f5aabe48395c03a276fa7a0c51f6d3025
+Subproject commit 274787a189b265814ed75dd5ddeae2dce026ea88

README.md

 [![Build Status](https://dev.azure.com/DeepSpeedMSFT/DeepSpeed/_apis/build/status/microsoft.DeepSpeed?branchName=master)](https://dev.azure.com/DeepSpeedMSFT/DeepSpeed/_build/latest?definitionId=1&branchName=master)
 [![License MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://github.com/Microsoft/DeepSpeed/blob/master/LICENSE)
 
-[DeepSpeed](https://www.deepspeed.ai/) is a deep learning optimization library that makes distributed training easy,
-efficient, and effective.
+[DeepSpeed](https://www.deepspeed.ai/) is a deep learning optimization
+library that makes distributed training easy, efficient, and effective.
 
 <p align="center"><i><b>10x Larger Models</b></i></p>
-<p align="center"><i><b>5x Faster Training</b></i></p>
+<p align="center"><i><b>10x Faster Training</b></i></p>
 <p align="center"><i><b>Minimal Code Change</b></i></p>
 
 DeepSpeed can train deep learning models with over a hundred billion parameters on current
-generation of GPU clusters, while achieving over 5x in system performance
+generation of GPU clusters, while achieving over 10x in system performance
 compared to the state-of-art. Early adopters of DeepSpeed have already produced
 a language model (LM) with over 17B parameters called
 [Turing-NLG](https://www.microsoft.com/en-us/research/blog/turing-nlg-a-17-billion-parameter-language-model-by-microsoft),
 establishing a new SOTA in the LM category.
 
+**_For further documentation, tutorials, and technical deep-dives please see [deepspeed.ai](https://www.deepspeed.ai/)!_**
+
+
 # News
-* [Turing-NLG: A 17-billion-parameter language model by Microsoft](https://www.microsoft.com/en-us/research/blog/turing-nlg-a-17-billion-parameter-language-model-by-microsoft/)
-* [ZeRO & DeepSpeed: New system optimizations enable training models with over 100 billion parameters](https://www.microsoft.com/en-us/research/blog/zero-deepspeed-new-system-optimizations-enable-training-models-with-over-100-billion-parameters/)
+* [2020/05/19] [ZeRO-2 empowers training models as large as 170 billion parameters up to 10x faster compared to state-of-the-art](https://www.deepspeed.ai/news/2020/05/19/zero-stage2.html)
+<span style="color:dodgerblue">**[_NEW_]**</span>
+* [2020/05/19] [DeepSpeed optimizes transformer kernels to achieve world’s fastest BERT training record: 44 minutes on 1024 NVIDIA V100 GPUs](https://www.deepspeed.ai/news/2020/05/19/bert-record.html)
+<span style="color:dodgerblue">**[_NEW_]**</span>
+* [2020/02/13] [Turing-NLG: A 17-billion-parameter language model by Microsoft](https://www.microsoft.com/en-us/research/blog/turing-nlg-a-17-billion-parameter-language-model-by-microsoft/)
+* [2020/02/13] [ZeRO & DeepSpeed: New system optimizations enable training models with over 100 billion parameters](https://www.microsoft.com/en-us/research/blog/zero-deepspeed-new-system-optimizations-enable-training-models-with-over-100-billion-parameters/)
 
 
 # Table of Contents
@@ -39,93 +46,6 @@ a large model easily runs out of memory with pure data parallelism and it is
 difficult to use model parallelism. DeepSpeed addresses these challenges to
 accelerate model development *and* training.
 
-## Distributed, Effective, and Efficient Training with Ease
-The DeepSpeed API is a lightweight wrapper on [PyTorch](https://pytorch.org/). This
-means that you can use everything you love in PyTorch and without learning a new
-platform. In addition, DeepSpeed manages all of the boilerplate state-of-the-art
-training techniques, such as distributed training, mixed precision, gradient
-accumulation, and checkpoints so that you can focus on your model development. Most
-importantly, you can leverage the distinctive efficiency and effectiveness benefit of
-DeepSpeed to boost speed and scale with just a few lines of code changes to your PyTorch
-models.
-
-## Speed
-DeepSpeed achieves high performance and fast convergence through a combination of
-efficiency optimizations on compute/communication/memory/IO and effectiveness
-optimizations on advanced hyperparameter tuning and optimizers. For example:
-
-* DeepSpeed trains BERT-large to parity in 14 hours using 64 GPUs (4 DGX-2 boxes) and in
-  3.7 hours using 256 GPUs (16 DGX-2 boxes).
-
-  **BERT-large Training Times**
-
-  | Devices       | Source    | Training Time (hours) |
-  | ------------- | --------- | ---------------------:|
-  | 64 TPUs       | Google    |                    96 |
-  | 64 V100 GPUs  | DeepSpeed |                **14** |
-  | 256 V100 GPUs | NVIDIA    |                   3.9 |
-  | 256 V100 GPUs | DeepSpeed |               **3.7** |
-
-*Read more*: [BERT pre-training tutorial](https://www.deepspeed.ai/tutorials/bert-pretraining/)
-
-* DeepSpeed trains GPT2 (1.5 billion parameters) 3.75x faster than state-of-art, NVIDIA
-  Megatron on Azure GPUs.
-
-  *Read more*: [GPT tutorial](https://www.deepspeed.ai/tutorials/megatron/)
-
-
-
-## Memory efficiency
-DeepSpeed provides memory-efficient data parallelism and enables training models without
-model parallelism. For example, DeepSpeed can train models with up to 6 billion parameters on
-NVIDIA V100 GPUs with 32GB of device memory. In comparison, existing frameworks (e.g.,
-PyTorch's Distributed Data Parallel) run out of memory with 1.5 billion parameter models.
-
-DeepSpeed reduces the training memory footprint through a novel solution called Zero
-Redundancy Optimizer (ZeRO). Unlike basic data parallelism where memory states are
-replicated across data-parallel processes, ZeRO partitions model states to save
-significant memory. The current implementation (stage 1 of ZeRO) reduces memory by up to
-4x relative to the state-of-art. You can read more about ZeRO in our [paper](https://arxiv.org/abs/1910.02054).
-
-With this impressive memory reduction, early adopters of DeepSpeed have already
-produced  a language model (LM) with over 17B parameters called
-[Turing-NLG](https://www.microsoft.com/en-us/research/blog/turing-nlg-a-17-billion-parameter-language-model-by-microsoft),
-establishing a new SOTA in the LM category.
-
-
-## Scalability
-DeepSpeed supports efficient data parallelism, model parallelism, and their
-combination. ZeRO boosts the scaling capability and efficiency further.
-* DeepSpeed provides system support to run models up to 100 billion parameters,
-  10x larger than the state-of-art (8 billion NVIDIA GPT, 11 billion Google T5).
-* DeepSpeed can run large models more efficiently, up to 6x faster for models with
-  various sizes spanning 1.5B to 100B.  More specifically, the data parallelism powered by ZeRO
-  is complementary and can be combined with different types of model parallelism.  It allows
-  DeepSpeed to fit models using lower degree of model parallelism and higher batch size, offering
-  significant performance gains compared to using model parallelism alone.
-
-  *Read more*: [technical report](https://arxiv.org/abs/1910.02054)
-  and [GPT tutorial](https://www.deepspeed.ai/tutorials/megatron/)
-
-![DeepSpeed-vs-Megatron](./docs/assets/images/DeepSpeed-vs-Megatron.png)
-<p align="center">
-<em>The figure depicts system throughput improvements of DeepSpeed (combining ZeRO-powered data parallelism with model parallelism of NVIDIA Megatron-LM) over using Megatron-LM alone.</em>
-</p>
-
-
-## Fast convergence for effectiveness
-DeepSpeed supports advanced hyperparameter tuning and large batch size
-optimizers such as [LAMB](https://arxiv.org/abs/1904.00962). These improve the
-effectiveness of model training and reduce the number of samples required to
-convergence to desired accuracy.
-
-*Read more*: [Tuning tutorial](https://www.deepspeed.ai/tutorials/1Cycle/) and [BERT pre-training tutorial](https://www.deepspeed.ai/tutorials/bert-pretraining/)
-
-
-## Usability
-Only a few lines of code changes are needed to enable a PyTorch model to use DeepSpeed and ZeRO. Compared to current model parallelism libraries, DeepSpeed does not require a code redesign or model refactoring. It also does not put limitations on model dimensions (such as number of attention heads, hidden sizes, and others), batch size, or any other training parameters. For models of up to six billion parameters, you can use ZeRO-powered data parallelism conveniently without requiring model parallelism, while in contrast, standard data parallelism will run out of memory for models with more than 1.3 billion parameters. In addition, DeepSpeed conveniently supports flexible combination of ZeRO-powered data parallelism with custom model parallelisms, such as tensor slicing of NVIDIA's Megatron-LM.
-
-
 # Features
 
