Use fstr in launcher (#1521)

* Use fstr in launcher

* Fix wrong condition for word_info

* Fix typo

deepspeed/launcher/launch.py

@@ -70,23 +70,21 @@ def main():
 
     for k in current_env.keys():
         if "NCCL" in k:
-            logger.info("%s %s %s", args.node_rank, k, current_env[k])
+            logger.info(f"{args.node_rank} {k}={current_env[k]}")
 
-    world_info = None
-    assert args.world_info != "None", "must provide world info dict"
+    if args.world_info == "None":
+        raise ValueError("world_info can not be None")
     world_info = base64.urlsafe_b64decode(args.world_info)
     world_info = json.loads(world_info)
 
-    logger.info("WORLD INFO DICT: {}".format(world_info))
+    logger.info(f"WORLD INFO DICT: {world_info}")
     node_list = list(world_info.keys())
     args.nnodes = len(node_list)
     local_node = node_list[args.node_rank]
     local_gpu_ids = world_info[local_node]
     num_local_procs = len(local_gpu_ids)
     logger.info(
-        "nnodes={}, num_local_procs={}, node_rank={}".format(args.nnodes,
-                                                             num_local_procs,
-                                                             args.node_rank),
+        f"nnodes={args.nnodes}, num_local_procs={num_local_procs}, node_rank={args.node_rank}"
     )
 
     global_rank_mapping = defaultdict(list)
@@ -98,12 +96,10 @@ def main():
         for gid in gids:
             global_rank_mapping[node_id].append(curr_global_rank)
             curr_global_rank += 1
-    logger.info("global_rank_mapping={}".format(global_rank_mapping))
-    logger.info("dist_world_size={}".format(dist_world_size))
+    logger.info(f"global_rank_mapping={global_rank_mapping}")
+    logger.info(f"dist_world_size={dist_world_size}")
     current_env["CUDA_VISIBLE_DEVICES"] = ",".join(map(str, local_gpu_ids))
-    logger.info("Setting CUDA_VISIBLE_DEVICES={}".format(
-        current_env["CUDA_VISIBLE_DEVICES"]))
-    exclusion_counts_per_node = None
+    logger.info(f"Setting CUDA_VISIBLE_DEVICES={current_env['CUDA_VISIBLE_DEVICES']}")
 
     # set PyTorch distributed related environmental variables
     current_env["MASTER_ADDR"] = args.master_addr
@@ -111,6 +107,7 @@ def main():
     current_env["WORLD_SIZE"] = str(dist_world_size)
 
     processes = []
+    cmd = []
     for local_rank in range(0, num_local_procs):
         # each process's rank
         dist_rank = global_rank_mapping[local_node][local_rank]
@@ -118,36 +115,34 @@ def main():
         current_env["LOCAL_RANK"] = str(local_rank)
 
         # spawn the processes
-        cmd = [
-            sys.executable,
-            "-u",
-            args.training_script,
-            "--local_rank={}".format(local_rank)
-        ] + args.training_script_args
-
-        sig_names = {2: "SIGINT", 15: "SIGTERM"}
-        last_return_code = None
-
-        def sigkill_handler(signum, frame):
-            for process in processes:
-                print(f"Killing subprocess {process.pid}")
-                try:
-                    process.kill()
-                except Exception as e:
-                    pass
-            if last_return_code is not None:
-                raise subprocess.CalledProcessError(returncode=last_return_code, cmd=cmd)
-            if signum in sig_names:
-                print(f"Main process received {sig_names[signum]}, exiting")
-            sys.exit(1)
-
-        # pass SIGINT/SIGTERM to children if the parent is being terminated
-        signal.signal(signal.SIGINT, sigkill_handler)
-        signal.signal(signal.SIGTERM, sigkill_handler)
+        cmd = [sys.executable,
+               "-u",
+               args.training_script,
+               f"--local_rank={local_rank}"] + args.training_script_args
 
         process = subprocess.Popen(cmd, env=current_env)
         processes.append(process)
 
+    sig_names = {2: "SIGINT", 15: "SIGTERM"}
+    last_return_code = None
+
+    def sigkill_handler(signum, frame):
+        for process in processes:
+            logger.info(f"Killing subprocess {process.pid}")
+            try:
+                process.kill()
+            except Exception:
+                pass
+        if last_return_code is not None:
+            raise subprocess.CalledProcessError(returncode=last_return_code, cmd=cmd)
+        if signum in sig_names:
+            logger.info(f"Main process received {sig_names[signum]}, exiting")
+        sys.exit(1)
+
+    # pass SIGINT/SIGTERM to children if the parent is being terminated
+    signal.signal(signal.SIGINT, sigkill_handler)
+    signal.signal(signal.SIGTERM, sigkill_handler)
+
     alive_processes = set(processes)
     while len(alive_processes):
         finished_processes = []
@@ -161,6 +156,7 @@ def main():
                     sigkill_handler(signal.SIGTERM, None)  # not coming back
                 else:
                     # exited cleanly
+                    logger.info(f"Process {process.pid} exits successfully.")
                     finished_processes.append(process)
         alive_processes = set(alive_processes) - set(finished_processes)