[TPU] Deprecate `xm.mark_step` in favor of ``torch_xla.sync` (#25254)

Signed-off-by: NickLucche <nlucches@redhat.com>
Co-authored-by: Ye (Charlotte) Qi <yeq@meta.com>

tests/tpu/test_moe_pallas.py

@@ -6,6 +6,7 @@ Run `pytest tests/kernels/moe/test_moe_pallas.py`.
 """
 import pytest
 import torch
+import torch_xla
 
 # yapf conflicts with isort for this block
 # yapf: disable
@@ -77,7 +78,7 @@ def test_pallas_moe(
             expert_map=e_map,
             renormalize=False,
         )
-        xm.mark_step()
+        torch_xla.sync(wait=False)
 
     # Compare outputs
     torch.testing.assert_close(

tests/v1/tpu/test_topk_topp_sampler.py

@@ -4,6 +4,7 @@ import math
 
 import pytest
 import torch
+import torch_xla
 
 from vllm.platforms import current_platform
 from vllm.v1.sample.ops.topk_topp_sampler import apply_top_k_top_p
@@ -63,7 +64,7 @@ def test_topp_result_sums_past_p():
         probs.masked_fill_(logits_masked.isinf(), 0)
         masked_prob_sum = probs.sum(dim=-1)
 
-        xm.mark_step()
+        torch_xla.sync()
 
     # Perform assertion on CPU.
     assert torch.all(torch.ge(masked_prob_sum.cpu() + TOLERANCE, p.cpu()))
@@ -82,7 +83,7 @@ def test_topp_basic():
                                        k=torch.tensor([3, 3]),
                                        p=torch.tensor([0.79, 0.79]))
 
-        xm.mark_step()
+        torch_xla.sync()
 
     # Expect the smallest elements to be dropped.
     expected_result = logits.clone().cpu()
@@ -104,7 +105,7 @@ def test_topp_select_all():
                                        k=torch.tensor([3, 3]),
                                        p=torch.tensor([1.0, 1.0]))
 
-        xm.mark_step()
+        torch_xla.sync()
 
     assert torch.allclose(logits.cpu(), result.cpu())
 
@@ -122,7 +123,7 @@ def test_topp_with_ties():
                                        k=torch.tensor([4]),
                                        p=torch.tensor([0.2]))
 
-        xm.mark_step()
+        torch_xla.sync()
 
     # All tie values are included in the top-p set. Tie breaking is left
     # to be done during final sampling (all tie tokens have equal
@@ -146,7 +147,7 @@ def test_both_topk_topp():
                                        k=torch.tensor([1, 3]),
                                        p=torch.tensor([0.79, 0.79]))
 
-        xm.mark_step()
+        torch_xla.sync()
 
     # Since for the first batch k=1, expect only the largest element gets
     # selected.

vllm/lora/punica_wrapper/punica_tpu.py

@@ -6,7 +6,7 @@ from typing import TYPE_CHECKING, Optional, Union
 
 import torch
 import torch.nn.functional as F
-import torch_xla.core.xla_model as xm
+import torch_xla
 
 from vllm.lora.ops.xla_ops import bgmv_expand, bgmv_expand_slice, bgmv_shrink
 from vllm.lora.punica_wrapper.utils import convert_mapping
@@ -323,7 +323,7 @@ class PunicaWrapperTPU(PunicaWrapperBase):
         extra_vocab_size: int,
     ):
         # Make sure we don't accidentally collect outside operations
-        xm.mark_step()
+        torch_xla.sync()
 
         # Pad the prompt mapping to avoid running into recompiles on the TPU
         # TODO: Should this happen inside mapping internally? If so how can we

vllm/model_executor/model_loader/default_loader.py

@@ -211,16 +211,15 @@ class DefaultModelLoader(BaseModelLoader):
             from vllm.platforms.tpu import USE_TPU_COMMONS
 
             if not USE_TPU_COMMONS:
-                # In PyTorch XLA, we should call `xm.mark_step`
+                # In PyTorch XLA, we should call `torch_xla.sync`
                 # frequently so that not too many ops are accumulated
-                # in the XLA program. import torch_xla.core.xla_model
-                # as xm
-                import torch_xla.core.xla_model as xm
+                # in the XLA program.
+                import torch_xla
 
                 def _xla_weights_iterator(iterator: Generator):
                     for weights in iterator:
                         yield weights
-                        xm.mark_step()
+                        torch_xla.sync(wait=False)
 
                 weights_iterator = _xla_weights_iterator(weights_iterator)
 

