                       help='End of run weight decay coefficient for L2 regularization.')
    group.add_argument('--weight-decay-incr-style', type=str, default='constant',
                       choices=['constant', 'linear', 'cosine'],
                       help='Weight decay increment function.')
    group.add_argument('--clip-grad', type=float, default=1.0,
                       help='Gradient clipping based on global L2 norm.')
    group.add_argument('--adam-beta1', type=float, default=0.9,
                       help='First coefficient for computing running averages '
                       'of gradient and its square')
    group.add_argument('--adam-beta2', type=float, default=0.999,
                       help='Second coefficient for computing running averages '
                       'of gradient and its square')
    group.add_argument('--adam-eps', type=float, default=1e-08,
                       help='Term added to the denominator to improve'
                       'numerical stability')
    group.add_argument('--sgd-momentum', type=float, default=0.9,
                       help='Momentum factor for sgd')
    return parser

def _add_training_args(parser):
    group = parser.add_argument_group(title='training')

    group.add_argument('--micro-batch-size', type=int, default=1,
                       help='Batch size per model instance (local batch size). '
                       'Global batch size is local batch size times data '
                       'parallel size times number of micro batches.')
    group.add_argument('--batch-size', type=int, default=None,
                       help='Old batch size parameter, do not use. '
                       'Use --micro-batch-size instead')
    group.add_argument('--global-batch-size', type=int, default=None,
                       help='Training batch size. If set, it should be a '
                       'multiple of micro-batch-size times data-parallel-size. '
                       'If this value is None, then '
                       'use micro-batch-size * data-parallel-size as the '
                       'global batch size. This choice will result in 1 for '
                       'number of micro-batches.')
    group.add_argument('--rampup-batch-size', nargs='*', default=None,
                       help='Batch size ramp up with the following values:'
                       '  --rampup-batch-size <start batch size> '
                       '                      <batch size incerement> '
                       '                      <ramp-up samples> '
                       'For example:'
                       '   --rampup-batch-size 16 8 300000 \ '
                       '   --global-batch-size 1024'
                       'will start with global batch size 16 and over '
                       ' (1024 - 16) / 8 = 126 intervals will increase'
                       'the batch size linearly to 1024. In each interval'
                       'we will use approximately 300000 / 126 = 2380 samples.')
    group.add_argument('--recompute-activations', action='store_true',
                       help='recompute activation to allow for training '
                       'with larger models, sequences, and batch sizes.')
    group.add_argument('--recompute-granularity', type=str, default=None,
                       choices=['full', 'selective'],
                       help='Checkpoint activations to allow for training '
                       'with larger models, sequences, and batch sizes. '
                       'It is supported at two granularities 1) full: '
                       'whole transformer layer is recomputed, '
                       '2) selective: core attention part of the transformer '
                       'layer is recomputed.')
    group.add_argument('--no-check-for-nan-in-loss-and-grad', action='store_false',
                       help='Check for NaNs in loss and grad',
                       dest='check_for_nan_in_loss_and_grad')
    group.add_argument('--distribute-saved-activations',
                       action='store_true',
                       help='If set, distribute recomputed activations '
                       'across model parallel group.')
    group.add_argument('--recompute-method', type=str, default=None,
                       choices=['uniform', 'block'],
                       help='1) uniform: uniformly divide the total number of '
                       'Transformer layers and recompute the input activation of '
                       'each divided chunk at specified granularity, '
                       '2) recompute the input activations of only a set number of '
                       'individual Transformer layers per pipeline stage and do the '
                       'rest without any recomputing at specified granularity'
                       'default) do not apply activations recompute to any layers')
    group.add_argument('--recompute-num-layers', type=int, default=None,
                       help='1) uniform: the number of Transformer layers in each '
                       'uniformly divided recompute unit, '
                       '2) block: the number of individual Transformer layers '
                       'to recompute within each pipeline stage.')
    group.add_argument('--profile', action='store_true',
                       help='Enable nsys profiling. When using this option, nsys '
                       'options should be specified in commandline. An example '
                       'nsys commandline is `nsys profile -s none -t nvtx,cuda '
                       '-o <path/to/output_file> --force-overwrite true '
                       '--capture-range=cudaProfilerApi '
                       '--capture-range-end=stop`.')
    group.add_argument('--profile-step-start', type=int, default=10,
                       help='Gloable step to start profiling.')
    group.add_argument('--profile-step-end', type=int, default=12,
                       help='Gloable step to stop profiling.')
    group.add_argument('--profile-ranks', nargs='+', type=int, default=[0],
                       help='Global ranks to profile.')

    # deprecated
    group.add_argument('--checkpoint-activations', action='store_true',
                       help='Checkpoint activation to allow for training '
                       'with larger models, sequences, and batch sizes.')
    group.add_argument('--train-iters', type=int, default=None,
                       help='Total number of iterations to train over all '
                       'training runs. Note that either train-iters or '
                       'train-samples should be provided.')
    group.add_argument('--train-samples', type=int, default=None,
                       help='Total number of samples to train over all '
                       'training runs. Note that either train-iters or '
                       'train-samples should be provided.')
    group.add_argument('--log-interval', type=int, default=100,
                       help='Report loss and timing interval.')
    group.add_argument('--exit-interval', type=int, default=None,
                       help='Exit the program after the iteration is divisible '
                       'by this value.')
    group.add_argument('--exit-duration-in-mins', type=int, default=None,
                       help='Exit the program after this many minutes.')
    group.add_argument('--exit-signal-handler', action='store_true',
                       help='Dynamically save the checkpoint and shutdown the '
                       'training if SIGTERM is received')
    group.add_argument('--tensorboard-dir', type=str, default=None,
                       help='Write TensorBoard logs to this directory.')
    group.add_argument('--no-masked-softmax-fusion',
                       action='store_false',
                       help='Disable fusion of query_key_value scaling, '
                       'masking, and softmax.',
                       dest='masked_softmax_fusion')
    group.add_argument('--no-bias-gelu-fusion', action='store_false',
                       help='Disable bias and gelu fusion.',
                       dest='bias_gelu_fusion')
    group.add_argument('--no-bias-dropout-fusion', action='store_false',
                       help='Disable bias and dropout fusion.',
                       dest='bias_dropout_fusion')
    group.add_argument('--use-flash-attn', action='store_true',
                       help='use FlashAttention implementation of attention. '
                       'https://arxiv.org/abs/2205.14135')
    group.add_argument('--disable-bias-linear', action='store_false',
                       help='Disable bias in the linear layers',
                       dest='add_bias_linear')
    group.add_argument('--optimizer', type=str, default='adam',
                       choices=['adam', 'sgd'],
                       help='Optimizer function')
    group.add_argument('--dataloader-type', type=str, default=None,
                       choices=['single', 'cyclic'],
                       help='Single pass vs multiple pass data loader')
    group.add_argument('--no-async-tensor-model-parallel-allreduce',
                       action='store_false',
                       help='Disable asynchronous execution of '
                       'tensor-model-parallel all-reduce with weight '
                       'gradient compuation of a column-linear layer.',
                       dest='async_tensor_model_parallel_allreduce')
    group.add_argument('--no-persist-layer-norm', action='store_true',
                       help='Disable using persistent fused layer norm kernel. '
                       'This kernel supports only a set of hidden sizes. Please '
                       'check persist_ln_hidden_sizes if your hidden '
                       'size is supported.')
    group.add_argument('--sequence-parallel', action='store_true',
                       help='Enable sequence parallel optimization.')
    group.add_argument('--no-gradient-accumulation-fusion',
                       action='store_false',
                       help='Disable fusing gradient accumulation to weight '
                       'gradient computation of linear layers',
                       dest='gradient_accumulation_fusion')
    group.add_argument('--use-mcore-models', action='store_true',
                       help='Use the implementation from megatron core',
                       dest='use_mcore_models')
    group.add_argument('--expert-parallel', action='store_true',
                       help='Enable expert parallel optimization.')

    return parser

def _add_initialization_args(parser):
    group = parser.add_argument_group(title='initialization')

    group.add_argument('--seed', type=int, default=1234,
                       help='Random seed used for python, numpy, '
                       'pytorch, and cuda.')
    group.add_argument('--data-parallel-random-init', action='store_true',
                       help='Enable random initialization of params '
                       'across data parallel ranks')
    group.add_argument('--init-method-std', type=float, default=0.02,
                       help='Standard deviation of the zero mean normal '
                       'distribution used for weight initialization.')
    group.add_argument('--init-method-xavier-uniform', action='store_true',
                       help='Enable Xavier uniform parameter initialization')

    return parser


                       help='Disable using persistent fused layer norm kernel. '
                       'This kernel supports only a set of hidden sizes. Please '
                       'check persist_ln_hidden_sizes if your hidden '
                       'size is supported.')
    group.add_argument('--sequence-parallel', action='store_true',
                       help='Enable sequence parallel optimization.')
    group.add_argument('--no-gradient-accumulation-fusion',
                       action='store_false',
                       help='Disable fusing gradient accumulation to weight '
                       'gradient computation of linear layers',
                       dest='gradient_accumulation_fusion')
    group.add_argument('--use-mcore-models', action='store_true',
                       help='Use the implementation from megatron core',
                       dest='use_mcore_models')
    group.add_argument('--expert-parallel', action='store_true',
                       help='Enable expert parallel optimization.')