 Below we provide a brief feature list, see our detailed [feature

azure-pipelines.yml

@@ -35,11 +35,6 @@ jobs:
       pre-commit run --all-files
     displayName: 'Formatting checks'
 
-  - script: |
-      pip install --user pylint
-      pylint --exit-zero deepspeed/
-    displayName: 'Code linter'
-
   - script: |
       pytest --forked --verbose tests/unit/
     displayName: 'Unit tests'

deepspeed/__init__.py

@@ -6,6 +6,8 @@ from deepspeed.pt.deepspeed_light import DeepSpeedLight
 from deepspeed.pt.deepspeed_light import ADAM_OPTIMIZER, LAMB_OPTIMIZER
 from deepspeed.pt.deepspeed_lr_schedules import add_tuning_arguments
 
+import deepspeed.pt.deepspeed_checkpointing as checkpointing
+
 try:
     from deepspeed.git_version_info import git_hash, git_branch
 except ImportError:
@@ -14,7 +16,7 @@ except ImportError:
 
 # Export version information
 __version_major__ = 0
-__version_minor__ = 1
+__version_minor__ = 2
 __version_patch__ = 0
 __version__ = '.'.join(
     map(str,
@@ -33,7 +35,8 @@ def initialize(args,
                lr_scheduler=None,
                mpu=None,
                dist_init_required=None,
-               collate_fn=None):
+               collate_fn=None,
+               config_params=None):
     """Initialize the DeepSpeed Engine.
 
     Arguments:
@@ -91,7 +94,8 @@ def initialize(args,
                             lr_scheduler=lr_scheduler,
                             mpu=mpu,
                             dist_init_required=dist_init_required,
-                            collate_fn=collate_fn)
+                            collate_fn=collate_fn,
+                            config_params=config_params)
 
     return_items = [
         engine,

deepspeed/pt/deepspeed_checkpointing_config.py

+"""
+Copyright (c) Microsoft Corporation
+Licensed under the MIT license.
+"""
+
+from deepspeed.pt.deepspeed_config_utils import get_scalar_param
+
+#########################################
+#  DeepSpeed Activation Checkpointing
+#########################################
+# Activation Checkpointing Allows to save memory by only keeping a select few
+#activations for the backpropagation.
+ACTIVATION_CHKPT_FORMAT = '''
+Activation Checkpointing should be configured as:
+"session_params": {
+  "activation_checkpointing": {
+    "partitioned_activations": [true|false],
+    "number_checkpoints": 100,
+    "contiguous_memory_optimization": [true|false],
+    "cpu_checkpointing": [true|false]
+    "profile": [true|false],
+    "synchronize_checkpoint_boundary": [true|false],
+    }
+}
+'''
+
+ACT_CHKPT_PARTITION_ACTIVATIONS = 'partition_activations'
+ACT_CHKPT_PARTITION_ACTIVATIONS_DEFAULT = False
+
+ACT_CHKPT_NUMBER_CHECKPOINTS = 'number_checkpoints'
+ACT_CHKPT_NUMBER_CHECKPOINTS_DEFAULT = None
+
+ACT_CHKPT_CONTIGUOUS_MEMORY_OPTIMIZATION = 'contiguous_memory_optimization'
+ACT_CHKPT_CONTIGUOUS_MEMORY_OPTIMIZATION_DEFAULT = False
+
+ACT_CHKPT_SYNCHRONIZE_CHECKPOINT_BOUNDARY = 'synchronize_checkpoint_boundary'
+ACT_CHKPT_SYNCHRONIZE_CHECKPOINT_BOUNDARY_DEFAULT = False
+
+ACT_CHKPT_PROFILE = 'profile'
+ACT_CHKPT_PROFILE_DEFAULT = False
+
+ACT_CHKPT_CPU_CHECKPOINTING = 'cpu_checkpointing'
+ACT_CHKPT_CPU_CHECKPOINTING_DEFAULT = False
+
+ACT_CHKPT = 'activation_checkpointing'
+
+ACT_CHKPT_DEFAULT = {
+    ACT_CHKPT_PARTITION_ACTIVATIONS: ACT_CHKPT_PARTITION_ACTIVATIONS_DEFAULT,
+    ACT_CHKPT_NUMBER_CHECKPOINTS: ACT_CHKPT_NUMBER_CHECKPOINTS_DEFAULT,
+    ACT_CHKPT_CONTIGUOUS_MEMORY_OPTIMIZATION:
+    ACT_CHKPT_CONTIGUOUS_MEMORY_OPTIMIZATION_DEFAULT,
+    ACT_CHKPT_SYNCHRONIZE_CHECKPOINT_BOUNDARY:
+    ACT_CHKPT_SYNCHRONIZE_CHECKPOINT_BOUNDARY_DEFAULT,
+    ACT_CHKPT_PROFILE: ACT_CHKPT_PROFILE_DEFAULT,
+    ACT_CHKPT_CPU_CHECKPOINTING: ACT_CHKPT_CPU_CHECKPOINTING_DEFAULT
+}
+
+
+class DeepSpeedActivationCheckpointingConfig(object):
+    def __init__(self, param_dict):
+        super(DeepSpeedActivationCheckpointingConfig, self).__init__()
+
+        self.partition_activations = None
+        self.contiguous_memory_optimization = None
+        self.cpu_checkpointing = None
+        self.number_checkpoints = None
+        self.synchronize_checkpoint_boundary = None
+        self.profile = None
+
+        if ACT_CHKPT in param_dict.keys():
+            act_chkpt_config_dict = param_dict[ACT_CHKPT]
+        else:
+            act_chkpt_config_dict = ACT_CHKPT_DEFAULT
+
+        self._initialize(act_chkpt_config_dict)
+
+    """
+    For json serialization
+    """
+
+    def repr(self):
+        return self.__dict__
+
+    def _initialize(self, act_chkpt_config_dict):
+        self.partition_activations = get_scalar_param(
+            act_chkpt_config_dict,
+            ACT_CHKPT_PARTITION_ACTIVATIONS,
+            ACT_CHKPT_PARTITION_ACTIVATIONS_DEFAULT)
+
+        self.contiguous_memory_optimization = get_scalar_param(
+            act_chkpt_config_dict,
+            ACT_CHKPT_CONTIGUOUS_MEMORY_OPTIMIZATION,
+            ACT_CHKPT_CONTIGUOUS_MEMORY_OPTIMIZATION_DEFAULT)
+
+        self.cpu_checkpointing = get_scalar_param(act_chkpt_config_dict,
+                                                  ACT_CHKPT_CPU_CHECKPOINTING,
+                                                  ACT_CHKPT_CPU_CHECKPOINTING_DEFAULT)
+
+        self.number_checkpoints = get_scalar_param(act_chkpt_config_dict,
+                                                   ACT_CHKPT_NUMBER_CHECKPOINTS,
+                                                   ACT_CHKPT_NUMBER_CHECKPOINTS_DEFAULT)
+
+        self.profile = get_scalar_param(act_chkpt_config_dict,
+                                        ACT_CHKPT_PROFILE,
+                                        ACT_CHKPT_PROFILE_DEFAULT)
+
+        self.synchronize_checkpoint_boundary = get_scalar_param(
+            act_chkpt_config_dict,
+            ACT_CHKPT_SYNCHRONIZE_CHECKPOINT_BOUNDARY,
+            ACT_CHKPT_SYNCHRONIZE_CHECKPOINT_BOUNDARY_DEFAULT)

