[Core] Use `CpuGpuBuffer` for block table tensors (#24795)

Signed-off-by: Nick Hill <nhill@redhat.com>

tests/v1/tpu/worker/test_tpu_model_runner.py

@@ -125,7 +125,7 @@ def _is_req_state_block_table_match(model_runner, req_id: str) -> bool:
         return False
 
     num_blocks = block_table.num_blocks_per_row[req_index]
-    block_table_values = block_table.block_table_np[req_index, :num_blocks]
+    block_table_values = block_table.block_table.np[req_index, :num_blocks]
     return (block_table_values == req_block_ids).all()
 
 

tests/v1/worker/test_gpu_input_batch.py

@@ -15,6 +15,7 @@ from vllm.utils import is_pin_memory_available, make_tensor_with_pad
 from vllm.v1.pool.metadata import PoolingMetadata
 from vllm.v1.sample.logits_processor import LogitsProcessors
 from vllm.v1.sample.metadata import SamplingMetadata
+from vllm.v1.utils import CpuGpuBuffer
 from vllm.v1.worker.block_table import BlockTable, MultiGroupBlockTable
 from vllm.v1.worker.gpu_input_batch import CachedRequestState, InputBatch
 
@@ -45,7 +46,7 @@ def _compare_objs(obj1,
 
         is_same = False
         if isinstance(a, torch.Tensor):
-            if (a.numel() == 0 or b.numel() == 0):
+            if a.numel() == 0 or b.numel() == 0:
                 is_same = (a.numel() == 0 and b.numel() == 0)
             elif torch.allclose(a, b):
                 is_same = True
@@ -61,6 +62,8 @@ def _compare_objs(obj1,
             is_same = True  # if we make it here must be same
         elif a == b:
             is_same = True
+        elif isinstance(a, CpuGpuBuffer):
+            is_same = np.allclose(a.np, b.np) and torch.allclose(a.gpu, b.gpu)
         assert is_same, f"Attribute {attr_name} is different"\
             f" in {obj1} and {obj2}: {a} != {b}"
 

tests/v1/worker/test_gpu_model_runner.py

@@ -165,7 +165,7 @@ def _is_req_state_block_table_match(model_runner, req_id: str) -> bool:
             req_state.block_ids[0]):
         return False
     num_blocks = block_table.num_blocks_per_row[req_index]
-    return (block_table.block_table_np[req_index, :num_blocks] ==
+    return (block_table.block_table.np[req_index, :num_blocks] ==
             req_state.block_ids[0]).all()
 
 

vllm/v1/worker/block_table.py

 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+from typing import Union
 
 import numpy as np
 import torch
@@ -7,6 +8,7 @@ import torch
 from vllm.distributed import get_dcp_group
 from vllm.logger import init_logger
 from vllm.utils import cdiv
+from vllm.v1.utils import CpuGpuBuffer
 
 logger = init_logger(__name__)
 
@@ -29,28 +31,13 @@ class BlockTable:
         self.pin_memory = pin_memory
         self.device = device
 
-        self.block_table = torch.zeros(
-            (max_num_reqs, max_num_blocks_per_req),
-            device=self.device,
-            dtype=torch.int32,
-        )
-        self.block_table_cpu = torch.zeros(
-            (max_num_reqs, max_num_blocks_per_req),
-            device="cpu",
-            dtype=torch.int32,
-            pin_memory=pin_memory,
-        )
-        self.block_table_np = self.block_table_cpu.numpy()
+        self.block_table = self._make_buffer(max_num_reqs,
+                                             max_num_blocks_per_req,
+                                             dtype=torch.int32)
         self.num_blocks_per_row = np.zeros(max_num_reqs, dtype=np.int32)
 
-        self.slot_mapping_cpu = torch.zeros(self.max_num_batched_tokens,
-                                            dtype=torch.int64,
-                                            device="cpu",
-                                            pin_memory=self.pin_memory)
-        self.slot_mapping_np = self.slot_mapping_cpu.numpy()
-        self.slot_mapping = torch.zeros(self.max_num_batched_tokens,
-                                        dtype=torch.int64,
-                                        device=self.device)
+        self.slot_mapping = self._make_buffer(self.max_num_batched_tokens,
+                                              dtype=torch.int64)
         try:
             self.dcp_world_size = get_dcp_group().world_size
             self.dcp_rank = get_dcp_group().rank_in_group
@@ -69,7 +56,7 @@ class BlockTable:
         num_blocks = len(block_ids)
         start = self.num_blocks_per_row[row_idx]
         self.num_blocks_per_row[row_idx] += num_blocks
-        self.block_table_np[row_idx, start:start + num_blocks] = block_ids
+        self.block_table.np[row_idx, start:start + num_blocks] = block_ids
 
     def add_row(self, block_ids: list[int], row_idx: int) -> None:
         self.num_blocks_per_row[row_idx] = 0
@@ -77,17 +64,14 @@ class BlockTable:
 
     def move_row(self, src: int, tgt: int) -> None:
         num_blocks = self.num_blocks_per_row[src]
-        self.block_table_np[tgt, :num_blocks] = self.block_table_np[
-            src, :num_blocks]
+        block_table_np = self.block_table.np
+        block_table_np[tgt, :num_blocks] = block_table_np[src, :num_blocks]
         self.num_blocks_per_row[tgt] = num_blocks
 
