Various fixes to run on mps

accelerator/mps_accelerator.py

@@ -26,7 +26,8 @@ def is_synchronized_device(self):
         return False
 
     def use_host_timers(self):
-        return self.is_synchronized_device()
+        # Event timers are not supported on MPS
+        return True
 
     def resolves_data_dependency(self):
         return self.is_synchronized_device()

deepspeed/runtime/engine.py

@@ -457,6 +457,9 @@ def __init__(self,
         self._is_compiled_autograd_enabled = False
         self._compile_kwargs = {}
 
+        if self.dist_backend is None:
+            self.enable_backward_allreduce = False
+
     def _optimized_linear_offload_setup(self):
         self.optimized_linear_base_weight_sharding = False
         self.optimized_linear_lora_enabled = False
@@ -1309,6 +1312,8 @@ def _do_sanity_check(self):
                 f'Client Optimizer (type = {type(self.client_optimizer)} is not instantiated but Client LR Scheduler is instantiated'
 
     def _broadcast_model(self):
+        if self.dist_backend is None:
+            return
 
         def is_replicated(p):
             if hasattr(p, "ds_status") and p.ds_status is not ZeroParamStatus.AVAILABLE: