diff --git a/python/llm/src/ipex_llm/transformers/pipeline_parallel.py b/python/llm/src/ipex_llm/transformers/pipeline_parallel.py
index bced1ec9..2e6e99b5 100644
--- a/python/llm/src/ipex_llm/transformers/pipeline_parallel.py
+++ b/python/llm/src/ipex_llm/transformers/pipeline_parallel.py
@@ -462,11 +462,15 @@ class BatchTask(BaseModel):
     partial_prefilling: int
 
 
-def make_attention_mask(prompt_lengths):
+def make_attention_mask(prompt_lengths, device):
     max_length = max(prompt_lengths)
-    attention_mask = torch.zeros((len(prompt_lengths), max_length), dtype=torch.int64)
-    for i, length in enumerate(prompt_lengths):
-        attention_mask[i, max_length - length:] = 1
+    batch_size = len(prompt_lengths)
+
+    range_tensor = torch.arange(max_length, device=device).expand(batch_size, max_length)
+    prompt_lengths_tensor = torch.tensor(prompt_lengths, device=device).unsqueeze(1)
+    attention_mask = range_tensor >= max_length - prompt_lengths_tensor
+    attention_mask = attention_mask.to(torch.int64)
+
     return attention_mask
 
 
@@ -501,6 +505,8 @@ class PPModelWorker:
         self.print_len = {}
         self.is_finish = {}
         self.model_name = checkpoint
+
+        self.device = f"xpu:{self.rank}"
         # self.layer_start = 0
         # self.layer_end = 0
 
@@ -543,7 +549,7 @@ class PPModelWorker:
         return cur_batch
 
     def cat_kv_cache(self, model_type, kv_cache_1, kv_cache_2):
-        if model_type in ["baichuan", "chatglm"]:
+        if model_type in ["baichuan", "chatglm", "mixtral"]:
             result = []
             for sub_tuple1, sub_tuple2 in zip(kv_cache_1, kv_cache_2):
                 if sub_tuple1 is None:
@@ -613,7 +619,7 @@ class PPModelWorker:
         # logger.info(f"{self.rank} {cur_batch} {input.shape}")
         cur_id = cur_batch.batch_id
         _past_key_values = self.past_key_values_dict.get(cur_id, None)
-        attention_mask = make_attention_mask(cur_batch.prompt_lengths).to(input.device)
+        attention_mask = make_attention_mask(cur_batch.prompt_lengths, input.device)
 
         if self.rank == 0:
             input_ids = input
@@ -637,7 +643,7 @@ class PPModelWorker:
                 tmp_past_key_values = _past_key_values
                 _past_key_values = None
 
-        # torch.xpu.empty_cache()
+        torch.xpu.empty_cache()
         output = self.model(input_ids=input_ids,
                             inputs_embeds=inputs_embeds,
                             past_key_values=_past_key_values,
@@ -661,7 +667,7 @@ class PPModelWorker:
 
             if self.pp_config.is_tail:
                 _pre_output = self.partial_output_dict.get(cur_id, None)
-                tmp_output = output.logits.to(self.dtype)
+                tmp_output = output.logits
                 tmp_output = torch.argmax(tmp_output[:, -1:, :], dim=-1)
                 if _pre_output is None:
                     _pre_output = tmp_output
@@ -674,7 +680,10 @@ class PPModelWorker:
             self.past_key_values_dict[cur_id] = _past_key_values
         torch.xpu.synchronize()
         if not self.pp_config.is_tail:
-            return output[0].to(self.dtype), cur_batch
+            _output = output[0]
+            if _output.dtype != self.dtype:
+                _output = _output.to(self.dtype)
+            return _output, cur_batch
         else:
             if cur_batch.partial_prefilling > 0 and \
                cur_batch.prefilled_index == cur_batch.batch_size: