Add Param Cache For Recompilation (#2000)

add param cache

Author: zhenglongjiepheonix

optimum/fx/parallelization/core.py

@@ -125,6 +125,11 @@ class ParallelExecutionCtx:
             because we have to make sure we don't initiate new parameters and replace original ones when
             recompilation happens in training process.
 
+        - param_cache (`Dict[str, nn.Parameter]`):
+            Cache which keeps record of newly created parameters. Similar to `parallel_layer_cache`, we
+            need to make sure all the newly created parameters in the first compilation will still be used
+            when recompilation happens.
+
         - weight_map (`Dict[str, str]`):
             Mapping between parameter names and their locations on disk, useful when loading weights
             from disk.
@@ -140,6 +145,7 @@ class ParallelExecutionCtx:
     current_device: torch.device
     example_inputs: List[Any] = field(default_factory=list)
     parallel_layer_cache: Dict[str, nn.Module] = field(default_factory=dict)
+    param_cache: Dict[str, nn.Parameter] = field(default_factory=dict)
     weight_map: Dict[str, str] = field(default_factory=dict)
     last_optimized_graph_module: Optional[GraphModule] = None
     compile_times: int = 0

optimum/fx/parallelization/passes.py

@@ -480,18 +480,21 @@ def run(self, graph_module: GraphModule, ctx: ParallelExecutionCtx, config: Conf
 
 class InitializeOrLoadWeightsPass(PassBase):
     """
-    Make weights loading/initialization a seperate pass for cleaner logic and easier extensibility. This
-    pass will only run once in the very first compilation step.
+    Weights loading and intialization pass, will initialize parameters on current rank and load weights from disk
+    if necessary.
     """
 
-    need_rerun_when_recompile = False
-
     def run(self, graph_module: GraphModule, ctx: ParallelExecutionCtx, config: Config) -> GraphModule:
         world_size = dist.get_world_size(ctx.tp_group)
         tp_rank = dist.get_rank(ctx.tp_group)
 
-        new_parameters, tied_parameters = [], {}
+        new_parameters, tied_parameters, param_cache = [], {}, ctx.param_cache
         for name, param in sorted(graph_module.named_parameters(remove_duplicate=False)):
+            # skip initializing new params when recompilation happens
+            if name in param_cache:
+                new_parameters.append((name, param_cache[name]))
+                continue
+
             param_meta: ParameterMeta = getattr(param, "meta")
             # skip already initialized/loaded tied parameters
             if param_meta.is_tied and id(param) in tied_parameters:
@@ -569,6 +572,8 @@ def run(self, graph_module: GraphModule, ctx: ParallelExecutionCtx, config: Conf
             else:
                 parent_mod = graph_module
                 field = name
+            if name not in param_cache:
+                param_cache[name] = new_param
             setattr(parent_mod, field, new_param)
 
         return graph_module