    return parser

def _add_initialization_args(parser):
    group = parser.add_argument_group(title='initialization')

    group.add_argument('--seed', type=int, default=1234,
                       help='Random seed used for python, numpy, '
                       'pytorch, and cuda.')
    group.add_argument('--data-parallel-random-init', action='store_true',
                       help='Enable random initialization of params '
                       'across data parallel ranks')
    group.add_argument('--init-method-std', type=float, default=0.02,
                       help='Standard deviation of the zero mean normal '
                       'distribution used for weight initialization.')
    group.add_argument('--init-method-xavier-uniform', action='store_true',
                       help='Enable Xavier uniform parameter initialization')

    return parser

def _add_learning_rate_args(parser):
    group = parser.add_argument_group(title='learning rate')

    group.add_argument('--lr', type=float, default=None,
                       help='Initial learning rate. Depending on decay style '
                       'and initial warmup, the learing rate at each '
                       'iteration would be different.')
    group.add_argument('--lr-decay-style', type=str, default='linear',
                       choices=['constant', 'linear', 'cosine', 'inverse-square-root'],
                       help='Learning rate decay function.')
    group.add_argument('--lr-decay-iters', type=int, default=None,
                       help='number of iterations to decay learning rate over,'
                       ' If None defaults to `--train-iters`')
    group.add_argument('--lr-decay-samples', type=int, default=None,
                       help='number of samples to decay learning rate over,'
                       ' If None defaults to `--train-samples`')
    group.add_argument('--lr-warmup-fraction', type=float, default=None,
                       help='fraction of lr-warmup-(iters/samples) to use '


def _add_initialization_args(parser):
    group = parser.add_argument_group(title='initialization')

    group.add_argument('--seed', type=int, default=1234,
                       help='Random seed used for python, numpy, '
                       'pytorch, and cuda.')
    group.add_argument('--data-parallel-random-init', action='store_true',
                       help='Enable random initialization of params '
                       'across data parallel ranks')
    group.add_argument('--init-method-std', type=float, default=0.02,
                       help='Standard deviation of the zero mean normal '
                       'distribution used for weight initialization.')
    group.add_argument('--init-method-xavier-uniform', action='store_true',
                       help='Enable Xavier uniform parameter initialization')

    return parser

def _add_learning_rate_args(parser):
    group = parser.add_argument_group(title='learning rate')

    group.add_argument('--lr', type=float, default=None,
                       help='Initial learning rate. Depending on decay style '
                       'and initial warmup, the learing rate at each '
                       'iteration would be different.')
    group.add_argument('--lr-decay-style', type=str, default='linear',
                       choices=['constant', 'linear', 'cosine', 'inverse-square-root'],
                       help='Learning rate decay function.')
    group.add_argument('--lr-decay-iters', type=int, default=None,
                       help='number of iterations to decay learning rate over,'
                       ' If None defaults to `--train-iters`')
    group.add_argument('--lr-decay-samples', type=int, default=None,
                       help='number of samples to decay learning rate over,'
                       ' If None defaults to `--train-samples`')
    group.add_argument('--lr-warmup-fraction', type=float, default=None,
                       help='fraction of lr-warmup-(iters/samples) to use '
                       'for warmup (as a float)')
    group.add_argument('--lr-warmup-iters', type=int, default=0,
                       help='number of iterations to linearly warmup '
                       'learning rate over.')
    group.add_argument('--lr-warmup-samples', type=int, default=0,
                       help='number of samples to linearly warmup '
                       'learning rate over.')
    group.add_argument('--lr-warmup-init', type=float, default=0.0,
                       help='Initial value for learning rate warmup. The '
                       'scheduler starts warmup from this value.')
    group.add_argument('--warmup', type=int, default=None,
                       help='Old lr warmup argument, do not use. Use one of the'
                       '--lr-warmup-* arguments above')
    group.add_argument('--min-lr', type=float, default=0.0,
                       help='Minumum value for learning rate. The scheduler'
                       'clip values below this threshold.')
    group.add_argument('--override-opt_param-scheduler', action='store_true',
                       help='Reset the values of the scheduler (learning rate,'
                       'warmup iterations, minimum learning rate, maximum '
                       'number of iterations, and decay style from input '
                       'arguments and ignore values from checkpoints. Note'
                       'that all the above values will be reset.')
    group.add_argument('--use-checkpoint-opt_param-scheduler', action='store_true',
                       help='Use checkpoint to set the values of the scheduler '
                       '(learning rate, warmup iterations, minimum learning '
                       'rate, maximum number of iterations, and decay style '
                       'from checkpoint and ignore input arguments.')

    return parser

def _add_checkpointing_args(parser):
    group = parser.add_argument_group(title='checkpointing')

    group.add_argument('--save', type=str, default=None,
                       help='Output directory to save checkpoints to.')
    group.add_argument('--save-interval', type=int, default=None,
                       help='Number of iterations between checkpoint saves.')
    group.add_argument('--no-save-optim', action='store_true', default=None,
                       help='Do not save current optimizer.')
    group.add_argument('--no-save-rng', action='store_true', default=None,
                       help='Do not save current rng state.')
    group.add_argument('--load', type=str, default=None,
                       help='Directory containing a model checkpoint.')
    group.add_argument('--no-load-optim', action='store_true', default=None,
                       help='Do not load optimizer when loading checkpoint.')
    group.add_argument('--no-load-rng', action='store_true', default=None,
                       help='Do not load rng state when loading checkpoint.')
    group.add_argument("--load-iteration", type=int, default=0,


                       help='Old lr warmup argument, do not use. Use one of the'
                       '--lr-warmup-* arguments above')
    group.add_argument('--min-lr', type=float, default=0.0,
                       help='Minumum value for learning rate. The scheduler'
                       'clip values below this threshold.')
    group.add_argument('--override-opt_param-scheduler', action='store_true',
                       help='Reset the values of the scheduler (learning rate,'
                       'warmup iterations, minimum learning rate, maximum '
                       'number of iterations, and decay style from input '
                       'arguments and ignore values from checkpoints. Note'
                       'that all the above values will be reset.')
    group.add_argument('--use-checkpoint-opt_param-scheduler', action='store_true',
                       help='Use checkpoint to set the values of the scheduler '
                       '(learning rate, warmup iterations, minimum learning '
                       'rate, maximum number of iterations, and decay style '
                       'from checkpoint and ignore input arguments.')

    return parser

def _add_checkpointing_args(parser):
    group = parser.add_argument_group(title='checkpointing')

    group.add_argument('--save', type=str, default=None,
                       help='Output directory to save checkpoints to.')
    group.add_argument('--save-interval', type=int, default=None,
                       help='Number of iterations between checkpoint saves.')
    group.add_argument('--no-save-optim', action='store_true', default=None,
                       help='Do not save current optimizer.')
    group.add_argument('--no-save-rng', action='store_true', default=None,
                       help='Do not save current rng state.')
    group.add_argument('--load', type=str, default=None,
                       help='Directory containing a model checkpoint.')
    group.add_argument('--no-load-optim', action='store_true', default=None,
                       help='Do not load optimizer when loading checkpoint.')
    group.add_argument('--no-load-rng', action='store_true', default=None,
                       help='Do not load rng state when loading checkpoint.')
    group.add_argument("--load-iteration", type=int, default=0,
                       help='Load the checkpoint of this iteration, '
                       'set 0 to load the latest checkpoint.')
    group.add_argument('--finetune', action='store_true',
                       help='Load model for finetuning. Do not load optimizer '
                       'or rng state from checkpoint and set iteration to 0. '
                       'Assumed when loading a release checkpoint.')
    group.add_argument('--no-initialization', action='store_false',
                       help='Do not perform initialization when building model, '
                       'can reduce startup time when definitely loading from a '
                       'checkpoint',
                       dest='perform_initialization')
    group.add_argument('--use-checkpoint-args', action='store_true',
                       help='Override any command line arguments with arguments '
                       'from the checkpoint')
    group.add_argument('--exit-on-missing-checkpoint', action='store_true',
                       help="If '--load' is set, but checkpoint is not found "
                       "(e.g., path typo), then exit instead of random "
                       "initialization.")

    return parser

def _add_mixed_precision_args(parser):
    group = parser.add_argument_group(title='mixed precision')

    group.add_argument('--fp16', action='store_true',
                       help='Run model in fp16 mode.')
    group.add_argument('--bf16', action='store_true',
                       help='Run model in bfloat16 mode.')
    group.add_argument('--loss-scale', type=float, default=None,
                       help='Static loss scaling, positive power of 2 '
                       'values can improve fp16 convergence. If None, dynamic'
                       'loss scaling is used.')
    group.add_argument('--initial-loss-scale', type=float, default=2**32,
                       help='Initial loss-scale for dynamic loss scaling.')
    group.add_argument('--min-loss-scale', type=float, default=1.0,
                       help='Minimum loss scale for dynamic loss scale.')
    group.add_argument('--loss-scale-window', type=float, default=1000,
                       help='Window over which to raise/lower dynamic scale.')
    group.add_argument('--hysteresis', type=int, default=2,


    group.add_argument('--finetune', action='store_true',
                       help='Load model for finetuning. Do not load optimizer '
                       'or rng state from checkpoint and set iteration to 0. '
                       'Assumed when loading a release checkpoint.')
    group.add_argument('--no-initialization', action='store_false',
                       help='Do not perform initialization when building model, '
                       'can reduce startup time when definitely loading from a '
                       'checkpoint',
                       dest='perform_initialization')
    group.add_argument('--use-checkpoint-args', action='store_true',
                       help='Override any command line arguments with arguments '
                       'from the checkpoint')
    group.add_argument('--exit-on-missing-checkpoint', action='store_true',
                       help="If '--load' is set, but checkpoint is not found "
                       "(e.g., path typo), then exit instead of random "
                       "initialization.")