deepspeed/pt/deepspeed_config.py

@@ -8,6 +8,9 @@ import logging
 import json
 from deepspeed.pt.deepspeed_constants import *
 from deepspeed.pt.loss_scaler import INITIAL_LOSS_SCALE, SCALE_WINDOW, DELAYED_SHIFT, MIN_LOSS_SCALE
+from deepspeed.pt.deepspeed_config_utils import get_scalar_param, dict_raise_error_on_duplicate_keys
+from deepspeed.pt.deepspeed_zero_config import DeepSpeedZeroConfig
+from deepspeed.pt.deepspeed_checkpointing_config import DeepSpeedActivationCheckpointingConfig
 
 TENSOR_CORE_ALIGN_SIZE = 8
 ADAM_OPTIMIZER = 'adam'
@@ -15,13 +18,6 @@ LAMB_OPTIMIZER = 'lamb'
 DEEPSPEED_OPTIMIZERS = [ADAM_OPTIMIZER, LAMB_OPTIMIZER]
 
 
-def get_scalar_param(param_dict, param_name, param_default_value):
-    if param_name in param_dict.keys():
-        return param_dict[param_name]
-    else:
-        return param_default_value
-
-
 def get_fp16_enabled(param_dict):
     if FP16 in param_dict.keys():
         return get_scalar_param(param_dict[FP16], FP16_ENABLED, FP16_ENABLED_DEFAULT)
@@ -92,10 +88,20 @@ def get_sparse_gradients_enabled(param_dict):
     return get_scalar_param(param_dict, SPARSE_GRADIENTS, SPARSE_GRADIENTS_DEFAULT)
 
 
-def get_zero_enabled(param_dict):
+def get_zero_optimization(param_dict):
     return get_scalar_param(param_dict, ZERO_OPTIMIZATION, ZERO_OPTIMIZATION_DEFAULT)
 
 
+def get_zero_reduce_scatter(param_dict):
+    return get_scalar_param(param_dict, ZERO_REDUCE_SCATTER, ZERO_REDUCE_SCATTER_DEFAULT)
+
+
+def get_zero_max_elements_per_comm(param_dict):
+    return get_scalar_param(param_dict,
+                            ZERO_MAX_ELEMENTS_PER_COMM,
+                            ZERO_MAX_ELEMENTS_PER_COMM_DEFAULT)
+
+
 def get_allgather_size(param_dict):
     return get_scalar_param(param_dict,
                             ALLGATHER_SIZE,
@@ -204,6 +210,10 @@ def get_wall_clock_breakdown(param_dict):
                             WALL_CLOCK_BREAKDOWN_DEFAULT)
 
 
+def get_memory_breakdown(param_dict):
+    return get_scalar_param(param_dict, MEMORY_BREAKDOWN, MEMORY_BREAKDOWN_DEFAULT)
+
+
 def get_tensorboard_enabled(param_dict):
     if TENSORBOARD in param_dict.keys():
         return get_scalar_param(param_dict[TENSORBOARD],
@@ -231,10 +241,39 @@ def get_tensorboard_job_name(param_dict):
         return TENSORBOARD_JOB_NAME_DEFAULT
 
 
+'''Write deepspeed config files by modifying basic templates.
+Can be used for quicly changing parameters via command line parameters.'''
+
+
+class DeepSpeedConfigWriter:
+    def __init__(self, data=None):
+        self.data = data if data is not None else {}
+
+    def add_config(self, key, value):
+        self.data[key] = value
+
+    def load_config(self, filename):
+        self.data = json.load(open(filename,
+                                   'r'),
+                              object_pairs_hook=dict_raise_error_on_duplicate_keys)
+
+    def write_config(self, filename):
+        with open(filename, 'w') as outfile:
+            json.dump(self.data, outfile)
+
+
 class DeepSpeedConfig(object):
-    def __init__(self, json_file, mpu=None):
+    def __init__(self, json_file, mpu=None, param_dict=None):
         super(DeepSpeedConfig, self).__init__()
-        self._param_dict = json.load(open(json_file, 'r'))
+
+        if param_dict is None:
+            self._param_dict = json.load(
+                open(json_file,
+                     'r'),
+                object_pairs_hook=dict_raise_error_on_duplicate_keys)
+        else:
+            self._param_dict = param_dict
+
         try:
             self.global_rank = torch.distributed.get_rank()
             if mpu is None:
@@ -263,7 +302,14 @@ class DeepSpeedConfig(object):
         self.sparse_gradients_enabled = get_sparse_gradients_enabled(param_dict)
 
         self.allgather_size = get_allgather_size(param_dict)
-        self.zero_enabled = get_zero_enabled(param_dict)
+
+        self.zero_config = DeepSpeedZeroConfig(param_dict)
+        self.zero_optimization_stage = self.zero_config.stage
+        self.zero_enabled = self.zero_optimization_stage > 0
+
+        self.activation_checkpointing_config = DeepSpeedActivationCheckpointingConfig(
+            param_dict)
+
         self.gradient_clipping = get_gradient_clipping(param_dict)
         self.fp16_enabled = get_fp16_enabled(param_dict)
         self.loss_scale = get_loss_scale(param_dict)
@@ -285,6 +331,7 @@ class DeepSpeedConfig(object):
         self.scheduler_params = get_scheduler_params(param_dict)
 
         self.wall_clock_breakdown = get_wall_clock_breakdown(param_dict)
+        self.memory_breakdown = get_memory_breakdown(param_dict)
         self.tensorboard_enabled = get_tensorboard_enabled(param_dict)
         self.tensorboard_output_path = get_tensorboard_output_path(param_dict)
         self.tensorboard_job_name = get_tensorboard_job_name(param_dict)
@@ -305,8 +352,8 @@ class DeepSpeedConfig(object):
             f'Gradient accumulation steps: {grad_acc} has to be greater than 0'
 
         assert train_batch == micro_batch * grad_acc * self.world_size, \
-                (f'Check batch related parameters. Train_batch_size is not equal'
-                'to micro_batch_per_gpu * gradient_acc_step * world_size'
+                (f'Check batch related parameters. train_batch_size is not equal'
+                ' to micro_batch_per_gpu * gradient_acc_step * world_size'
                 f'{train_batch} != {micro_batch} * {grad_acc} * {self.world_size}')
 
