basic chunk

chunk_codegen.py

@@ -46,6 +46,19 @@ def pack_hook_no_input(self, x):
     return pack_hook, unpack_hook
 
 
+def _gen_loop_5(to_keep):
+    context = "chunk_result = []\nfor gen_loop_idx in range(4):\n"
+    context += "    chunk_tensor = " + to_keep + "[gen_loop_idx, :]\n"
+    return context
+
+
+def _gen_loop_5_final(final_name, to_keep):
+    context = "    chunk_result.append(" + final_name + ")\n"
+    context += "chunk_result = torch.cat(chunk_result, dim=0);  " + to_keep[0] + " = None\n"
+    context += final_name + " = chunk_result; chunk_result = None\n"
+    return context
+
+    
 def _gen_save_tensors_hooks_context(offload_input=True) -> str:
     """Generate customized saved_tensors_hooks
 
@@ -410,57 +423,40 @@ def emit_code_with_chunk(body, ckpt_func, nodes, emit_node_func, delete_unused_v
 
     # this flag is to prevent repeated insert of save tensors
     # hooks definition in ckpt_func
-    is_hook_inserted = False
     node_idx = 0
-    while 1:
+    to_keep = []
+    while node_idx < len(node_list):
         # break if we finish the processing all the nodes
         if node_idx >= len(node_list):
             break
 
-        # process ckpt_regions
-        if node_idx in start_idx:
-            ckpt_node_list = node_list[node_idx:end_idx[start_idx.index(node_idx)] + 1]
-            emit_ckpt_func(body, ckpt_func, ckpt_node_list, emit_node_func, delete_unused_value_func)
-            node_idx += len(ckpt_node_list)
-
         # process node in forward function
         else:
             node = node_list[node_idx]
 
             if node_idx in chunk_starts:
-                chunk_label = chunk_labels[chunk_starts.index(node_idx)]
-                _, chunk_input, chunk_bar = chunk_label
+                # save chunk input var, dont delete it
+                to_keep.extend(node.args[0].name)
                 within_chunk_region = True
-
-                # insert hook functions if needed
-                if not is_hook_inserted:
-                    pack_hook, unpack_hook = _gen_saved_tensors_hooks()
-                    ckpt_func.insert(0, "\n".join([pack_hook, unpack_hook]) + "\n")
-                    is_hook_inserted = True
-
-                if chunk_input and chunk_bar:
-                    body.append(_gen_save_on_cpu_context())
-
-                elif chunk_input:
-                    for par in chunk_inputs[chunk_label[0]]:
-                        body.append(f"setattr({par}, 'offload', True)\n")
-                    body.append(_gen_save_tensors_hooks_context(offload_input=True))
-
-                else:
-                    for par in chunk_inputs[chunk_label[0]]:
-                        body.append(f"setattr({par}, 'offload', False)\n")
-                    body.append(_gen_save_tensors_hooks_context(offload_input=False))
+                # add for loop
+                body.append(_gen_loop_5(to_keep[0]))
+                # change first node's input to new chunked var
+                node_args = list(node.args)
+                node_args[0] = 'chunk_tensor'
 
             if within_chunk_region:
                 emit_node_func(node, body)
                 body[-1] = '    ' + body[-1]
-                delete_unused_value_func(node, body)
+                delete_unused_value_func(node, body, to_keep)
 
             else:
                 emit_node_func(node, body)
-                delete_unused_value_func(node, body)
+                if node_idx not in chunk_inputs:
+                    delete_unused_value_func(node, body, to_keep)
 
             if node_idx in chunk_ends:
+                body.append(_gen_loop_5_final(node.name, to_keep))
+                to_keep = []
                 within_chunk_region = False
 
             node_idx += 1
@@ -572,7 +568,7 @@ if CODEGEN_AVAILABLE:
                 map_arg(node.kwargs, lambda n: register_last_uses(n, node))
 
             # NOTE: we add a variable to distinguish body and ckpt_func
-            def delete_unused_values(user: Node, body):
+            def delete_unused_values(user: Node, body, to_keep=[]):
                 """
                 Delete values after their last use. This ensures that values that are
                 not used in the remainder of the code are freed and the memory usage
@@ -584,6 +580,9 @@ if CODEGEN_AVAILABLE:
                     body.append('\n')
                     return
                 nodes_to_delete = user_to_last_uses.get(user, [])
+                for n in nodes_to_delete:
+                    if n.name in to_keep:
+                        nodes_to_delete.remove(n)
                 if len(nodes_to_delete):
                     to_delete_str = ' = '.join([repr(n) for n in nodes_to_delete] + ['None'])
                     body.append(f';  {to_delete_str}\n')
@@ -693,5 +692,6 @@ if CODEGEN_AVAILABLE:
 {wrap_stmts}
 
 {prologue}
-{code}"""
+{code}"""   
+            print(fn_code)
             return PythonCode(fn_code, globals_)

chunk_codegen_run.py

@@ -54,6 +54,7 @@ def _test_fwd_and_bwd(model: torch.nn.Module, gm: ColoGraphModule, data: torch.T
     # test forward
     non_fx_out = model(data)
     fx_out = gm(data)
+    print(non_fx_out.shape, fx_out.shape)
     assert torch.equal(non_fx_out, fx_out), "fx_out doesn't comply with original output"
 
     # test barckward
@@ -86,13 +87,13 @@ def _run_offload_codegen(rank):
             setattr(node, "activation_offload", [0, True, False])
         if node.name == "linear1":
             setattr(node, "activation_offload", [0, True, False])
-        if node.name == "linear2":
-            setattr(node, "activation_offload", [1, True, True])
-        if node.name == "linear4":
-            setattr(node, "activation_offload", [2, False, True])
-        if node.name == "linear5":
-            setattr(node, "activation_checkpoint", [0])
-            setattr(node, "activation_offload", True)
+        # if node.name == "linear2":
+        #     setattr(node, "activation_offload", [1, True, True])
+        # if node.name == "linear4":
+        #     setattr(node, "activation_offload", [2, False, True])
+        # if node.name == "linear5":
+        #     setattr(node, "activation_checkpoint", [0])
+        #     setattr(node, "activation_offload", True)
 
     gm = ColoGraphModule(copy.deepcopy(model), graph)
     gm.recompile()