    return parser

def _add_mixed_precision_args(parser):
    group = parser.add_argument_group(title='mixed precision')

    group.add_argument('--fp16', action='store_true',
                       help='Run model in fp16 mode.')
    group.add_argument('--bf16', action='store_true',
                       help='Run model in bfloat16 mode.')
    group.add_argument('--loss-scale', type=float, default=None,
                       help='Static loss scaling, positive power of 2 '
                       'values can improve fp16 convergence. If None, dynamic'
                       'loss scaling is used.')
    group.add_argument('--initial-loss-scale', type=float, default=2**32,
                       help='Initial loss-scale for dynamic loss scaling.')
    group.add_argument('--min-loss-scale', type=float, default=1.0,
                       help='Minimum loss scale for dynamic loss scale.')
    group.add_argument('--loss-scale-window', type=float, default=1000,
                       help='Window over which to raise/lower dynamic scale.')
    group.add_argument('--hysteresis', type=int, default=2,
                       help='hysteresis for dynamic loss scaling')
    group.add_argument('--fp32-residual-connection', action='store_true',
                       help='Move residual connections to fp32.')
    group.add_argument('--query-key-layer-scaling', action='store_true',
                       help='Scale Q * K^T by 1 / layer-number.',
                       dest='apply_query_key_layer_scaling')
    group.add_argument('--attention-softmax-in-fp32', action='store_true',
                       help='Run attention masking and softmax in fp32. '
                       'This flag is ignored unless '
                       '--no-query-key-layer-scaling is specified.')
    group.add_argument('--accumulate-allreduce-grads-in-fp32',
                       action='store_true',
                       help='Gradient accumulation and all-reduce in fp32.')
    group.add_argument('--fp16-lm-cross-entropy', action='store_true',
                       help='Move the cross entropy unreduced loss calculation'
                       'for lm head to fp16.')

    return parser

def _add_distributed_args(parser):
    group = parser.add_argument_group(title='distributed')

    group.add_argument('--tensor-model-parallel-size', type=int, default=1,
                       help='Degree of tensor model parallelism.')
    group.add_argument('--pipeline-model-parallel-size', type=int, default=1,
                       help='Degree of pipeline model parallelism.')
    group.add_argument('--pipeline-model-parallel-split-rank',
                       type=int, default=None,
                       help='Rank where encoder and decoder should be split.')
    group.add_argument('--model-parallel-size', type=int, default=None,
                       help='Old model parallel argument, do not use. Use '
                       '--tensor-model-parallel-size instead.')
    group.add_argument('--num-layers-per-virtual-pipeline-stage', type=int, default=None,
                       help='Number of layers per virtual pipeline stage')
    group.add_argument('--overlap-p2p-communication',
                       action='store_true',
                       help='overlap pipeline parallel communication with forward and backward chunks',


                       help='hysteresis for dynamic loss scaling')
    group.add_argument('--fp32-residual-connection', action='store_true',
                       help='Move residual connections to fp32.')
    group.add_argument('--query-key-layer-scaling', action='store_true',
                       help='Scale Q * K^T by 1 / layer-number.',
                       dest='apply_query_key_layer_scaling')
    group.add_argument('--attention-softmax-in-fp32', action='store_true',
                       help='Run attention masking and softmax in fp32. '
                       'This flag is ignored unless '
                       '--no-query-key-layer-scaling is specified.')
    group.add_argument('--accumulate-allreduce-grads-in-fp32',
                       action='store_true',
                       help='Gradient accumulation and all-reduce in fp32.')
    group.add_argument('--fp16-lm-cross-entropy', action='store_true',
                       help='Move the cross entropy unreduced loss calculation'
                       'for lm head to fp16.')

    return parser

def _add_distributed_args(parser):
    group = parser.add_argument_group(title='distributed')

    group.add_argument('--tensor-model-parallel-size', type=int, default=1,
                       help='Degree of tensor model parallelism.')
    group.add_argument('--pipeline-model-parallel-size', type=int, default=1,
                       help='Degree of pipeline model parallelism.')
    group.add_argument('--pipeline-model-parallel-split-rank',
                       type=int, default=None,
                       help='Rank where encoder and decoder should be split.')
    group.add_argument('--model-parallel-size', type=int, default=None,
                       help='Old model parallel argument, do not use. Use '
                       '--tensor-model-parallel-size instead.')
    group.add_argument('--num-layers-per-virtual-pipeline-stage', type=int, default=None,
                       help='Number of layers per virtual pipeline stage')
    group.add_argument('--overlap-p2p-communication',
                       action='store_true',
                       help='overlap pipeline parallel communication with forward and backward chunks',
                       dest='overlap_p2p_comm')
    group.add_argument('--distributed-backend', default='nccl',
                       choices=['nccl', 'gloo'],
                       help='Which backend to use for distributed training.')
    group.add_argument('--distributed-timeout-minutes', type=int, default=10,
                       help='Timeout minutes for torch.distributed.')
    group.add_argument('--overlap-grad-reduce', action='store_true',
                       default=False, help='If set, overlap DDP grad reduce.')
    group.add_argument('--no-delay-grad-reduce', action='store_false',
                       help='If not set, delay grad reduction in all but first PP stage.',
                       dest='delay_grad_reduce')
    group.add_argument('--no-scatter-gather-tensors-in-pipeline', action='store_false',
                       help='If not set, use scatter/gather to optimize communication of tensors in pipeline.',
                       dest='scatter_gather_tensors_in_pipeline')
    group.add_argument('--use-ring-exchange-p2p', action='store_true',
                       default=False, help='If set, use custom-built ring exchange '
                       'for p2p communications. Note that this option will require '
                       'a custom built image that support ring-exchange p2p.')
    group.add_argument('--local_rank', type=int, default=None,
                       help='local rank passed from distributed launcher.')
    group.add_argument('--lazy-mpu-init', type=bool, required=False,
                       help='If set to True, initialize_megatron() '
                       'skips DDP initialization and returns function to '
                       'complete it instead.Also turns on '
                       '--use-cpu-initialization flag. This is for '
                       'external DDP manager.' )
    group.add_argument('--use-cpu-initialization', action='store_true',
                       default=None, help='If set, affine parallel weights '
                       'initialization uses CPU' )
    group.add_argument('--empty-unused-memory-level', default=0, type=int,
                       choices=[0, 1, 2],
                       help='Call torch.cuda.empty_cache() each iteration '
                       '(training and eval), to reduce fragmentation.'
                       '0=off, 1=moderate, 2=aggressive.')
    group.add_argument('--standalone-embedding-stage', action='store_true',
                       default=False, help='If set, *input* embedding layer '
                       'is placed on its own pipeline stage, without any '
                       'transformer layers. (For T5, this flag currently only '
                       'affects the encoder embedding.)')
    group.add_argument('--use-distributed-optimizer', action='store_true',
                       help='Use distributed optimizer.')
    group.add_argument('--expert-model-parallel-size', type=int, default=1,
                       help='Degree of expert model parallelism.')
    return parser

def _add_validation_args(parser):
    group = parser.add_argument_group(title='validation')

    group.add_argument('--eval-iters', type=int, default=100,
                       help='Number of iterations to run for evaluation'
                       'validation/test for.')
    group.add_argument('--eval-interval', type=int, default=1000,
                       help='Interval between running evaluation on '
                       'validation set.')
    group.add_argument('--skip-train', action='store_true',
                       default=False, help='If set, bypass the training loop, '
                       'optionally do evaluation for validation/test, and exit.')

    return parser

def _add_data_args(parser):
    group = parser.add_argument_group(title='data and dataloader')


    group.add_argument('--use-cpu-initialization', action='store_true',
                       default=None, help='If set, affine parallel weights '
                       'initialization uses CPU' )
    group.add_argument('--empty-unused-memory-level', default=0, type=int,
                       choices=[0, 1, 2],
                       help='Call torch.cuda.empty_cache() each iteration '
                       '(training and eval), to reduce fragmentation.'
                       '0=off, 1=moderate, 2=aggressive.')
    group.add_argument('--standalone-embedding-stage', action='store_true',
                       default=False, help='If set, *input* embedding layer '
                       'is placed on its own pipeline stage, without any '
                       'transformer layers. (For T5, this flag currently only '
                       'affects the encoder embedding.)')
    group.add_argument('--use-distributed-optimizer', action='store_true',
                       help='Use distributed optimizer.')
    group.add_argument('--expert-model-parallel-size', type=int, default=1,
                       help='Degree of expert model parallelism.')
    return parser

def _add_validation_args(parser):
    group = parser.add_argument_group(title='validation')

    group.add_argument('--eval-iters', type=int, default=100,
                       help='Number of iterations to run for evaluation'
                       'validation/test for.')
    group.add_argument('--eval-interval', type=int, default=1000,
                       help='Interval between running evaluation on '
                       'validation set.')
    group.add_argument('--skip-train', action='store_true',
                       default=False, help='If set, bypass the training loop, '
                       'optionally do evaluation for validation/test, and exit.')

    return parser

def _add_data_args(parser):
    group = parser.add_argument_group(title='data and dataloader')

    group.add_argument('--data-path', nargs='*', default=None,
                       help='Path to the training dataset. Accepted format:'
                       '1) a single data path, 2) multiple datasets in the'
                       'form: dataset1-weight dataset1-path dataset2-weight '
                       'dataset2-path ... It is used with --split when a '
                       'single dataset used for all three: train, valid '
                       'and test. It is exclusive to the other '
                       '--*-data-path args')
    group.add_argument('--split', type=str, default='969, 30, 1',
                       help='Comma-separated list of proportions for training,'
                       ' validation, and test split. For example the split '
                       '`90,5,5` will use 90%% of data for training, 5%% for '
                       'validation and 5%% for test.')
    group.add_argument('--train-data-path', nargs='*', default=None,
                       help='Path to the training dataset. Accepted format:'


                       help='Degree of expert model parallelism.')
    return parser

def _add_validation_args(parser):
    group = parser.add_argument_group(title='validation')

    group.add_argument('--eval-iters', type=int, default=100,
                       help='Number of iterations to run for evaluation'
                       'validation/test for.')
    group.add_argument('--eval-interval', type=int, default=1000,
                       help='Interval between running evaluation on '
                       'validation set.')
    group.add_argument('--skip-train', action='store_true',
                       default=False, help='If set, bypass the training loop, '
                       'optionally do evaluation for validation/test, and exit.')

