[Bugfix] Make dummy encoder prompt padding alternative and add missing warnings (#16129)

Signed-off-by: Isotr0py <2037008807@qq.com>

tests/models/multimodal/processing/test_mllama.py

+# SPDX-License-Identifier: Apache-2.0
+"""Tests for mllama's multimodal preprocessing and profiling."""
+import pytest
+from transformers import MllamaConfig
+
+from vllm.multimodal import MULTIMODAL_REGISTRY
+from vllm.multimodal.profiling import MultiModalProfiler
+
+from ...utils import build_model_context
+
+
+@pytest.mark.parametrize("model_id",
+                         ["meta-llama/Llama-3.2-11B-Vision-Instruct"])
+@pytest.mark.parametrize("max_model_len", [4096, 8192, 25600, 131072])
+@pytest.mark.parametrize("max_num_seqs", [1, 2, 8])
+def test_profiling(
+    model_id: str,
+    max_model_len: int,
+    max_num_seqs: int,
+):
+    # regression test for https://github.com/vllm-project/vllm/issues/13929
+    from vllm.model_executor.models.mllama import calc_token_per_chunk
+
+    model_config_kwargs = {
+        "max_model_len": max_model_len,
+    }
+    ctx = build_model_context(
+        model_id,
+        model_config_kwargs=model_config_kwargs,
+        limit_mm_per_prompt={"image": 1},
+    )
+
+    mm_config = ctx.get_mm_config()
+    processor = MULTIMODAL_REGISTRY.create_processor(ctx.model_config)
+    profiler = MultiModalProfiler(processor)
+
+    dummy_encoder_data = profiler.get_encoder_dummy_data(
+        max_model_len,
+        mm_counts=mm_config.limit_per_prompt,
+    )
+    dummy_mm_data = processor.dummy_inputs.get_dummy_processor_inputs(
+        max_model_len,
+        mm_counts=mm_config.limit_per_prompt,
+    )
+
+    hf_config = ctx.get_hf_config(MllamaConfig)
+    image_size = hf_config.vision_config.image_size
+    encoder_seq_lens = [len(dummy_encoder_data.prompt_token_ids)
+                        ] * max_num_seqs
+
+    mm_kwargs = processor.apply(
+        prompt=dummy_mm_data.prompt_text,
+        mm_data=dummy_mm_data.mm_data,
+        hf_processor_mm_kwargs=dict(),
+    )["mm_kwargs"]
+
+    # Get the actual number of encoder tokens for each sample.
+    # Because attn_metadata.encoder_seq_lens only counts the last
+    # group of images for each sample, which is used to cheat the
+    # block manager to allocate blocks for those images only.
+    # See MllamaMultiModalProcessor for more details.
+    num_tiles = [[t] for t in mm_kwargs.pop("num_tiles")]
+    num_tokens_per_tile = calc_token_per_chunk(image_size)
+    actual_encoder_seq_lens = [
+        sum(num_tile) * num_tokens_per_tile for num_tile in num_tiles
+    ]
+
+    # simulate mllama image-present prefill.
+    for actual_len, last_group_len in zip(actual_encoder_seq_lens,
+                                          encoder_seq_lens):
+        assert actual_len >= last_group_len

tests/models/utils.py

@@ -255,6 +255,7 @@ def build_model_context(
     model_id: str,
     task: TaskOption = "auto",
     dtype: Union[str, torch.dtype] = "auto",
+    model_config_kwargs: Optional[dict[str, Any]] = None,
     mm_processor_kwargs: Optional[dict[str, Any]] = None,
     limit_mm_per_prompt: Optional[dict[str, int]] = None,
     disable_mm_preprocessor_cache: bool = True,
@@ -274,6 +275,7 @@ def build_model_context(
     model_info.check_available_online(on_fail="skip")
     model_info.check_transformers_version(on_fail="skip")
 