     def _set_batch_related_parameters(self):
@@ -387,6 +434,7 @@ class DeepSpeedConfig(object):
     def _do_error_check(self):
         if self.zero_enabled:
             assert self.fp16_enabled, "DeepSpeedConfig: ZeRO is only supported if fp16 is enabled"
+            assert self.zero_optimization_stage <= MAX_STAGE_ZERO_OPTIMIZATION, "DeepSpeedConfig: Maximum supported ZeRO stage is {}".format(MAX_STAGE_ZERO_OPTIMIZATION)
 
         assert self.train_micro_batch_size_per_gpu, "DeepSpeedConfig: {} is not defined".format(TRAIN_MICRO_BATCH_SIZE_PER_GPU)
 

deepspeed/pt/deepspeed_config_utils.py

+"""
+Copyright (c) Microsoft Corporation
+Licensed under the MIT license.
+"""
+"""
+Collection of DeepSpeed configuration utilities
+"""
+
+
+def get_scalar_param(param_dict, param_name, param_default_value):
+    if param_name in param_dict.keys():
+        return param_dict[param_name]
+    else:
+        return param_default_value
+
+
+def dict_raise_error_on_duplicate_keys(ordered_pairs):
+    """Reject duplicate keys."""
+    d = {}
+    for k, v in ordered_pairs:
+        if k in d:
+            raise ValueError("Duplicate key in DeepSpeed config: %r" % (k, ))
+        else:
+            d[k] = v
+    return d

deepspeed/pt/deepspeed_constants.py

@@ -15,7 +15,7 @@ ROUTE_ENCODE = "encode"
 # Batch size
 #############################################
 TRAIN_BATCH_SIZE = "train_batch_size"
-TRAIN_BATCH_SIZE_DEFAULT = 1
+TRAIN_BATCH_SIZE_DEFAULT = None
 
 #############################################
 # Optimizer and lr scheduler
@@ -133,14 +133,27 @@ GRADIENT_CLIPPING_DEFAULT = 0.
 # ZeRO optimization
 #########################################
 # ZeRO optimization. By default, this optimization is not enabled.
-# Users can configure in ds_config.json as below example:
+# Users have to configure the desired optimization (0 means disabled) in params.json as below example:
 ZERO_FORMAT = '''
 ZeRO optimization should be enabled as:
-"zero_optimization": true,
-"zero_all_gather_size": 200
+"session_params": {
+  "zero_optimization": [0|1|2],
+  "zero_all_gather_size": 200
+}
 '''
+
 ZERO_OPTIMIZATION = 'zero_optimization'
-ZERO_OPTIMIZATION_DEFAULT = False
+ZERO_OPTIMIZATION_DEFAULT = 0
+ZERO_OPTIMIZATION_OPTIMIZER_STATES = 1
+ZERO_OPTIMIZATION_GRADIENTS = 2
+ZERO_OPTIMIZATION_WEIGHTS = 3
+MAX_STAGE_ZERO_OPTIMIZATION = ZERO_OPTIMIZATION_GRADIENTS
+
+ZERO_REDUCE_SCATTER = "zero_reduce_scatter"
+ZERO_REDUCE_SCATTER_DEFAULT = True
+
+ZERO_MAX_ELEMENTS_PER_COMM = "zero_max_elements_per_comm"
+ZERO_MAX_ELEMENTS_PER_COMM_DEFAULT = 5e8
 
 ALLGATHER_SIZE = 'allgather_size'
 ALLGATHER_SIZE_DEFAULT = 500000000
@@ -217,6 +230,9 @@ Wall block breakdown should be enabled as:
 WALL_CLOCK_BREAKDOWN = 'wall_clock_breakdown'
 WALL_CLOCK_BREAKDOWN_DEFAULT = False
 
+MEMORY_BREAKDOWN = 'memory_breakdown'
+MEMORY_BREAKDOWN_DEFAULT = False
+
 #########################################
 # Tensorboard
 #########################################

deepspeed/pt/deepspeed_light.py

@@ -8,11 +8,14 @@ import os
 import warnings
 import torch.distributed as dist
 from torch.nn.modules import Module
+from torch.distributed.distributed_c10d import _get_global_rank
 
 from tensorboardX import SummaryWriter
 
 from deepspeed.pt.deepspeed_timer import ThroughputTimer, SynchronizedWallClockTimer
 from deepspeed.pt.deepspeed_zero_optimizer import FP16_DeepSpeedZeroOptimizer
+from deepspeed.pt.zero_optimizer_stage1 import FP16_DeepSpeedZeroOptimizer_Stage1
+import deepspeed.pt.deepspeed_checkpointing as deepspeed_activation_checkpointing
 
 from deepspeed.pt.fp16_optimizer import FP16_Optimizer
 from deepspeed.pt.fp16_unfused_optimizer import FP16_UnfusedOptimizer
@@ -21,8 +24,10 @@ from deepspeed.pt.deepspeed_config import DeepSpeedConfig, \
     ADAM_OPTIMIZER, LAMB_OPTIMIZER, DEEPSPEED_OPTIMIZERS
 
 from deepspeed.pt.deepspeed_dataloader import DeepSpeedDataLoader
-from deepspeed.pt.deepspeed_constants import ROUTE_TRAIN, ROUTE_PREDICT, \
-    ROUTE_EVAL, TORCH_DISTRIBUTED_DEFAULT_PORT
+from deepspeed.pt.deepspeed_constants import \
+    ROUTE_TRAIN, ROUTE_PREDICT, ROUTE_EVAL, \
+    TORCH_DISTRIBUTED_DEFAULT_PORT, \
+    ZERO_OPTIMIZATION_OPTIMIZER_STATES, ZERO_OPTIMIZATION_GRADIENTS
 
 import deepspeed.pt.deepspeed_lr_schedules as lr_schedules
 from deepspeed.pt.deepspeed_csr_tensor import CSRTensor
@@ -96,7 +101,8 @@ class DeepSpeedLight(Module):
                  lr_scheduler=None,
                  mpu=None,
                  dist_init_required=None,
-                 collate_fn=None):
+                 collate_fn=None,
+                 config_params=None):
         super(DeepSpeedLight, self).__init__()
 
         logging.basicConfig(level=logging.INFO,
@@ -116,6 +122,7 @@ class DeepSpeedLight(Module):
         self.gradient_predivide_factor = 1.0
         self.gradient_average = True
         self.warn_unscaled_loss = True
+        self.config_params = config_params
 
         if dist_init_required is None:
             dist_init_required = not dist.is_initialized()
@@ -146,6 +153,9 @@ class DeepSpeedLight(Module):
         # Configure distributed model
         self._configure_distributed_model(model)
 
+        # Configure wall clock timer
+        self.timers = SynchronizedWallClockTimer()
+
         # Throughput timer
         self.tput_timer = ThroughputTimer(
             batch_size=self.train_micro_batch_size_per_gpu(),
@@ -163,9 +173,6 @@ class DeepSpeedLight(Module):
             self._configure_lr_scheduler(lr_scheduler)
             self._report_progress(0)
 
-        # Configure wall clock timer
-        self.timers = SynchronizedWallClockTimer()
-
         # Bookkeeping for csr support
         self.csr_tensor_module_names = set()
         if self.sparse_gradients_enabled():
@@ -245,6 +252,9 @@ class DeepSpeedLight(Module):
     def wall_clock_breakdown(self):
         return self._config.wall_clock_breakdown
 