    return parser

def _add_data_args(parser):
    group = parser.add_argument_group(title='data and dataloader')

    group.add_argument('--data-path', nargs='*', default=None,
                       help='Path to the training dataset. Accepted format:'
                       '1) a single data path, 2) multiple datasets in the'
                       'form: dataset1-weight dataset1-path dataset2-weight '
                       'dataset2-path ... It is used with --split when a '
                       'single dataset used for all three: train, valid '
                       'and test. It is exclusive to the other '
                       '--*-data-path args')
    group.add_argument('--split', type=str, default='969, 30, 1',
                       help='Comma-separated list of proportions for training,'
                       ' validation, and test split. For example the split '
                       '`90,5,5` will use 90%% of data for training, 5%% for '
                       'validation and 5%% for test.')
    group.add_argument('--train-data-path', nargs='*', default=None,
                       help='Path to the training dataset. Accepted format:'
                       '1) a single data path, 2) multiple datasets in the'
                       'form: dataset1-weight dataset1-path dataset2-weight '
                       'dataset2-path ...')
    group.add_argument('--valid-data-path', nargs='*', default=None,
                       help='Path to the validation dataset. Accepted format:'
                       '1) a single data path, 2) multiple datasets in the'
                       'form: dataset1-weight dataset1-path dataset2-weight '
                       'dataset2-path ...')
    group.add_argument('--test-data-path', nargs='*', default=None,
                       help='Path to the test dataset. Accepted format:'
                       '1) a single data path, 2) multiple datasets in the'
                       'form: dataset1-weight dataset1-path dataset2-weight '
                       'dataset2-path ...')
    group.add_argument('--data-cache-path', default=None,
                       help='Path to a directory to hold cached index files.')

    group.add_argument('--vocab-size', type=int, default=None,
                       help='Size of vocab before EOD or padding.')
    group.add_argument('--padded-vocab-size', type=int, default=None,
                       help='Size of vocab after padding.')
    group.add_argument('--vocab-file', type=str, default=None,
                       help='Path to the vocab file.')
    group.add_argument('--merge-file', type=str, default=None,
                       help='Path to the BPE merge file.')
    group.add_argument('--vocab-extra-ids', type=int, default=0,
                       help='Number of additional vocabulary tokens. '
                            'They are used for span masking in the T5 model')
    group.add_argument('--seq-length', type=int, default=None,
                       help='Maximum sequence length to process.')
    group.add_argument('--encoder-seq-length', type=int, default=None,
                       help='Maximum encoder sequence length to process.'
                       'This should be exclusive of --seq-length')
    group.add_argument('--decoder-seq-length', type=int, default=None,
                       help="Maximum decoder sequence length to process.")
    group.add_argument('--retriever-seq-length', type=int, default=256,
                       help='Maximum sequence length for the biencoder model '
                       'for retriever')
    group.add_argument('--sample-rate', type=float, default=1.0,
                       help='sample rate for training data. Supposed to be 0 '
                            ' < sample_rate < 1')
    group.add_argument('--mask-prob', type=float, default=0.15,
                       help='Probability of replacing a token with mask.')
    group.add_argument('--short-seq-prob', type=float, default=0.1,
                       help='Probability of producing a short sequence.')
    group.add_argument('--mmap-warmup', action='store_true',
                       help='Warm up mmap files.')
    group.add_argument('--num-workers', type=int, default=2,
                       help="Dataloader number of workers.")
    group.add_argument('--tokenizer-type', type=str,
                       default=None,
                       choices=['BertWordPieceLowerCase',
                                'BertWordPieceCase',
                                'GPT2BPETokenizer',
                                'SentencePieceTokenizer',
                                'GPTSentencePieceTokenizer',
                                'Llama2Tokenizer',
                                'NullTokenizer'],
                       help='What type of tokenizer to use.')
    group.add_argument('--tokenizer-model', type=str, default=None,
                       help='Sentencepiece tokenizer model.')
    group.add_argument('--reset-position-ids', action='store_true',
                       help='Reset posistion ids after end-of-document token.')
    group.add_argument('--reset-attention-mask', action='store_true',
                       help='Reset self attention maske after '
                       'end-of-document token.')
    group.add_argument('--eod-mask-loss', action='store_true',
                       help='Mask loss for the end of document tokens.')

    return parser

def _add_early_exit_args(parser):
    group = parser.add_argument_group(title='multexit')

    group.add_argument('--exit-layer-nums', type=int, nargs='+', default=[],
                       help='Layer number of early exit layers, start from 1.')
    group.add_argument('--exit-layer-weight', type=float, nargs='+', default=[],
                       help='Loss weight of each early exit layer.')
    group.add_argument('--exit-layer-weight-warmup-iters', default=0, type=int)
    group.add_argument('--exit-layer-weight-warmup-style', default='linear', type=str,
                       choices=['linear', 'cosine'])
    group.add_argument('--exit-layer-weight-init', type=float, nargs='+', default=[])
    group.add_argument('--exit-layer-temperature', type=float, nargs='+', default=[],
                       help='Temperature of each early exit layer.')
    group.add_argument('--use-exit-mlp', action='store_true',
                       help='Use exit mlp in each early exit layer.')
    group.add_argument('--use-exit-block', action='store_true',
                       help='Use a transformer block in each early exit branch')
    group.add_argument('--use-exit-norm', action='store_true',


                                'BertWordPieceCase',
                                'GPT2BPETokenizer',
                                'SentencePieceTokenizer',
                                'GPTSentencePieceTokenizer',
                                'Llama2Tokenizer',
                                'NullTokenizer'],
                       help='What type of tokenizer to use.')
    group.add_argument('--tokenizer-model', type=str, default=None,
                       help='Sentencepiece tokenizer model.')
    group.add_argument('--reset-position-ids', action='store_true',
                       help='Reset posistion ids after end-of-document token.')
    group.add_argument('--reset-attention-mask', action='store_true',
                       help='Reset self attention maske after '
                       'end-of-document token.')
    group.add_argument('--eod-mask-loss', action='store_true',
                       help='Mask loss for the end of document tokens.')

    return parser

def _add_early_exit_args(parser):
    group = parser.add_argument_group(title='multexit')

    group.add_argument('--exit-layer-nums', type=int, nargs='+', default=[],
                       help='Layer number of early exit layers, start from 1.')
    group.add_argument('--exit-layer-weight', type=float, nargs='+', default=[],
                       help='Loss weight of each early exit layer.')
    group.add_argument('--exit-layer-weight-warmup-iters', default=0, type=int)
    group.add_argument('--exit-layer-weight-warmup-style', default='linear', type=str,
                       choices=['linear', 'cosine'])
    group.add_argument('--exit-layer-weight-init', type=float, nargs='+', default=[])
    group.add_argument('--exit-layer-temperature', type=float, nargs='+', default=[],
                       help='Temperature of each early exit layer.')
    group.add_argument('--use-exit-mlp', action='store_true',
                       help='Use exit mlp in each early exit layer.')
    group.add_argument('--use-exit-block', action='store_true',
                       help='Use a transformer block in each early exit branch')
    group.add_argument('--use-exit-norm', action='store_true',
                       help='Use exit norm in each early exit layer')
    group.add_argument('--untie-exit-output-weights', action='store_true',
                       help='Untie output weights of different exit layer')
    group.add_argument('--pre-exit', action='store_true',
                       help='Calcualte early exit output before its transformer layer.')
    # todo @pxc: calculate number of fill warmup/cooldown microbatches automatically
    group.add_argument('--fill-explicit-bubbles', action='store_true')
    group.add_argument('--num-fill-warmup-microbatches', type=int, default=None)
    group.add_argument('--num-fill-cooldown-microbatches', type=int, default=None)
    group.add_argument('--backward-forward-ratio', type=float, default=2.0)
    group.add_argument('--use-dynamic-exit-layer-weight', action='store_true')
    group.add_argument('--tune-exit', action='store_true',
                       help='Only finetune early exit parameters.')
    group.add_argument('--tune-exit-pipeline-parallel-size', type=int, default=1)
    return parser

def _add_autoresume_args(parser):
    group = parser.add_argument_group(title='autoresume')

    group.add_argument('--adlr-autoresume', action='store_true',
                       help='Enable autoresume on adlr cluster.')
    group.add_argument('--adlr-autoresume-interval', type=int, default=1000,
                       help='Intervals over which check for autoresume'
                       'termination signal')

    return parser

def _add_biencoder_args(parser):
    group = parser.add_argument_group(title='biencoder')

    # network size
    group.add_argument('--ict-head-size', type=int, default=None,
                       help='Size of block embeddings to be used in ICT and '


    group.add_argument('--use-exit-block', action='store_true',
                       help='Use a transformer block in each early exit branch')
    group.add_argument('--use-exit-norm', action='store_true',
                       help='Use exit norm in each early exit layer')
    group.add_argument('--untie-exit-output-weights', action='store_true',
                       help='Untie output weights of different exit layer')
    group.add_argument('--pre-exit', action='store_true',
                       help='Calcualte early exit output before its transformer layer.')
    # todo @pxc: calculate number of fill warmup/cooldown microbatches automatically
    group.add_argument('--fill-explicit-bubbles', action='store_true')
    group.add_argument('--num-fill-warmup-microbatches', type=int, default=None)
    group.add_argument('--num-fill-cooldown-microbatches', type=int, default=None)
    group.add_argument('--backward-forward-ratio', type=float, default=2.0)
    group.add_argument('--use-dynamic-exit-layer-weight', action='store_true')
    group.add_argument('--tune-exit', action='store_true',
                       help='Only finetune early exit parameters.')
    group.add_argument('--tune-exit-pipeline-parallel-size', type=int, default=1)
    return parser

def _add_autoresume_args(parser):
    group = parser.add_argument_group(title='autoresume')

    group.add_argument('--adlr-autoresume', action='store_true',
                       help='Enable autoresume on adlr cluster.')
    group.add_argument('--adlr-autoresume-interval', type=int, default=1000,
                       help='Intervals over which check for autoresume'
                       'termination signal')

    return parser

def _add_biencoder_args(parser):
    group = parser.add_argument_group(title='biencoder')

    # network size
    group.add_argument('--ict-head-size', type=int, default=None,
                       help='Size of block embeddings to be used in ICT and '
                        'REALM (paper default: 128)')
    group.add_argument('--biencoder-projection-dim', type=int, default=0,
                       help='Size of projection head used in biencoder (paper'
                        ' default: 128)')
    group.add_argument('--biencoder-shared-query-context-model', action='store_true',
                        help='Whether to share the parameters of the query '
                        'and context models or not')