vllm/v1/worker/tpu_model_runner.py

@@ -10,6 +10,7 @@ import numpy as np
 import torch
 import torch.nn as nn
 # TPU XLA related
+import torch_xla
 import torch_xla.core.xla_model as xm
 import torch_xla.distributed.spmd as xs
 import torch_xla.runtime as xr
@@ -846,10 +847,10 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
             # 2. A list or tuple (length: num_items) of tensors, each of shape
             # (feature_size, hidden_size) in case the feature size is dynamic
             # depending on the input multimodal items.
-            xm.mark_step()
+            torch_xla.sync(wait=False)
             curr_group_outputs = self.model.get_multimodal_embeddings(
                 **mm_kwargs_group)
-            xm.mark_step()
+            torch_xla.sync(wait=False)
 
             sanity_check_mm_encoder_outputs(
                 curr_group_outputs,
@@ -952,7 +953,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
             mm_embeds = self._gather_mm_embeddings(scheduler_output)
         else:
             mm_embeds = []
-        xm.mark_step()
+        torch_xla.sync(wait=False)
         # Prepare inputs, the requests might be split into multiple
         # executions, combine the result of each execution.
         start_index = 0
@@ -969,7 +970,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                 end_index = self._prepare_inputs(scheduler_output, start_index)
             input_ids, inputs_embeds = self._get_model_inputs(
                 self.input_ids, mm_embeds)
-            xm.mark_step()
+            torch_xla.sync(wait=False)
             # Run the decoder
             with set_forward_context(
                     attn_metadata,
@@ -1183,7 +1184,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
 
         # Sync all pending XLA execution during model initialization and weight
         # loading.
-        xm.mark_step()
+        torch_xla.sync(wait=False)
         xm.wait_device_ops()
         if not hasattr(self, "model"):
             self.model = model
@@ -1267,10 +1268,10 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
 
     def _set_active_loras(self, prompt_lora_mapping, token_lora_mapping,
                           lora_requests) -> None:
-        xm.mark_step()  # Captures input updates
+        torch_xla.sync(wait=False)  # Captures input updates
         super()._set_active_loras(prompt_lora_mapping, token_lora_mapping,
                                   lora_requests)
-        xm.mark_step()  # Captures metadata updates
+        torch_xla.sync(wait=False)  # Captures metadata updates
 
     def _precompile_mm_encoder(self) -> None:
         if not self.supports_mm_inputs:
@@ -1297,10 +1298,10 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                     num_items,
                 )
                 # Run multimodal encoder.
-                xm.mark_step()
+                torch_xla.sync(wait=False)
                 mm_embeds = self.model.get_multimodal_embeddings(
                     **batched_dummy_mm_inputs)
-                xm.mark_step()
+                torch_xla.sync(wait=False)
                 num_patches = mm_embeds[0].shape[0]
                 items_size = num_patches * num_items
 
@@ -1325,7 +1326,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                         a, b = self._get_model_inputs(placeholders_ids,
                                                       [mm_embeds])
                         assert a is None
-                        xm.mark_step()
+                        torch_xla.sync(wait=False)
 
             # Pre-compile `get_input_embeddings` when mm_embeddings are not
             # present. Chunk is only made of text, no mm_placeholders.
@@ -1336,7 +1337,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                 placeholders_ids = placeholders_ids.to(self.device)
                 a, b = self._get_model_inputs(placeholders_ids, [])
                 assert a is None
-                xm.mark_step()
+                torch_xla.sync(wait=False)
 
             xm.wait_device_ops()
             end = time.perf_counter()
@@ -1532,11 +1533,11 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                     # Isolate encoder graph from post-processing to minimize
                     # impact of recompilation until it's fixed.
                     start = time.perf_counter()
-                    xm.mark_step()
+                    torch_xla.sync(wait=False)
                     dummy_encoder_outputs = \
                         self.model.get_multimodal_embeddings(
                         **batched_dummy_mm_inputs)
-                    xm.mark_step()
+                    torch_xla.sync(wait=False)
                     xm.wait_device_ops()
                     end = time.perf_counter()
                     logger.info(
@@ -1559,7 +1560,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
             self._dummy_run(num_tokens, self.num_reqs_most_model_len,
                             self.num_blocks_per_most_len_req)
 
-        xm.mark_step()
+        torch_xla.sync(wait=False)
         xm.wait_device_ops()
         self.encoder_cache.clear()
         gc.collect()
@@ -1927,11 +1928,11 @@ def replace_set_lora(model):
         # to a tensor doesn't seem to work anymore. This might be fixed with a
         # later release of torch_xla.
         self._original_set_lora(index, lora_a, lora_b, embeddings_tensor, bias)
-        xm.mark_step()
+        torch_xla.sync(wait=False)
 
     def _tpu_reset_lora(self, index: int):
         self._original_reset_lora(index)
-        xm.mark_step()
+        torch_xla.sync(wait=False)
 
     for _, module in model.named_modules():
         if isinstance(module, BaseLayerWithLoRA):