+    def memory_breakdown(self):
+        return self._config.memory_breakdown
+
     def sparse_gradients_enabled(self):
         return self._config.sparse_gradients_enabled
 
@@ -275,6 +285,30 @@ class DeepSpeedLight(Module):
     def zero_allow_untested_optimizer(self):
         return self._config.zero_allow_untested_optimizer
 
+    def zero_reduce_scatter(self):
+        return self._config.zero_config.reduce_scatter
+
+    def zero_overlap_comm(self):
+        return self._config.zero_config.overlap_comm
+
+    def zero_max_elements_per_comm(self):
+        return self._config.zero_max_elements_per_comm
+
+    def zero_optimization_stage(self):
+        return self._config.zero_optimization_stage
+
+    def zero_reduce_bucket_size(self):
+        return self._config.zero_config.reduce_bucket_size
+
+    def zero_allgather_bucket_size(self):
+        return self._config.zero_config.allgather_bucket_size
+
+    def zero_optimization_partition_gradients(self):
+        return self.zero_optimization_stage() >= ZERO_OPTIMIZATION_GRADIENTS
+
+    def zero_contiguous_gradients(self):
+        return self._config.zero_config.contiguous_gradients
+
     def allgather_size(self):
         return self._config.allgather_size
 
@@ -296,8 +330,8 @@ class DeepSpeedLight(Module):
     def steps_per_print(self):
         return self._config.steps_per_print
 
-    def disable_allgather(self):
-        return self._config.disable_allgather
+    def zero_allgather_partitions(self):
+        return self._config.zero_config.allgather_partitions
 
     def dump_state(self):
         return self._config.dump_state
@@ -375,7 +409,9 @@ class DeepSpeedLight(Module):
     # Configure based on command line arguments
     def _configure_with_arguments(self, args, mpu):
         self.local_rank = args.local_rank if hasattr(args, 'local_rank') else 0
-        self._config = DeepSpeedConfig(args.deepspeed_config, mpu)
+        self._config = DeepSpeedConfig(args.deepspeed_config,
+                                       mpu,
+                                       param_dict=self.config_params)
 
     # Validate command line arguments
     def _do_args_sanity_check(self, args):
@@ -390,6 +426,7 @@ class DeepSpeedLight(Module):
         assert hasattr(args, 'local_rank') and type(args.local_rank) == int, \
             'DeepSpeed requires integer command line parameter --local_rank'
 
+        if self.config_params is None:
             assert hasattr(args, 'deepspeed_config') and args.deepspeed_config is not None, \
                 'DeepSpeed requires --deepspeed_config to specify configuration file'
 
@@ -424,7 +461,8 @@ class DeepSpeedLight(Module):
         else:
             self.data_parallel_group = self.mpu.get_data_parallel_group()
             self.dp_world_size = self.mpu.get_data_parallel_world_size()
-            src_rank = self.mpu.get_model_parallel_rank()
+            src_rank = _get_global_rank(self.mpu.get_data_parallel_group(), 0)
+            print(f"global src_rank={src_rank}")
         for p in self.module.parameters():
             if torch.is_tensor(p):
                 dist.broadcast(p, src_rank, group=self.data_parallel_group)
@@ -518,17 +556,42 @@ class DeepSpeedLight(Module):
         return optimizer
 
     def _configure_zero_optimizer(self, optimizer):
-        logging.info('Creating fp16 zero optimizer')
-        optimizer = FP16_DeepSpeedZeroOptimizer(
+        zero_stage = self.zero_optimization_stage()
+        logging.info('Creating fp16 ZeRO stage {} optimizer'.format(zero_stage))
+
+        if zero_stage == ZERO_OPTIMIZATION_OPTIMIZER_STATES:
+            assert self.zero_reduce_scatter(), 'Stage 1 only supports reduce scatter mode'
+            logging.info('Creating fp16 ZeRO Optimizer Stage 1')
+            optimizer = FP16_DeepSpeedZeroOptimizer_Stage1(
                 optimizer,
                 static_loss_scale=self.loss_scale(),
                 dynamic_loss_scale=self.dynamic_loss_scale(),
                 dynamic_loss_args=self.dynamic_loss_scale_args(),
+                clip_grad=self.gradient_clipping(),
+                all_gather_partitions=self.zero_allgather_partitions(),
+                allgather_size=self.zero_allgather_bucket_size(),
+                max_elements_per_comm=self.zero_reduce_bucket_size(),
                 dp_process_group=self.data_parallel_group,
+                mpu=self.mpu)
+        elif zero_stage == ZERO_OPTIMIZATION_GRADIENTS:
+            assert self.gradient_accumulation_steps() == 1, "ZeRO stage 2 does not support gradient accumulation, if you need gradient accumulation please use stage 1"
+            optimizer = FP16_DeepSpeedZeroOptimizer(
+                optimizer,
+                timers=self.timers,
+                static_loss_scale=self.loss_scale(),
+                dynamic_loss_scale=self.dynamic_loss_scale(),
+                dynamic_loss_args=self.dynamic_loss_scale_args(),
                 clip_grad=self.gradient_clipping(),
-            all_gather_partitions=not self.disable_allgather(),
-            allgather_size=self.allgather_size(),
+                contiguous_gradients=self.zero_contiguous_gradients(),
+                reduce_bucket_size=self.zero_reduce_bucket_size(),
+                allgather_bucket_size=self.zero_allgather_bucket_size(),
+                dp_process_group=self.data_parallel_group,
+                reduce_scatter=self.zero_reduce_scatter(),
+                overlap_comm=self.zero_overlap_comm(),
                 mpu=self.mpu)
+        else:
+            raise NotImplementedError("ZeRO stage {} not implemented".format(zero_stage))
+        logging.info('Creating fp16 zero stage {} optimizer'.format(zero_stage))
 
         return optimizer
 
@@ -624,6 +687,15 @@ class DeepSpeedLight(Module):
 
     def allreduce_gradients(self, bucket_size=MEMORY_OPT_ALLREDUCE_SIZE):
         if self.is_gradient_accumulation_boundary():
+            if self.zero_optimization_stage() == ZERO_OPTIMIZATION_OPTIMIZER_STATES:
+                assert self.zero_reduce_scatter()
+                self.optimizer.reduce_scatter_gradients(
+                    postscale_gradients=self.postscale_gradients(),
+                    gradient_predivide_factor=self.gradient_predivide_factor,
+                    gradient_average=self.gradient_average)
+            elif self.zero_optimization_partition_gradients():
+                self.optimizer.overlapping_partition_gradients_reduce_epilogue()
+            else:
                 self.buffered_allreduce_fallback(elements_per_buffer=bucket_size)
 
     def backward(self, loss, allreduce_gradients=True):
@@ -636,7 +708,7 @@ class DeepSpeedLight(Module):
 
         # scale loss w.r.t. gradient accumulation if needed
         if self.gradient_accumulation_steps() > 1:
-            loss = self._scale_loss(loss)
+            loss = self._scale_loss(loss.float())
 