    # checkpointing
    group.add_argument('--ict-load', type=str, default=None,
                       help='Directory containing an ICTBertModel checkpoint')
    group.add_argument('--bert-load', type=str, default=None,


    group.add_argument('--backward-forward-ratio', type=float, default=2.0)
    group.add_argument('--use-dynamic-exit-layer-weight', action='store_true')
    group.add_argument('--tune-exit', action='store_true',
                       help='Only finetune early exit parameters.')
    group.add_argument('--tune-exit-pipeline-parallel-size', type=int, default=1)
    return parser

def _add_autoresume_args(parser):
    group = parser.add_argument_group(title='autoresume')

    group.add_argument('--adlr-autoresume', action='store_true',
                       help='Enable autoresume on adlr cluster.')
    group.add_argument('--adlr-autoresume-interval', type=int, default=1000,
                       help='Intervals over which check for autoresume'
                       'termination signal')

    return parser

def _add_biencoder_args(parser):
    group = parser.add_argument_group(title='biencoder')

    # network size
    group.add_argument('--ict-head-size', type=int, default=None,
                       help='Size of block embeddings to be used in ICT and '
                        'REALM (paper default: 128)')
    group.add_argument('--biencoder-projection-dim', type=int, default=0,
                       help='Size of projection head used in biencoder (paper'
                        ' default: 128)')
    group.add_argument('--biencoder-shared-query-context-model', action='store_true',
                        help='Whether to share the parameters of the query '
                        'and context models or not')

    # checkpointing
    group.add_argument('--ict-load', type=str, default=None,
                       help='Directory containing an ICTBertModel checkpoint')
    group.add_argument('--bert-load', type=str, default=None,
                       help='Directory containing an BertModel checkpoint '
                       '(needed to start ICT and REALM)')

    # data
    group.add_argument('--titles-data-path', type=str, default=None,
                       help='Path to titles dataset used for ICT')
    group.add_argument('--query-in-block-prob', type=float, default=0.1,
                       help='Probability of keeping query in block for '
                       'ICT dataset')
    group.add_argument('--use-one-sent-docs', action='store_true',
                       help='Whether to use one sentence documents in ICT')
    group.add_argument('--evidence-data-path', type=str, default=None,
                       help='Path to Wikipedia Evidence frm DPR paper')

    # training
    group.add_argument('--retriever-report-topk-accuracies', nargs='+', type=int,
                        default=[], help="Which top-k accuracies to report "
                        "(e.g. '1 5 20')")
    group.add_argument('--retriever-score-scaling', action='store_true',
                       help='Whether to scale retriever scores by inverse '
                        'square root of hidden size')

    # faiss index
    group.add_argument('--block-data-path', type=str, default=None,
                       help='Where to save/load BlockData to/from')
    group.add_argument('--embedding-path', type=str, default=None,
                       help='Where to save/load Open-Retrieval Embedding'
                        ' data to/from')

    # indexer
    group.add_argument('--indexer-batch-size', type=int, default=128,
                       help='How large of batches to use when doing indexing '
                       'jobs')
    group.add_argument('--indexer-log-interval', type=int, default=1000,
                       help='After how many batches should the indexer '
                       'report progress')
    return parser

def _add_vision_args(parser):
    group = parser.add_argument_group(title="vision")

    # general vision arguements
    group.add_argument('--num-classes', type=int, default=1000,
                       help='num of classes in vision classificaiton task')
    group.add_argument('--img-h', type=int, default=224,
                       help='Image height for vision classification task')
    group.add_argument('--img-w', type=int, default=224,
                       help='Image height for vision classification task')
    group.add_argument('--num-channels', type=int, default=3,
                       help='Number of channels in input image data')
    group.add_argument('--patch-dim', type=int, default=16,
                       help='patch dimension')
    group.add_argument('--classes-fraction', type=float, default=1.0,
                       help='training with fraction of classes.')
    group.add_argument('--data-per-class-fraction', type=float, default=1.0,
                       help='training with fraction of data per class.')


                       help='Whether to scale retriever scores by inverse '
                        'square root of hidden size')

    # faiss index
    group.add_argument('--block-data-path', type=str, default=None,
                       help='Where to save/load BlockData to/from')
    group.add_argument('--embedding-path', type=str, default=None,
                       help='Where to save/load Open-Retrieval Embedding'
                        ' data to/from')

    # indexer
    group.add_argument('--indexer-batch-size', type=int, default=128,
                       help='How large of batches to use when doing indexing '
                       'jobs')
    group.add_argument('--indexer-log-interval', type=int, default=1000,
                       help='After how many batches should the indexer '
                       'report progress')
    return parser

def _add_vision_args(parser):
    group = parser.add_argument_group(title="vision")

    # general vision arguements
    group.add_argument('--num-classes', type=int, default=1000,
                       help='num of classes in vision classificaiton task')
    group.add_argument('--img-h', type=int, default=224,
                       help='Image height for vision classification task')
    group.add_argument('--img-w', type=int, default=224,
                       help='Image height for vision classification task')
    group.add_argument('--num-channels', type=int, default=3,
                       help='Number of channels in input image data')
    group.add_argument('--patch-dim', type=int, default=16,
                       help='patch dimension')
    group.add_argument('--classes-fraction', type=float, default=1.0,
                       help='training with fraction of classes.')
    group.add_argument('--data-per-class-fraction', type=float, default=1.0,
                       help='training with fraction of data per class.')
    group.add_argument('--no-data-sharding', action='store_false',
                       help='Disable data sharding.',
                       dest='data_sharding')
    group.add_argument('--head-lr-mult', type=float, default=1.0,
                       help='learning rate multiplier for head during finetuning')

    # pretraining type and backbone selection`
    group.add_argument('--vision-pretraining', action='store_true',
                       help='flag to indicate vision pretraining')
    group.add_argument('--vision-pretraining-type', type=str, default='classify',
                       choices=['classify', 'inpaint', 'dino'],
                       help='pretraining objectives')
    group.add_argument('--vision-backbone-type', type=str, default='vit',
                       choices=['vit', 'mit', 'swin'],
                       help='backbone types types')
    group.add_argument('--swin-backbone-type', type=str, default='tiny',
                       choices=['tiny', 'base', 'h3'],
                       help='pretraining objectives')

    # inpainting arguments
    group.add_argument('--mask-type', type=str, default='random',
                       choices=['random', 'row'],
                       help='mask types')
    group.add_argument('--mask-factor', type=float, default=1.0,
                       help='mask size scaling parameter')

    # dino arguments
    group.add_argument('--iter-per-epoch', type=int, default=1250,
                       help='iterations per epoch')
    group.add_argument('--dino-local-img-size', type=int, default=96,
                       help='Image size for vision classification task')
    group.add_argument('--dino-local-crops-number', type=int, default=10,
                       help='Number of local crops')
    group.add_argument('--dino-head-hidden-size', type=int, default=2048,
                       help='Hidden dimension size in dino head')
    group.add_argument('--dino-bottleneck-size', type=int, default=256,
                       help='Bottle neck dimension in dino head ')
    group.add_argument('--dino-freeze-last-layer', type=float, default=1,
                       help='Freezing last layer weights')
    group.add_argument('--dino-norm-last-layer', action='store_true',
                       help='Disable Norm in last layer.')
    group.add_argument('--dino-warmup-teacher-temp', type=float, default=0.04,
                       help='warump teacher temperature')
    group.add_argument('--dino-teacher-temp', type=float, default=0.07,
                       help='teacher temperature')
    group.add_argument('--dino-warmup-teacher-temp-epochs', type=int, default=30,
                       help='warmup teacher temperaure epochs')

    return parser

def _add_experimental_args(parser):
    group = parser.add_argument_group(title='experimental')

    group.add_argument('--model-spec',
                       type=str, default=None, nargs=2,
                       help='Specify the <module_location function_name> pair '
                            'that returns a spec to customize the transformer '
                            'layer implementation. For more details, check the'
                            '`transformer_layer.py` file that details the use '
                            'of spec based customization.')
    return parser


                       help='Image size for vision classification task')
    group.add_argument('--dino-local-crops-number', type=int, default=10,
                       help='Number of local crops')
    group.add_argument('--dino-head-hidden-size', type=int, default=2048,
                       help='Hidden dimension size in dino head')
    group.add_argument('--dino-bottleneck-size', type=int, default=256,
                       help='Bottle neck dimension in dino head ')
    group.add_argument('--dino-freeze-last-layer', type=float, default=1,
                       help='Freezing last layer weights')
    group.add_argument('--dino-norm-last-layer', action='store_true',
                       help='Disable Norm in last layer.')
    group.add_argument('--dino-warmup-teacher-temp', type=float, default=0.04,
                       help='warump teacher temperature')
    group.add_argument('--dino-teacher-temp', type=float, default=0.07,
                       help='teacher temperature')
    group.add_argument('--dino-warmup-teacher-temp-epochs', type=int, default=30,
                       help='warmup teacher temperaure epochs')

    return parser

def _add_experimental_args(parser):
    group = parser.add_argument_group(title='experimental')

    group.add_argument('--model-spec',
                       type=str, default=None, nargs=2,
                       help='Specify the <module_location function_name> pair '
                            'that returns a spec to customize the transformer '
                            'layer implementation. For more details, check the'
                            '`transformer_layer.py` file that details the use '
                            'of spec based customization.')
    return parser


megatron.checkpointing

# Copyright (c) 2023, NVIDIA CORPORATION. All rights reserved.

"""Input/output checkpointing."""

import os
import random
import sys
import numpy as np

import torch

from megatron import update_num_microbatches
from megatron.core import mpu, tensor_parallel
from .global_vars import get_args
from .utils import (unwrap_model,
                    print_rank_0)

