added for pp

megatron/arguments.py

@@ -240,10 +240,10 @@ def parse_args(extra_args_provider=None, defaults={},
             'residual connection in fp32 only supported when using fp16 or bf16.'
     # Activation checkpointing.
     if args.distribute_checkpointed_activations:
+        assert args.tensor_model_parallel_size > 1
         assert args.activations_checkpoint_method is not None, \
             'for distribute-checkpointed-activations to work you '\
             'need to use a valid checkpoint-activation method (\'uniform\' or \'block\')'
-        assert args.pipeline_model_parallel_size == 1
 
     _print_args(args)
     return args

megatron/model/transformer.py

@@ -616,7 +616,7 @@ class ParallelTransformer(MegatronModule):
             while l < self.num_layers:
                 hidden_states = mpu.checkpoint(
                     custom(l, l + self.activations_checkpoint_num_layers),
-                    self.distribute_checkpointed_activations,
+                    self.distribute_checkpointed_activations and ( (l > 0) or (mpu.get_pipeline_model_parallel_rank() == 0)),
                     hidden_states, attention_mask, encoder_output, enc_dec_attn_mask)
                 l += self.activations_checkpoint_num_layers
         elif self.activations_checkpoint_method == 'block':
@@ -627,7 +627,7 @@ class ParallelTransformer(MegatronModule):
                 if l < self.activations_checkpoint_num_layers:
                     hidden_states = mpu.checkpoint(
                         custom(l, l + 1),
-                        self.distribute_checkpointed_activations,
+                        self.distribute_checkpointed_activations and ( (l > 0) or (mpu.get_pipeline_model_parallel_rank() == 0)),
                         hidden_states, attention_mask, encoder_output, enc_dec_attn_mask)
                 else:
                     hidden_states = custom(l, l + 1)(