         # Log training Loss
         if self.tensorboard_enabled():
@@ -765,16 +837,17 @@ class DeepSpeedLight(Module):
                 'backward_inner_microstep',
                 'backward_allreduce_microstep',
                 'step_microstep'
-            ])
-            # Log timing
-            if self.tensorboard_enabled():
+            ],
+                            memory_breakdown=self.memory_breakdown())
+
             if self.is_gradient_accumulation_boundary():
-                    if self.global_rank == 0:
-                        self.summary_events = [(f'Train/Samples/elapsed_time_ms_forward', self.timers('forward').elapsed(reset=False) * 1000.0, self.sample_count), \
-                                                (f'Train/Samples/elapsed_time_ms_backward', self.timers('backward').elapsed(reset=False) * 1000.0, self.sample_count), \
-                                                (f'Train/Samples/elapsed_time_ms_backward_inner', self.timers('backward_inner').elapsed(reset=False) * 1000.0, self.sample_count), \
-                                                (f'Train/Samples/elapsed_time_ms_backward_allreduce', self.timers('backward_allreduce').elapsed(reset=False) * 1000.0, self.sample_count), \
-                                                (f'Train/Samples/elapsed_time_ms_step', self.timers('step').elapsed(reset=False) * 1000.0, self.sample_count)
+                if self.tensorboard_enabled() and torch.distributed.get_rank(
+                ) == 0:  # this is done before the log because log resets timers
+                    self.summary_events = [(f'Train/elapsed_time_ms_forward', self.timers('forward').elapsed(reset=False) * 1000.0, self.sample_count), \
+                                            (f'Train/elapsed_time_ms_backward', self.timers('backward').elapsed(reset=False) * 1000.0, self.sample_count), \
+                                            (f'Train/elapsed_time_ms_backward_inner', self.timers('backward_inner').elapsed(reset=False) * 1000.0, self.sample_count), \
+                                            (f'Train/elapsed_time_ms_backward_allreduce', self.timers('backward_allreduce').elapsed(reset=False) * 1000.0, self.sample_count), \
+                                            (f'Train/elapsed_time_ms_step', self.timers('step').elapsed(reset=False) * 1000.0, self.sample_count)
                                             ]
                     for event in self.summary_events:  # write_summary_events
                         self.summary_writer.add_scalar(event[0], event[1], event[2])
@@ -971,19 +1044,30 @@ class DeepSpeedLight(Module):
         if not os.path.exists(dirname):
             os.makedirs(dirname)
 
-    def load_checkpoint(self, load_dir, tag, load_optimizer_states=True):
+    def load_checkpoint(self,
+                        load_dir,
+                        tag,
+                        load_module_strict=True,
+                        load_optimizer_states=True,
+                        load_lr_scheduler_states=True):
         r"""Load training checkpoint
 
         Arguments:
             load_dir: Required. Directory to load the checkpoint from
             tag: Required. Checkpoint tag used as a unique identifier for the checkpoint. Ex. Global Step.
+            load_module_strict: Optional. Boolean to strictly enforce that the keys in state_dict of module and checkpoint match.
             load_optimizer_states: Optional. Boolean to load the training optimizer states from Checkpoint. Ex. ADAM's momentum and variance
+            load_lr_scheduler_states: Optional. Boolean to add the learning rate scheduler states from Checkpoint.
         Return:
             load_path: Path of the loaded checkpoint. None if loading the checkpoint failed
             client_state: State dictionary used for loading required training states in the client code.
         """
 
-        load_path, client_states = self._load_checkpoint(load_dir, tag, load_optimizer_states=load_optimizer_states)
+        load_path, client_states = self._load_checkpoint(load_dir,
+                                                         tag,
+                                                         load_module_strict=load_module_strict,
+                                                         load_optimizer_states=load_optimizer_states,
+                                                         load_lr_scheduler_states=load_lr_scheduler_states)
 
         if self.zero_optimization() and load_path is not None:
             self._load_zero_checkpoint(load_dir,
@@ -992,7 +1076,12 @@ class DeepSpeedLight(Module):
 
         return load_path, client_states
 
-    def _load_checkpoint(self, load_dir, tag, load_optimizer_states=True):
+    def _load_checkpoint(self,
+                         load_dir,
+                         tag,
+                         load_module_strict=True,
+                         load_optimizer_states=True,
+                         load_lr_scheduler_states=True):
 
         load_path = self._get_ckpt_name(load_dir, tag)
 
@@ -1005,12 +1094,13 @@ class DeepSpeedLight(Module):
         logging.info('Loading checkpoint: {}'.format(load_path))
         checkpoint = torch.load(load_path, map_location=lambda storage, loc: storage)
 
-        self.load_module_state_dict(checkpoint['module'])
+        self.load_module_state_dict(state_dict=checkpoint['module'],
+                                    strict=load_module_strict)
         if not self.zero_optimization():
             self.optimizer.load_state_dict(checkpoint['optimizer'],
                                            load_optimizer_states=load_optimizer_states)
 
-        if self.lr_scheduler is not None:
+        if load_lr_scheduler_states and self.lr_scheduler is not None:
             self.lr_scheduler.load_state_dict(checkpoint['lr_scheduler'])
 
         self.csr_tensor_module_names = checkpoint['csr_tensor_module_names']
@@ -1019,6 +1109,7 @@ class DeepSpeedLight(Module):
         deepspeed_states = [
             'module',
             'optimizer',
+            'lr_scheduler',
             'csr_tensor_module_names',
             'skipped_steps',
             'global_steps'
@@ -1058,19 +1149,15 @@ class DeepSpeedLight(Module):
         #There seems to be issue creating them in parallel
         self._create_checkpoint_files(save_dir, tag)
 
-        try:
         if self.save_non_zero_checkpoint:
             self._save_checkpoint(save_dir, tag, client_state=client_state)
 
         if self.save_zero_checkpoint:
             self._save_zero_checkpoint(save_dir, tag)
-        except:
-            logging.error(f'Failed Saving model checkpoint to {save_dir} with tag {tag}')
-            return False
+
         return True
 
     def _create_checkpoint_files(self, save_dir, tag):
-
         #checkpoint files are created sequentially
         for rank in range(self.world_size):
             if rank == self.global_rank:
@@ -1114,14 +1201,8 @@ class DeepSpeedLight(Module):
         torch.save(state, save_path)
 
     def _save_zero_checkpoint(self, save_path, tag):
-        try:
         zero_checkpoint_name = self._get_zero_ckpt_name(save_path, tag)
         #self._ensure_directory_exists(zero_checkpoint_name)
-
-        except:
-            logging.error(
-                f'Failed Saving Zero model checkpoint to {save_path} with tag {tag}')
-
         zero_sd = {'optimizer_state_dict': self.optimizer.state_dict()}
         torch.save(zero_sd, zero_checkpoint_name)
         logging.info('zero checkpoint saved {}'.format(zero_checkpoint_name))

deepspeed/pt/deepspeed_timer.py

@@ -69,13 +69,27 @@ class SynchronizedWallClockTimer:
             self.timers[name] = self.Timer(name)
         return self.timers[name]
 
-    def log(self, names, normalizer=1.0, reset=True):
+    @staticmethod
+    def memory_usage():
+        alloc = "mem_allocated: {:.4f} GB".format(torch.cuda.memory_allocated() /
+                                                  (1024 * 1024 * 1024))
+        max_alloc = "max_mem_allocated: {:.4f} GB".format(
+            torch.cuda.max_memory_allocated() / (1024 * 1024 * 1024))
+        cache = "cache_allocated: {:.4f} GB".format(torch.cuda.memory_cached() /
+                                                    (1024 * 1024 * 1024))
+        max_cache = "max_cache_allocated: {:.4f} GB".format(
+            torch.cuda.max_memory_cached() / (1024 * 1024 * 1024))
+        return " | {} | {} | {} | {}".format(alloc, max_alloc, cache, max_cache)
+
+    def log(self, names, normalizer=1.0, reset=True, memory_breakdown=False):
         """Log a group of timers."""
         assert normalizer > 0.0
         string = 'time (ms)'
         for name in names:
             elapsed_time = self.timers[name].elapsed(reset=reset) * 1000.0 / normalizer
             string += ' | {}: {:.2f}'.format(name, elapsed_time)
+        if memory_breakdown:
+            string += self.memory_usage()
         print_rank_0(string)
 