_CHECKPOINT_VERSION = None

def set_checkpoint_version(value):
    global _CHECKPOINT_VERSION
    if _CHECKPOINT_VERSION is not None:
        assert _CHECKPOINT_VERSION == value, \
            "checkpoint versions do not match"
    _CHECKPOINT_VERSION = value

def get_checkpoint_version():
    global _CHECKPOINT_VERSION
    return _CHECKPOINT_VERSION

def check_checkpoint_args(checkpoint_args):
    """Ensure fixed arguments for a model are the same for the input
    arguments and the one retrieved from checkpoint."""
    args = get_args()

    def _compare(arg_name, old_arg_name=None, default=None):
        if old_arg_name is not None:
            ckpt_arg_name = old_arg_name
        else:
            ckpt_arg_name = arg_name
        if default is not None:
            checkpoint_value = getattr(checkpoint_args, ckpt_arg_name, default)
        else:
            checkpoint_value = getattr(checkpoint_args, ckpt_arg_name)
        args_value = getattr(args, arg_name)
        error_message = '{} value from checkpoint ({}) is not equal to the ' \
                        'input argument value ({}).'.format(
                            arg_name, checkpoint_value, args_value)
        assert checkpoint_value == args_value, error_message

    _compare('num_layers')
    _compare('hidden_size')
    _compare('num_attention_heads')
    if args.vocab_file:
        _compare('max_position_embeddings')
        _compare('make_vocab_size_divisible_by')
        _compare('padded_vocab_size')
        _compare('tokenizer_type')
    if args.data_parallel_random_init:
        _compare('data_parallel_random_init')
    if get_checkpoint_version() < 3.0:
        _compare('tensor_model_parallel_size',
                 old_arg_name='model_parallel_size')
    if get_checkpoint_version() >= 3.0:
        _compare('tensor_model_parallel_size')
        _compare('pipeline_model_parallel_size')

def ensure_directory_exists(filename):
    """Build filename's path if it does not already exists."""
    dirname = os.path.dirname(filename)
    os.makedirs(dirname, exist_ok = True)

def get_checkpoint_name(checkpoints_path, iteration, release=False,
                        pipeline_parallel=None,
                        tensor_rank=None, pipeline_rank=None,
                        expert_parallel=None, expert_rank=None):
    """Determine the directory name for this rank's checkpoint."""
    if release:
        directory = 'release'
    else:
        directory = 'iter_{:07d}'.format(iteration)

    # Use both the tensor and pipeline MP rank.
    if pipeline_parallel is None:
        pipeline_parallel = mpu.has_pipeline_parallel()
    if tensor_rank is None:
        tensor_rank = mpu.get_tensor_model_parallel_rank()
    if pipeline_rank is None:
        pipeline_rank = mpu.get_pipeline_model_parallel_rank()
    if expert_parallel is None:
        expert_parallel = (mpu.get_expert_model_parallel_world_size() > 1)
    if expert_rank is None:
        expert_rank = mpu.get_expert_model_parallel_rank()

    # Use both the tensor and pipeline MP rank. If using the distributed
    # optimizer, then the optimizer's path must additionally include the
    # data parallel rank.
    if not pipeline_parallel:
        common_path = os.path.join(checkpoints_path, directory,
                            f'mp_rank_{tensor_rank:02d}')
    else:
        common_path = os.path.join(checkpoints_path, directory,
                f'mp_rank_{tensor_rank:02d}_{pipeline_rank:03d}')

    if expert_parallel:
        common_path = common_path + f'_{expert_rank:03d}'

    return os.path.join(common_path, "model_optim_rng.pt")

def get_distributed_optimizer_checkpoint_name(model_checkpoint_name):
    return os.path.join(os.path.dirname(model_checkpoint_name),
                        "distrib_optim.pt")

def find_checkpoint_rank_0(checkpoints_path, iteration, release=False):
    """Finds the checkpoint for rank 0 without knowing if we are using
    pipeline parallelism/expert parallelism or not.

    Since the checkpoint naming scheme changes if pipeline or expert
    parallelism is present, we need to look for both naming schemes if
    we don't know if the checkpoint has pipeline or expert parallelism.
    """

    # Look for checkpoint with no pipelining and no expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=False,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=False, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    # Look for checkpoint with no pipelining and expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=False,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=True, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    # Look for checkpoint with pipelining and no expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=True,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=False, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    # Look for checkpoint with pipelining and expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=True,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=True, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    return None, None

def get_checkpoint_tracker_filename(checkpoints_path):

    """Tracker file rescords the latest chckpoint during
    training to restart from."""
    return os.path.join(checkpoints_path, 'latest_checkpointed_iteration.txt')

def read_metadata(tracker_filename):
    # Read the tracker file and either set the iteration or
    # mark it as a release checkpoint.
    iteration = 0
    release = False
    with open(tracker_filename, 'r') as f:
        metastring = f.read().strip()
        try:
            iteration = int(metastring)
        except ValueError:
            release = metastring == 'release'
            if not release:
                print_rank_0('ERROR: Invalid metadata file {}. Exiting'.format(
                    tracker_filename))
                sys.exit()
    assert iteration > 0 or release, 'error parsing metadata file {}'.format(
        tracker_filename)

    # Get the max iteration retrieved across the ranks.
    if torch.distributed.is_initialized():
        iters_cuda = torch.cuda.LongTensor([iteration])
        torch.distributed.all_reduce(iters_cuda, op=torch.distributed.ReduceOp.MAX)
        max_iter = iters_cuda[0].item()

        # We should now have all the same iteration.
        # If not, print a warning and chose the maximum
        # iteration across all ranks.
        if iteration != max_iter:
            rank = torch.distributed.get_rank()
            print('WARNING: on rank {} found iteration {} in the '
                  'metadata while max iteration across the ranks '
                  'is {}, replacing it with max iteration.'.format(
                      rank, iteration, max_iter), flush=True)
    else:
        # When loading a checkpoint outside of training (for example,
        # when editing it), we might not have torch distributed
        # initialized, in this case, just assume we have the latest
        max_iter = iteration
    return max_iter, release

def get_rng_state():
    """ collect rng state across data parallel ranks """
    args = get_args()
    rng_state = {
        'random_rng_state': random.getstate(),
        'np_rng_state': np.random.get_state(),
        'torch_rng_state': torch.get_rng_state(),
        'cuda_rng_state': torch.cuda.get_rng_state(),
        'rng_tracker_states': tensor_parallel.get_cuda_rng_tracker().get_states()}

    rng_state_list = None
    if torch.distributed.is_initialized() and \
            mpu.get_data_parallel_world_size() > 1 and \
            args.data_parallel_random_init:
        rng_state_list = \
            [None for i in range(mpu.get_data_parallel_world_size())]
        torch.distributed.all_gather_object(
            rng_state_list,
            rng_state,
            group=mpu.get_data_parallel_group())
    else:
        rng_state_list = [rng_state]

    return rng_state_list

def save_checkpoint(iteration, model, optimizer, opt_param_scheduler):
    """Save a model checkpoint."""
    args = get_args()

    # Only rank zero of the data parallel writes to the disk.
    model = unwrap_model(model)

    print_rank_0('saving checkpoint at iteration {:7d} to {}'.format(
        iteration, args.save))

    # Collect rng state across data parallel ranks.
    rng_state = get_rng_state()

    # Checkpoint name.
    checkpoint_name = get_checkpoint_name(args.save, iteration)

    # Save distributed optimizer's custom parameter state.
    if args.use_distributed_optimizer and not args.no_save_optim and optimizer is not None:
        optim_checkpoint_name = \
            get_distributed_optimizer_checkpoint_name(checkpoint_name)
        ensure_directory_exists(optim_checkpoint_name)
        optimizer.save_parameter_state(optim_checkpoint_name)

    # Collect args, model, RNG.
    if not torch.distributed.is_initialized() \
            or mpu.get_data_modulo_expert_parallel_rank() == 0:

        # Arguments, iteration, and model.
        state_dict = {}
        state_dict['args'] = args
        state_dict['checkpoint_version'] = 3.0
        state_dict['iteration'] = iteration
        if len(model) == 1:
            state_dict['model'] = model[0].state_dict_for_save_checkpoint()
        else:
            for i in range(len(model)):
                mpu.set_virtual_pipeline_model_parallel_rank(i)
                state_dict['model%d' % i] = \
                    model[i].state_dict_for_save_checkpoint()

        # Optimizer stuff.
        if not args.no_save_optim:
            if optimizer is not None:
                state_dict['optimizer'] = optimizer.state_dict()
            if opt_param_scheduler is not None:
                state_dict['opt_param_scheduler'] = \
                    opt_param_scheduler.state_dict()

        # RNG states.
        if not args.no_save_rng:
            state_dict["rng_state"] = rng_state

        # Save.
        ensure_directory_exists(checkpoint_name)
        torch.save(state_dict, checkpoint_name)

    # Wait so everyone is done (necessary)
    if torch.distributed.is_initialized():
        torch.distributed.barrier()

    print_rank_0('  successfully saved checkpoint at iteration {:7d} to {}' \
                 .format(iteration, args.save))

    # And update the latest iteration
    if not torch.distributed.is_initialized() \
       or torch.distributed.get_rank() == 0:
        tracker_filename = get_checkpoint_tracker_filename(args.save)
        with open(tracker_filename, 'w') as f:
            f.write(str(iteration))

