fix perf bugs of mp in eager dygraph (#45646)

python/paddle/distributed/collective.py

@@ -1402,9 +1402,9 @@ def _mp_allreduce(tensor,
     """
     if group is not None and not group.is_member():
         return
-    ring_id = 0 if group is None else group.id
 
     if in_dygraph_mode():
+        group = _get_default_group() if group is None else group
         assert op == ReduceOp.SUM, "Unknown parameter: {}.".format(op)
 
         from paddle.autograd import PyLayer
@@ -1412,14 +1412,19 @@ def _mp_allreduce(tensor,
         class mp_allreduce_eager(PyLayer):
 
             @staticmethod
-            def forward(ctx, tensor, use_calc_stream, ring_id,
+            def forward(ctx, tensor, group, use_calc_stream,
                         use_model_parallel):
-                ctx.ring_id = ring_id
-                return _legacy_C_ops.c_allreduce_sum_(tensor, 'use_calc_stream',
-                                                      use_calc_stream,
-                                                      'ring_id', ring_id,
-                                                      "use_model_parallel",
-                                                      use_model_parallel)
+                ctx.ring_id = group.id
+
+                if use_calc_stream:
+                    op_type = _get_reduce_op(op, "_mp_allreduce")
+                    group.process_group.allreduce_on_calc_stream(
+                        tensor, op_type)
+                    return tensor
+                else:
+                    return _legacy_C_ops.c_allreduce_sum_(
+                        tensor, 'use_calc_stream', use_calc_stream, 'ring_id',
+                        ring_id, "use_model_parallel", use_model_parallel)
 
             @staticmethod
             def backward(ctx, dy):
@@ -1427,10 +1432,11 @@ def _mp_allreduce(tensor,
                                                 'ring_id', ctx.ring_id,
                                                 'use_model_parallel', True)
 
-        return mp_allreduce_eager.apply(tensor, use_calc_stream, ring_id,
+        return mp_allreduce_eager.apply(tensor, group, use_calc_stream,
                                         use_model_parallel)
 
-    elif _in_legacy_dygraph():
+    ring_id = 0 if group is None else group.id
+    if _in_legacy_dygraph():
         if op == ReduceOp.SUM:
             return _legacy_C_ops.c_allreduce_sum_(tensor, 'use_calc_stream',
                                                   use_calc_stream, 'ring_id',