 

deepspeed/pt/deepspeed_utils.py

@@ -12,9 +12,10 @@ from torch._six import inf
 
 class CheckOverflow(object):
     '''Checks for overflow in gradient across parallel process'''
-    def __init__(self, param_groups=None, mpu=None):
+    def __init__(self, param_groups=None, mpu=None, zero_reduce_scatter=False):
         self.mpu = mpu
         self.params = [] if param_groups else None
+        self.zero_reduce_scatter = zero_reduce_scatter
         if param_groups:
             for group in param_groups:
                 for param in group:
@@ -54,8 +55,8 @@ class CheckOverflow(object):
 
     # `params` is a list / generator of torch.Variable
     def has_overflow_serial(self, params):
-        for p in params:
-            if p.grad is not None and self._has_inf_or_nan(p.grad.data):
+        for i, p in enumerate(params):
+            if p.grad is not None and self._has_inf_or_nan(p.grad.data, i):
                 return True
         return False
 
@@ -67,7 +68,11 @@ class CheckOverflow(object):
         #torch.distributed.all_reduce(overflow_gpu,
         #                             op=torch.distributed.ReduceOp.MAX,
         #                             group=mpu.get_model_parallel_group())
-        if self.mpu is not None:
+        if self.zero_reduce_scatter:
+            torch.distributed.all_reduce(overflow_gpu,
+                                         op=torch.distributed.ReduceOp.MAX,
+                                         group=torch.distributed.group.WORLD)
+        elif self.mpu is not None:
             torch.distributed.all_reduce(overflow_gpu,
                                          op=torch.distributed.ReduceOp.MAX,
                                          group=self.mpu.get_model_parallel_group())
@@ -76,7 +81,7 @@ class CheckOverflow(object):
 
     # `x` is a torch.Tensor
     @staticmethod
-    def _has_inf_or_nan(x):
+    def _has_inf_or_nan(x, i):
         try:
             # if x is half, the .float() incurs an additional deep copy, but it's necessary if
             # Pytorch's .sum() creates a one-element tensor of the same type as x
@@ -93,10 +98,25 @@ class CheckOverflow(object):
             return True
         else:
             if cpu_sum == float('inf') or cpu_sum == -float('inf') or cpu_sum != cpu_sum:
+                _handle_overflow(cpu_sum, x, i)
                 return True
             return False
 
 
+def _handle_overflow(cpu_sum, x, i):
+    import math
+    rank = torch.distributed.get_rank()
+    if rank == 0:
+        t_i = -1
+        for v_i, v in enumerate(x.data.contiguous().view(-1)):
+            if not math.isfinite(float(v)):
+                t_i = v_i
+                break
+        print(
+            f"rank {rank} detected overflow {cpu_sum} in tensor {i}:{t_i} shape {x.shape}"
+        )
+
+
 def get_grad_norm(parameters, norm_type=2, mpu=None):
     """Clips gradient norm of an iterable of parameters.
 
@@ -221,3 +241,33 @@ def get_weight_norm(parameters, norm_type=2, mpu=None):
         total_norm = -1
 
     return total_norm
+
+
+def is_model_parallel_parameter(p):
+    return hasattr(p, 'model_parallel') and p.model_parallel
+
+
+def see_memory_usage(message):
+    return
+    if torch.distributed.is_initialized() and not torch.distributed.get_rank() == 0:
+        return
+
+    # Print message except when distributed but not rank 0
+    print(message, flush=True)
+    print("Memory Allocated ",
+          torch.cuda.memory_allocated() / (1024 * 1024 * 1024),
+          "GigaBytes",
+          flush=True)
+    print("Max Memory Allocated ",
+          torch.cuda.max_memory_allocated() / (1024 * 1024 * 1024),
+          "GigaBytes",
+          flush=True)
+    print("Cache Allocated ",
+          torch.cuda.memory_cached() / (1024 * 1024 * 1024),
+          "GigaBytes",
+          flush=True)
+    print("Max cache Allocated ",
+          torch.cuda.max_memory_cached() / (1024 * 1024 * 1024),
+          "GigaBytes",
+          flush=True)
+    print(" ", flush=True)