+    model_config_kwargs = model_config_kwargs or {}
     model_config = ModelConfig(
         model_id,
         task=task,
@@ -286,5 +288,6 @@ def build_model_context(
         limit_mm_per_prompt=limit_mm_per_prompt,
         disable_mm_preprocessor_cache=disable_mm_preprocessor_cache,
         hf_overrides=model_info.hf_overrides,
+        **model_config_kwargs,
     )
     return InputContext(model_config)

vllm/model_executor/models/whisper.py

@@ -580,6 +580,10 @@ class WhisperMultiModalProcessor(
         feature_extractor = self.info.get_feature_extractor()
         return MultiModalDataParser(target_sr=feature_extractor.sampling_rate)
 
+    @property
+    def pad_dummy_encoder_prompt(self) -> bool:
+        return True
+
     def create_encoder_prompt(
         self,
         prompt: Union[str, list[int]],

vllm/multimodal/processing.py

@@ -1654,6 +1654,10 @@ class EncDecMultiModalProcessor(BaseMultiModalProcessor[_I]):
         """
         raise NotImplementedError
 
+    @property
+    def pad_dummy_encoder_prompt(self) -> bool:
+        return False
+
     def create_decoder_prompt(
         self,
         prompt: Union[str, list[int]],

vllm/multimodal/profiling.py

@@ -15,7 +15,8 @@ from vllm.logger import init_logger
 from .inputs import (MultiModalDataDict, MultiModalEncDecInputs,
                      MultiModalInputs, MultiModalKwargs,
                      MultiModalPlaceholderDict)
-from .processing import BaseMultiModalProcessor, BaseProcessingInfo
+from .processing import (BaseMultiModalProcessor, BaseProcessingInfo,
+                         EncDecMultiModalProcessor)
 
 logger = init_logger(__name__)
 
@@ -200,7 +201,10 @@ class MultiModalProfiler(Generic[_I]):
         seq_len: int,
         mm_counts: Optional[Mapping[str, int]] = None,
     ) -> DummyEncoderData:
-        mm_inputs, _ = self.get_and_validate_mm_inputs(seq_len, mm_counts)
+        (
+            mm_inputs,
+            total_placeholders_by_modality,
+        ) = self.get_and_validate_mm_inputs(seq_len, mm_counts)
         mm_inputs = cast(MultiModalEncDecInputs, mm_inputs)
 
         # For encoder-decoder models, use encoder prompt token ids instead of
@@ -208,8 +212,26 @@ class MultiModalProfiler(Generic[_I]):
         encoder_prompt_token_ids = mm_inputs["encoder_prompt_token_ids"]
 
         total_len = len(encoder_prompt_token_ids)
-        num_tokens_to_pad = max(total_len, seq_len) - total_len
-        encoder_prompt_token_ids.extend([0] * num_tokens_to_pad)
+
+        # Encoder-decoder multimodal models only support v0
+        if total_len > seq_len:
+            # `max_num_batched_tokens` is defined by `SchedulerConfig`
+            logger.warning(
+                "The encoder sequence length used for profiling ("
+                "max_num_batched_tokens / max_num_seqs = %d) is too short "
+                "to hold the multi-modal embeddings in the worst case "
+                "(%d tokens in total, out of which %s are reserved for "
+                "multi-modal embeddings). This may cause certain "
+                "multi-modal inputs to fail during inference, even when "
+                "the input text is short. To avoid this, you should "
+                "increase `max_model_len`, reduce `max_num_seqs`, "
+                "and/or reduce `mm_counts`.", seq_len, total_len,
+                total_placeholders_by_modality)
+
+        processor = cast(EncDecMultiModalProcessor, self.processor)
+        if processor.pad_dummy_encoder_prompt:
+            num_tokens_to_pad = max(total_len, seq_len) - total_len
+            encoder_prompt_token_ids.extend([0] * num_tokens_to_pad)
 
         return DummyEncoderData(encoder_prompt_token_ids)