    # Wait so everyone is done (not necessary)
    if torch.distributed.is_initialized():
        torch.distributed.barrier()

def _transpose_first_dim(t, num_splits, num_splits_first, model):
    input_shape = t.size()
    # We use a self_attention module but the values extracted aren't
    # specific to self attention so should work for cross attention as well
    while hasattr(model, 'module'):
        model = model.module
    attention_module = model.language_model.encoder.layers[0].self_attention
    hidden_size_per_attention_head = attention_module.hidden_size_per_attention_head
    num_attention_heads_per_partition = attention_module.num_attention_heads_per_partition
    if num_splits_first:
        """[num_splits * np * hn, h]
        -->(view) [num_splits, np, hn, h]
        -->(tranpose) [np, num_splits, hn, h]
        -->(view) [np * num_splits * hn, h] """

        intermediate_shape = \
            (num_splits, num_attention_heads_per_partition,
             hidden_size_per_attention_head) + input_shape[1:]

        t = t.view(*intermediate_shape)
        t = t.transpose(0, 1).contiguous()
    else:
        """[np * hn * num_splits, h]
        -->(view) [np, hn, num_splits, h]
        -->(tranpose) [np, num_splits, hn, h]
        -->(view) [np * num_splits * hn, h] """

        intermediate_shape = \
            (num_attention_heads_per_partition,
             hidden_size_per_attention_head, num_splits) +\
             input_shape[1:]

        t = t.view(*intermediate_shape)
        t = t.transpose(1, 2).contiguous()
    t = t.view(*input_shape)

    return t

def fix_query_key_value_ordering(model, checkpoint_version):
    """Fix up query/key/value matrix ordering if checkpoint
    version is smaller than 2.0
    """
    if checkpoint_version < 2.0:
        if isinstance(model, list):
            assert len(model)==1
            model = model[0]
        for name, param in model.named_parameters():
            if name.endswith(('.query_key_value.weight', '.query_key_value.bias')):
                if checkpoint_version == 0:
                    fixed_param = _transpose_first_dim(param.data, 3, True, model)
                elif checkpoint_version == 1.0:
                    fixed_param = _transpose_first_dim(param.data, 3, False, model)
                else:
                    print_rank_0(f"Invalid checkpoint version {checkpoint_version}.")
                    sys.exit()
                param.data.copy_(fixed_param)
            if name.endswith(('.key_value.weight', '.key_value.bias')):
                if checkpoint_version == 0:
                    fixed_param = _transpose_first_dim(param.data, 2, True, model)
                elif checkpoint_version == 1.0:
                    fixed_param = _transpose_first_dim(param.data, 2, False, model)
                else:
                    print_rank_0(f"Invalid checkpoint version {checkpoint_version}.")
                    sys.exit()
                param.data.copy_(fixed_param)
        print_rank_0(" succesfully fixed query-key-values ordering for"
                     " checkpoint version {}".format(checkpoint_version))

def _load_base_checkpoint(load_dir, rank0=False, load_iteration=0):
    """ Load the base state_dict from the given directory

    If rank0 is true, just loads rank 0 checkpoint, ignoring arguments.
    """

    if load_iteration == 0:
        # Read the tracker file and set the iteration.
        tracker_filename = get_checkpoint_tracker_filename(load_dir)

        # If no tracker file, return nothing
        if not os.path.isfile(tracker_filename):
            if not rank0:
                print_rank_0('WARNING: could not find the metadata file {} '.format(
                    tracker_filename))
                print_rank_0('    will not load any checkpoints and will start from '
                            'random')
            return None, "", False

        # Otherwise, read the tracker file and either set the iteration or
        # mark it as a release checkpoint.
        iteration, release = read_metadata(tracker_filename)
    else:
        iteration = load_iteration
        release = False
    # Checkpoint.
    if rank0:
        checkpoint_name = find_checkpoint_rank_0(load_dir, iteration, release)
    else:
        checkpoint_name = get_checkpoint_name(load_dir, iteration, release)
        if release:
            print_rank_0(f' loading release checkpoint from {load_dir}')
        else:
            print_rank_0(f' loading checkpoint from {load_dir} at iteration {iteration}')

    # Load the checkpoint.
    try:
        state_dict = torch.load(checkpoint_name, map_location='cpu')
    except ModuleNotFoundError:
        from megatron.fp16_deprecated import loss_scaler
        # For backward compatibility.
        if not rank0:
            print_rank_0(' > deserializing using the old code structure ...')
        sys.modules['fp16.loss_scaler'] = sys.modules[
            'megatron.fp16_deprecated.loss_scaler']
        sys.modules['megatron.fp16.loss_scaler'] = sys.modules[
            'megatron.fp16_deprecated.loss_scaler']
        state_dict = torch.load(checkpoint_name, map_location='cpu')
        sys.modules.pop('fp16.loss_scaler', None)
        sys.modules.pop('megatron.fp16.loss_scaler', None)
    except BaseException as e:
        print_rank_0('could not load the checkpoint')
        print_rank_0(e)
        sys.exit()

    return state_dict, checkpoint_name, release

def load_args_from_checkpoint(args, load_arg='load'):
    """Set required arguments from the checkpoint specified in the
    arguments.

    Will overwrite arguments that have a non-None default value, but
    will leave any arguments that default to None as set.

    Returns the same args NameSpace with the new values added/updated.

    If no checkpoint is specified in args, or if the checkpoint is
    there but invalid, the arguments will not be modified

    """
    load_dir = getattr(args, load_arg)

    if load_dir is None:
        print_rank_0('No load directory specified, using provided arguments.')
        return args

    state_dict, checkpoint_name, release = _load_base_checkpoint(load_dir, rank0=True, load_iteration=args.load_iteration)

    # Args.
    if not state_dict:
        print_rank_0('Checkpoint not found to provide arguments, using provided arguments.')
        return args

    if 'args' not in state_dict:
        print_rank_0('Checkpoint provided does not have arguments saved, using provided arguments.')
        return args

    checkpoint_args = state_dict['args']
    checkpoint_version = state_dict.get('checkpoint_version', 0)
    args.iteration = state_dict['iteration']

    # One-off conversion for foundation models
    if hasattr(checkpoint_args, 'disable_bias_linear'):
        setattr(checkpoint_args, 'add_bias_linear', not getattr(checkpoint_args, 'disable_bias_linear'))

    def _set_arg(arg_name, old_arg_name=None, force=False):
        if not force and getattr(args, arg_name, None) is not None:
            return

        if old_arg_name is not None:
            checkpoint_value = getattr(checkpoint_args, old_arg_name, None)
        else:
            checkpoint_value = getattr(checkpoint_args, arg_name, None)

        if checkpoint_value is not None:
            print_rank_0(f"Setting {arg_name} to {checkpoint_value} from checkpoint")
            setattr(args, arg_name, checkpoint_value)
        else:
            print_rank_0(f"Checkpoint did not provide arguments {arg_name}")

    _set_arg('num_layers')
    _set_arg('hidden_size')
    _set_arg('ffn_hidden_size')
    _set_arg('seq_length')
    _set_arg('num_attention_heads')
    _set_arg('num_query_groups', force=True)
    _set_arg('group_query_attention', force=True)
    _set_arg('kv_channels')
    _set_arg('max_position_embeddings')
    _set_arg('position_embedding_type', force=True)
    _set_arg('add_position_embedding', force=True)
    _set_arg('use_rotary_position_embeddings', force=True)
    _set_arg('rotary_percent', force=True)
    _set_arg('add_bias_linear', force=True)
    _set_arg('swiglu', force=True)
    _set_arg('untie_embeddings_and_output_weights', force=True)
    _set_arg('apply_layernorm_1p', force=True)
    _set_arg('normalization', force=True)
    _set_arg('tokenizer_type')
    _set_arg('padded_vocab_size')
    _set_arg('make_vocab_size_divisible_by
# ... truncated ...


"""Input/output checkpointing."""

import os
import random
import sys
import numpy as np

import torch

from megatron import update_num_microbatches
from megatron.core import mpu, tensor_parallel
from .global_vars import get_args
from .utils import (unwrap_model,
                    print_rank_0)

_CHECKPOINT_VERSION = None

def set_checkpoint_version(value):
    global _CHECKPOINT_VERSION
    if _CHECKPOINT_VERSION is not None:
        assert _CHECKPOINT_VERSION == value, \
            "checkpoint versions do not match"
    _CHECKPOINT_VERSION = value

def get_checkpoint_version():
    global _CHECKPOINT_VERSION
    return _CHECKPOINT_VERSION

def check_checkpoint_args(checkpoint_args):
    """Ensure fixed arguments for a model are the same for the input
    arguments and the one retrieved from checkpoint."""
    args = get_args()

    def _compare(arg_name, old_arg_name=None, default=None):
        if old_arg_name is not None:
            ckpt_arg_name = old_arg_name
        else:
            ckpt_arg_name = arg_name
        if default is not None:
            checkpoint_value = getattr(checkpoint_args, ckpt_arg_name, default)
        else:


import torch

from megatron import update_num_microbatches
from megatron.core import mpu, tensor_parallel
from .global_vars import get_args
from .utils import (unwrap_model,
                    print_rank_0)

_CHECKPOINT_VERSION = None

def set_checkpoint_version(value):
    global _CHECKPOINT_VERSION
    if _CHECKPOINT_VERSION is not None:
        assert _CHECKPOINT_VERSION == value, \
            "checkpoint versions do not match"
    _CHECKPOINT_VERSION = value

def get_checkpoint_version():
    global _CHECKPOINT_VERSION
    return _CHECKPOINT_VERSION

def check_checkpoint_args(checkpoint_args):
    """Ensure fixed arguments for a model are the same for the input
    arguments and the one retrieved from checkpoint."""
    args = get_args()

    def _compare(arg_name, old_arg_name=None, default=None):
        if old_arg_name is not None:
            ckpt_arg_name = old_arg_name
        else:
            ckpt_arg_name = arg_name
        if default is not None:
            checkpoint_value = getattr(checkpoint_args, ckpt_arg_name, default)
        else:
            checkpoint_value = getattr(checkpoint_args, ckpt_arg_name)
        args_value = getattr(args, arg_name)
        error_message = '{} value from checkpoint ({}) is not equal to the ' \
                        'input argument value ({}).'.format(
                            arg_name, checkpoint_value, args_value)


from .utils import (unwrap_model,
                    print_rank_0)