deepspeed/pt/deepspeed_zero_config.py

+"""
+Copyright (c) Microsoft Corporation
+Licensed under the MIT license.
+"""
+
+import logging
+#from deepspeed.pt.deepspeed_constants import *
+from deepspeed.pt.deepspeed_config_utils import get_scalar_param
+
+#########################################
+# ZeRO optimization
+#########################################
+# ZeRO optimization. By default, this optimization is not enabled.
+# Users have to configure the desired optimization (0 means disabled) in params.json as below example:
+ZERO_FORMAT = '''
+ZeRO optimization should be enabled as:
+"session_params": {
+  "zero_optimization": {
+    "stage": [0|1|2],
+    "allgather_partitions": [true|false],
+    "allgather_bucket_size": 500000000,
+    "reduce_scatter": [true|false],
+    "contiguous_gradients" : [true|false]
+    "overlap_comm": [true|false],
+    "reduce_bucket_size": 500000000
+    }
+}
+'''
+
+ZERO_OPTIMIZATION = 'zero_optimization'
+ZERO_OPTIMIZATION_DISABLED = 0
+ZERO_OPTIMIZATION_OPTIMIZER_STATES = 1
+ZERO_OPTIMIZATION_GRADIENTS = 2
+ZERO_OPTIMIZATION_WEIGHTS = 3
+MAX_STAGE_ZERO_OPTIMIZATION = ZERO_OPTIMIZATION_GRADIENTS
+
+ZERO_OPTIMIZATION_STAGE = 'stage'
+ZERO_OPTIMIZATION_STAGE_1 = 'stage_1'
+ZERO_OPTIMIZATION_STAGE_2 = 'stage_2'
+ZERO_OPTIMIZATION_STAGE_3 = 'stage_3'
+
+ZERO_OPTIMIZATION_STAGE_DEFAULT = ZERO_OPTIMIZATION_DISABLED
+
+ZERO_OPTIMIZATION_ALLGATHER_PARTITIONS = 'allgather_partitions'
+ZERO_OPTIMIZATION_ALLGATHER_PARTITIONS_DEFAULT = True
+
+ZERO_OPTIMIZATION_REDUCE_SCATTER = 'reduce_scatter'
+ZERO_OPTIMIZATION_REDUCE_SCATTER_DEFAULT = True
+
+ZERO_OPTIMIZATION_OVERLAP_COMM = 'overlap_comm'
+ZERO_OPTIMIZATION_OVERLAP_COMM_DEFAULT = False
+
+ZERO_OPTIMIZATION_CONTIGUOUS_GRADIENTS = 'contiguous_gradients'
+ZERO_OPTIMIZATION_CONTIGUOUS_GRADIENTS_DEFAULT = True
+
+ZERO_OPTIMIZATION_REDUCE_BUCKET_SIZE = 'reduce_bucket_size'
+ZERO_OPTIMIZATION_REDUCE_BUCKET_SIZE_DEFAULT = 500000000
+
+ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE = 'allgather_bucket_size'
+ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE_DEFAULT = 500000000
+ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE_DEPRECATED = 'allgather_size'
+
+ZERO_OPTIMIZATION_DEFAULT = {
+    ZERO_OPTIMIZATION_STAGE: ZERO_OPTIMIZATION_STAGE_DEFAULT,
+    ZERO_OPTIMIZATION_CONTIGUOUS_GRADIENTS:
+    ZERO_OPTIMIZATION_CONTIGUOUS_GRADIENTS_DEFAULT,
+    ZERO_OPTIMIZATION_REDUCE_SCATTER: ZERO_OPTIMIZATION_REDUCE_SCATTER_DEFAULT,
+    ZERO_OPTIMIZATION_REDUCE_BUCKET_SIZE: ZERO_OPTIMIZATION_REDUCE_BUCKET_SIZE_DEFAULT,
+    ZERO_OPTIMIZATION_ALLGATHER_PARTITIONS:
+    ZERO_OPTIMIZATION_ALLGATHER_PARTITIONS_DEFAULT,
+    ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE:
+    ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE_DEFAULT
+}
+
+
+class DeepSpeedZeroConfig(object):
+    def __init__(self, param_dict):
+        super(DeepSpeedZeroConfig, self).__init__()
+
+        self.stage = None
+        self.contiguous_gradients = None
+        self.reduce_scatter = None
+        self.reduce_bucket_size = None
+        self.allgather_partitions = None
+        self.allgather_bucket_size = None
+        self.overlap_comm = None
+
+        if ZERO_OPTIMIZATION in param_dict.keys():
+            zero_config_dict = param_dict[ZERO_OPTIMIZATION]
+            if type(zero_config_dict) is bool:
+                zero_config_dict = self.read_zero_config_deprecated(param_dict)
+        else:
+            zero_config_dict = ZERO_OPTIMIZATION_DEFAULT
+
+        self._initialize(zero_config_dict)
+
+    def read_zero_config_deprecated(self, param_dict):
+        zero_config_dict = {}
+        zero_config_dict[
+            ZERO_OPTIMIZATION_STAGE] = 1 if param_dict[ZERO_OPTIMIZATION] else 0
+        if zero_config_dict[ZERO_OPTIMIZATION_STAGE] > 0:
+            zero_config_dict[ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE] = get_scalar_param(
+                param_dict,
+                ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE_DEPRECATED,
+                ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE_DEFAULT)
+
+        logging.warning(
+            'DeepSpeedConfig: this format of ZeRO optimization setup is deprecated. Please use the following format: {}'
+            .format(ZERO_FORMAT))
+        return zero_config_dict
+
+    """
+    For json serialization
+    """
+
+    def repr(self):
+        return self.__dict__
+
+    def _initialize(self, zero_config_dict):
+        self.stage = get_scalar_param(zero_config_dict,
+                                      ZERO_OPTIMIZATION_STAGE,
+                                      ZERO_OPTIMIZATION_STAGE_DEFAULT)
+
+        self.contiguous_gradients = get_scalar_param(
+            zero_config_dict,
+            ZERO_OPTIMIZATION_CONTIGUOUS_GRADIENTS,
+            ZERO_OPTIMIZATION_CONTIGUOUS_GRADIENTS_DEFAULT)
+
+        self.reduce_bucket_size = get_scalar_param(
+            zero_config_dict,
+            ZERO_OPTIMIZATION_REDUCE_BUCKET_SIZE,
+            ZERO_OPTIMIZATION_REDUCE_BUCKET_SIZE_DEFAULT)
+
+        self.reduce_scatter = get_scalar_param(zero_config_dict,
+                                               ZERO_OPTIMIZATION_REDUCE_SCATTER,
+                                               ZERO_OPTIMIZATION_REDUCE_SCATTER_DEFAULT)
+
+        self.overlap_comm = get_scalar_param(zero_config_dict,
+                                             ZERO_OPTIMIZATION_OVERLAP_COMM,
+                                             ZERO_OPTIMIZATION_OVERLAP_COMM_DEFAULT)
+
+        self.allgather_partitions = get_scalar_param(
+            zero_config_dict,
+            ZERO_OPTIMIZATION_ALLGATHER_PARTITIONS,
+            ZERO_OPTIMIZATION_ALLGATHER_PARTITIONS_DEFAULT)
+
+        self.allgather_bucket_size = get_scalar_param(
+            zero_config_dict,
+            ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE,
+            ZERO_OPTIMIZATION_ALLGATHER_BUCKET_SIZE_DEFAULT)

deepspeed/pt/zero_utils.py

+import torch
+import torch.distributed as dist
+
+
+def _initialize_parameter_parallel_groups(parameter_parallel_size=None):
+    data_parallel_size = int(dist.get_world_size())
+    if parameter_parallel_size is None:
+        parameter_parallel_size = int(data_parallel_size)
+    print(data_parallel_size, parameter_parallel_size)
+    assert data_parallel_size % parameter_parallel_size == 0, \
+        'world size should be divisible by parameter parallel size'
+    rank = dist.get_rank()
+    my_group = None
+    for i in range(dist.get_world_size() // parameter_parallel_size):
+        ranks = range(i * parameter_parallel_size, (i + 1) * parameter_parallel_size)
+        group = torch.distributed.new_group(ranks)
+        if rank in ranks:
+            my_group = group
+    return my_group
+
+
+def pprint(msg):
+    if not dist.is_initialized() or dist.get_rank() == 0:
+        print(msg)

docs/_config.yml

@@ -29,6 +29,14 @@ collections:
   tutorials:
     output: true
     permalink: /:collection/:path/
+    order:
+      - getting-started.md
+      - azure.md
+      - cifar-10.md
+      - bert-pretraining.md
+      - megatron.md
+      - 1Cycle.md
+      - lrrt.md
 
 defaults:
   - scope:

docs/_data/navigation.yml

@@ -18,7 +18,7 @@ lnav:
     children:
       - title: "Installation"
         url: /getting-started/#installation
-      - title: "Writing Models"
+      - title: "Writing models"
         url: /getting-started/#writing-deepspeed-models
       - title: "Training"
         url: /getting-started/#training
@@ -37,19 +37,25 @@ lnav:
         url: /docs/config-json/#communication-options
       - title: "FP16"
         url: /docs/config-json/#fp16-training-options
+      - title: "ZeRO optimizations"
+        url: /docs/config-json/#zero-optimizations-for-fp16-training
       - title: "Logging"
         url: /docs/config-json/#logging
+      - title: "Activation checkpointing"
+        url: /docs/config-json/#activation-checkpointing
   - title: "Tutorials"
     url: /tutorials/
     children:
-      - title: "Getting Started on Azure"
+      - title: "Getting started"
+        url: /getting-started/
+      - title: "Getting started on Azure"
         url: /tutorials/azure/
       - title: "CIFAR-10"
         url: /tutorials/cifar-10/
-      - title: "Megatron-LM GPT2"
-        url: /tutorials/megatron/
       - title: "BERT Pre-training"
         url: /tutorials/bert-pretraining/
+      - title: "Megatron-LM GPT2"
+        url: /tutorials/megatron/
       - title: "1-Cycle Schedule"
         url: /tutorials/1Cycle/
       - title: "Learning Rate Range Test"

docs/_layouts/news-home.html

@@ -12,12 +12,6 @@ layout: archive
 {% endif %}
 
 
-<h2>Features Coming Soon</h2>
-{% assign soon = posts | where: "sneak_preview", "true" %}
-{% for post in soon %}
-  {% include archive-single.html %}
-{% endfor %}
-
 <h2>{{ site.data.ui-text[site.locale].recent_posts | default: "Recent Posts" }}</h2>
 {% assign news = posts | where: "sneak_preview", "false" %}
 {% for post in news %}