update default values

Signed-off-by: Youngeun Kwon <youngeunk@nvidia.com>

Author: youngeunkwon0405

nemo_rl/utils/packed_tensor.py

@@ -22,7 +22,7 @@
 
 @lru_cache(maxsize=1)
 def get_target_packed_tensor_size():
-    memory_ratio = os.getenv("NRL_REFIT_BUFFER_MEMORY_RATIO", "0.01")
+    memory_ratio = os.getenv("NRL_REFIT_BUFFER_MEMORY_RATIO", "0.02")
     device = torch.device("cuda")
     props = torch.cuda.get_device_properties(device)
     total_memory_bytes = props.total_memory
@@ -33,7 +33,7 @@ def get_target_packed_tensor_size():
 
 @lru_cache(maxsize=1)
 def get_num_buffers():
-    return int(os.getenv("NRL_REFIT_NUM_BUFFERS", "2"))
+    return int(os.getenv("NRL_REFIT_NUM_BUFFERS", "3"))
 
 
 def packed_broadcast_producer(iterator, group, src, post_iter_func):