_CHECKPOINT_VERSION = None

def set_checkpoint_version(value):
    global _CHECKPOINT_VERSION
    if _CHECKPOINT_VERSION is not None:
        assert _CHECKPOINT_VERSION == value, \
            "checkpoint versions do not match"
    _CHECKPOINT_VERSION = value

def get_checkpoint_version():
    global _CHECKPOINT_VERSION
    return _CHECKPOINT_VERSION

def check_checkpoint_args(checkpoint_args):
    """Ensure fixed arguments for a model are the same for the input
    arguments and the one retrieved from checkpoint."""
    args = get_args()

    def _compare(arg_name, old_arg_name=None, default=None):
        if old_arg_name is not None:
            ckpt_arg_name = old_arg_name
        else:
            ckpt_arg_name = arg_name
        if default is not None:
            checkpoint_value = getattr(checkpoint_args, ckpt_arg_name, default)
        else:
            checkpoint_value = getattr(checkpoint_args, ckpt_arg_name)
        args_value = getattr(args, arg_name)
        error_message = '{} value from checkpoint ({}) is not equal to the ' \
                        'input argument value ({}).'.format(
                            arg_name, checkpoint_value, args_value)
        assert checkpoint_value == args_value, error_message

    _compare('num_layers')
    _compare('hidden_size')
    _compare('num_attention_heads')
    if args.vocab_file:
        _compare('max_position_embeddings')
        _compare('make_vocab_size_divisible_by')
        _compare('padded_vocab_size')
        _compare('tokenizer_type')
    if args.data_parallel_random_init:
        _compare('data_parallel_random_init')
    if get_checkpoint_version() < 3.0:
        _compare('tensor_model_parallel_size',
                 old_arg_name='model_parallel_size')
    if get_checkpoint_version() >= 3.0:
        _compare('tensor_model_parallel_size')
        _compare('pipeline_model_parallel_size')

def ensure_directory_exists(filename):
    """Build filename's path if it does not already exists."""
    dirname = os.path.dirname(filename)
    os.makedirs(dirname, exist_ok = True)

def get_checkpoint_name(checkpoints_path, iteration, release=False,
                        pipeline_parallel=None,
                        tensor_rank=None, pipeline_rank=None,
                        expert_parallel=None, expert_rank=None):
    """Determine the directory name for this rank's checkpoint."""
    if release:
        directory = 'release'
    else:
        directory = 'iter_{:07d}'.format(iteration)

    # Use both the tensor and pipeline MP rank.
    if pipeline_parallel is None:


        assert checkpoint_value == args_value, error_message

    _compare('num_layers')
    _compare('hidden_size')
    _compare('num_attention_heads')
    if args.vocab_file:
        _compare('max_position_embeddings')
        _compare('make_vocab_size_divisible_by')
        _compare('padded_vocab_size')
        _compare('tokenizer_type')
    if args.data_parallel_random_init:
        _compare('data_parallel_random_init')
    if get_checkpoint_version() < 3.0:
        _compare('tensor_model_parallel_size',
                 old_arg_name='model_parallel_size')
    if get_checkpoint_version() >= 3.0:
        _compare('tensor_model_parallel_size')
        _compare('pipeline_model_parallel_size')

def ensure_directory_exists(filename):
    """Build filename's path if it does not already exists."""
    dirname = os.path.dirname(filename)
    os.makedirs(dirname, exist_ok = True)

def get_checkpoint_name(checkpoints_path, iteration, release=False,
                        pipeline_parallel=None,
                        tensor_rank=None, pipeline_rank=None,
                        expert_parallel=None, expert_rank=None):
    """Determine the directory name for this rank's checkpoint."""
    if release:
        directory = 'release'
    else:
        directory = 'iter_{:07d}'.format(iteration)

    # Use both the tensor and pipeline MP rank.
    if pipeline_parallel is None:
        pipeline_parallel = mpu.has_pipeline_parallel()
    if tensor_rank is None:
        tensor_rank = mpu.get_tensor_model_parallel_rank()
    if pipeline_rank is None:
        pipeline_rank = mpu.get_pipeline_model_parallel_rank()
    if expert_parallel is None:


        _compare('max_position_embeddings')
        _compare('make_vocab_size_divisible_by')
        _compare('padded_vocab_size')
        _compare('tokenizer_type')
    if args.data_parallel_random_init:
        _compare('data_parallel_random_init')
    if get_checkpoint_version() < 3.0:
        _compare('tensor_model_parallel_size',
                 old_arg_name='model_parallel_size')
    if get_checkpoint_version() >= 3.0:
        _compare('tensor_model_parallel_size')
        _compare('pipeline_model_parallel_size')

def ensure_directory_exists(filename):
    """Build filename's path if it does not already exists."""
    dirname = os.path.dirname(filename)
    os.makedirs(dirname, exist_ok = True)

def get_checkpoint_name(checkpoints_path, iteration, release=False,
                        pipeline_parallel=None,
                        tensor_rank=None, pipeline_rank=None,
                        expert_parallel=None, expert_rank=None):
    """Determine the directory name for this rank's checkpoint."""
    if release:
        directory = 'release'
    else:
        directory = 'iter_{:07d}'.format(iteration)

    # Use both the tensor and pipeline MP rank.
    if pipeline_parallel is None:
        pipeline_parallel = mpu.has_pipeline_parallel()
    if tensor_rank is None:
        tensor_rank = mpu.get_tensor_model_parallel_rank()
    if pipeline_rank is None:
        pipeline_rank = mpu.get_pipeline_model_parallel_rank()
    if expert_parallel is None:
        expert_parallel = (mpu.get_expert_model_parallel_world_size() > 1)
    if expert_rank is None:
        expert_rank = mpu.get_expert_model_parallel_rank()

    # Use both the tensor and pipeline MP rank. If using the distributed
    # optimizer, then the optimizer's path must additionally include the
    # data parallel rank.
    if not pipeline_parallel:
        common_path = os.path.join(checkpoints_path, directory,
                            f'mp_rank_{tensor_rank:02d}')
    else:
        common_path = os.path.join(checkpoints_path, directory,
                f'mp_rank_{tensor_rank:02d}_{pipeline_rank:03d}')

    if expert_parallel:
        common_path = common_path + f'_{expert_rank:03d}'

    return os.path.join(common_path, "model_optim_rng.pt")

def get_distributed_optimizer_checkpoint_name(model_checkpoint_name):
    return os.path.join(os.path.dirname(model_checkpoint_name),
                        "distrib_optim.pt")

def find_checkpoint_rank_0(checkpoints_path, iteration, release=False):
    """Finds the checkpoint for rank 0 without knowing if we are using
    pipeline parallelism/expert parallelism or not.

    Since the checkpoint naming scheme changes if pipeline or expert
    parallelism is present, we need to look for both naming schemes if
    we don't know if the checkpoint has pipeline or expert parallelism.
    """

    # Look for checkpoint with no pipelining and no expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=False,
                                   tensor_rank=0, pipeline_rank=0,


        expert_parallel = (mpu.get_expert_model_parallel_world_size() > 1)
    if expert_rank is None:
        expert_rank = mpu.get_expert_model_parallel_rank()

    # Use both the tensor and pipeline MP rank. If using the distributed
    # optimizer, then the optimizer's path must additionally include the
    # data parallel rank.
    if not pipeline_parallel:
        common_path = os.path.join(checkpoints_path, directory,
                            f'mp_rank_{tensor_rank:02d}')
    else:
        common_path = os.path.join(checkpoints_path, directory,
                f'mp_rank_{tensor_rank:02d}_{pipeline_rank:03d}')

    if expert_parallel:
        common_path = common_path + f'_{expert_rank:03d}'

    return os.path.join(common_path, "model_optim_rng.pt")

def get_distributed_optimizer_checkpoint_name(model_checkpoint_name):
    return os.path.join(os.path.dirname(model_checkpoint_name),
                        "distrib_optim.pt")

def find_checkpoint_rank_0(checkpoints_path, iteration, release=False):
    """Finds the checkpoint for rank 0 without knowing if we are using
    pipeline parallelism/expert parallelism or not.

    Since the checkpoint naming scheme changes if pipeline or expert
    parallelism is present, we need to look for both naming schemes if
    we don't know if the checkpoint has pipeline or expert parallelism.
    """

    # Look for checkpoint with no pipelining and no expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=False,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=False, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    # Look for checkpoint with no pipelining and expert parallelism


    # optimizer, then the optimizer's path must additionally include the
    # data parallel rank.
    if not pipeline_parallel:
        common_path = os.path.join(checkpoints_path, directory,
                            f'mp_rank_{tensor_rank:02d}')
    else:
        common_path = os.path.join(checkpoints_path, directory,
                f'mp_rank_{tensor_rank:02d}_{pipeline_rank:03d}')

    if expert_parallel:
        common_path = common_path + f'_{expert_rank:03d}'

    return os.path.join(common_path, "model_optim_rng.pt")

def get_distributed_optimizer_checkpoint_name(model_checkpoint_name):
    return os.path.join(os.path.dirname(model_checkpoint_name),
                        "distrib_optim.pt")

def find_checkpoint_rank_0(checkpoints_path, iteration, release=False):
    """Finds the checkpoint for rank 0 without knowing if we are using
    pipeline parallelism/expert parallelism or not.

    Since the checkpoint naming scheme changes if pipeline or expert
    parallelism is present, we need to look for both naming schemes if
    we don't know if the checkpoint has pipeline or expert parallelism.
    """

    # Look for checkpoint with no pipelining and no expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=False,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=False, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    # Look for checkpoint with no pipelining and expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=False,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=True, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    # Look for checkpoint with pipelining and no expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=True,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=False, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    # Look for checkpoint with pipelining and expert parallelism
    filename = get_checkpoint_name(checkpoints_path, iteration, release,
                                   pipeline_parallel=True,
                                   tensor_rank=0, pipeline_rank=0,
                                   expert_parallel=True, expert_rank=0)
    if os.path.isfile(filename):
        return filename

    return None, None

def get_checkpoint_tracker_filename(checkpoints_path):

    """Tracker file rescords the latest chckpoint during
    training to restart from."""
    return os.path.join(checkpoints_path, 'latest_checkpointed_iteration.txt')

def read_metadata(tracker_filename):
    # Read the tracker file and either set the iteration or
    # mark it as a release checkpoint.
    iteration = 0
    release = False
    with open(tracker_filename, 'r') as f:
        metastring = f.read().strip()
        try:
            iteration = int(metastring)
        except ValueError:
            release = metastring == 'release'