Fix the default userbuffer communicator init settings (#755)

fix the default userbuffer communicator init settings
Signed-off-by: Sangkug Lym <slym@nvidia.com>

transformer_engine/pytorch/module/base.py

@@ -153,13 +153,13 @@ def initialize_ub(
     def add_ub(
         name: str,
         method: str,
+        is_reduce_scatter: int,
         num_sm: int = 16,
         cga_size: int = 2,
         set_sm_margin: int = 0,
-        num_splits: int = 4,
+        num_splits: int = 0,
         aggregate: int = 0,
         atomic_gemm: int = 0,
-        is_reduce_scatter: int = 0,
         fp8_buf: bool = False,
     ) -> None:
         if atomic_gemm:
@@ -243,7 +243,7 @@ def initialize_ub(
             method = ub_cfg.get("method", get_method(name))
             num_sm = ub_cfg.get("num_sm", 16)
             cga_size = ub_cfg.get("cga_size", 2)
-            num_splits = ub_cfg.get("num_splits", 4)
+            num_splits = ub_cfg.get("num_splits", 4 if method == "pipeline" else 0)
             set_sm_margin = ub_cfg.get("set_sm_margin", 0)
             aggregate = ub_cfg.get("aggregate", 0)
             atomic_gemm = ub_cfg.get("atomic_gemm", 0)
@@ -254,21 +254,24 @@ def initialize_ub(
             add_ub(
                 name,
                 method,
+                is_reduce_scatter,
                 num_sm,
                 cga_size,
                 set_sm_margin,
                 num_splits,
                 aggregate,
                 atomic_gemm,
-                is_reduce_scatter,
                 fp8_buf,
             )
         else:
             method = get_method(name)
-            if method == "pipeline":
-                add_ub(name, method)
-            else:
-                add_ub(name, method, num_splits=0)
+            add_ub(
+                name,
+                method=method,
+                is_reduce_scatter=1 if name in layers_reduce_scatter_overlap else 0,
+                num_splits=4 if method == "pipeline" else 0,
+                fp8_buf=name in layers_all_gather_overlap,
+            )
 
 
 def get_ub(name: str):