     def swap_row(self, src: int, tgt: int) -> None:
-        num_blocks_src = self.num_blocks_per_row[src]
-        num_blocks_tgt = self.num_blocks_per_row[tgt]
-        self.num_blocks_per_row[src] = num_blocks_tgt
-        self.num_blocks_per_row[tgt] = num_blocks_src
-
-        self.block_table_np[[src, tgt]] = self.block_table_np[[tgt, src]]
+        src_tgt, tgt_src = [src, tgt], [tgt, src]
+        self.num_blocks_per_row[src_tgt] = self.num_blocks_per_row[tgt_src]
+        self.block_table.np[src_tgt] = self.block_table.np[tgt_src]
 
     def compute_slot_mapping(self, req_indices: np.ndarray,
                              positions: np.ndarray) -> None:
@@ -107,7 +91,7 @@ class BlockTable:
             virtual_block_size = self.block_size * self.dcp_world_size
             block_table_indices = (req_indices * self.max_num_blocks_per_req +
                                    positions // virtual_block_size)
-            block_numbers = self.block_table_np.ravel()[block_table_indices]
+            block_numbers = self.block_table.np.ravel()[block_table_indices]
             # Use virtual_block_size for mask calculation, which marks local
             # tokens.
             virtual_block_offsets = positions % virtual_block_size
@@ -117,40 +101,45 @@ class BlockTable:
             # Calculate slot_mapping
             slot_mapping = block_numbers * self.block_size + block_offsets
             # Write final slots, use -1 for not-local
-            self.slot_mapping_np[:req_indices.shape[0]] = np.where(
+            self.slot_mapping.np[:req_indices.shape[0]] = np.where(
                 mask, slot_mapping, -1)
         else:
             block_table_indices = (req_indices * self.max_num_blocks_per_req +
                                    positions // self.block_size)
-            block_numbers = self.block_table_np.ravel()[block_table_indices]
+            block_numbers = self.block_table.np.ravel()[block_table_indices]
             block_offsets = positions % self.block_size
             np.add(block_numbers * self.block_size,
                    block_offsets,
-                   out=self.slot_mapping_np[:req_indices.shape[0]])
+                   out=self.slot_mapping.np[:req_indices.shape[0]])
 
     def commit_block_table(self, num_reqs: int) -> None:
-        self.block_table[:num_reqs].copy_(self.block_table_cpu[:num_reqs],
-                                          non_blocking=True)
+        self.block_table.copy_to_gpu(num_reqs)
 
     def commit_slot_mapping(self, num_tokens: int) -> None:
-        self.slot_mapping[:num_tokens].copy_(
-            self.slot_mapping_cpu[:num_tokens], non_blocking=True)
+        self.slot_mapping.copy_to_gpu(num_tokens)
 
     def clear(self) -> None:
-        self.block_table.fill_(0)
-        self.block_table_cpu.fill_(0)
+        self.block_table.gpu.fill_(0)
+        self.block_table.cpu.fill_(0)
 
-    def get_device_tensor(self) -> torch.Tensor:
+    def get_device_tensor(self, num_reqs: int) -> torch.Tensor:
         """Returns the device tensor of the block table."""
-        return self.block_table
+        return self.block_table.gpu[:num_reqs]
 
     def get_cpu_tensor(self) -> torch.Tensor:
         """Returns the CPU tensor of the block table."""
-        return self.block_table_cpu
+        return self.block_table.cpu
 
     def get_numpy_array(self) -> np.ndarray:
         """Returns the numpy array of the block table."""
-        return self.block_table_np
+        return self.block_table.np
+
+    def _make_buffer(self, *size: Union[int, torch.SymInt],
+                     dtype: torch.dtype) -> CpuGpuBuffer:
+        return CpuGpuBuffer(*size,
+                            dtype=dtype,
+                            device=self.device,
+                            pin_memory=self.pin_memory)
 
 
 class MultiGroupBlockTable:

vllm/v1/worker/cpu_model_runner.py

@@ -89,7 +89,7 @@ class CPUModelRunner(GPUModelRunner):
                 assert isinstance(device_tensor, torch.Tensor)
                 setattr(obj, device_attr_name, cpu_tensor)
 
-        for k, v in vars(self).items():
+        for v in vars(self).values():
             if isinstance(v, CpuGpuBuffer):
                 v.gpu = v.cpu
 
@@ -98,9 +98,9 @@ class CPUModelRunner(GPUModelRunner):
                 replace_tensor(self.input_batch, k, k[:-11])
 
         for block_table in self.input_batch.block_table.block_tables:
-            for k, v in vars(block_table).items():
-                if k.endswith("_cpu") and isinstance(v, torch.Tensor):
-                    replace_tensor(block_table, k, k[:-4])
+            for v in vars(block_table).values():
+                if isinstance(v, CpuGpuBuffer):
+                    v.gpu = v.cpu
 
     def load_model(self, eep_scale_up: bool = False) -> None:
         logger.info("Starting to load model %s...", self.model_config.model)

vllm/v1/worker/gpu_model_runner.py

@@ -427,9 +427,6 @@ class GPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                      *size: Union[int, torch.SymInt],
                      dtype: torch.dtype,
                      numpy: bool = True) -> CpuGpuBuffer:
-        # Bfloat16 torch tensors cannot be directly cast to a numpy array, so
-        # if a bfloat16 buffer is needed without a corresponding numpy array,
-        # don't bother instantiating the numpy array.
         return CpuGpuBuffer(*size,
                             dtype=dtype,
                             device=self.device,
@@ -1062,13 +1059,14 @@ class GPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                 num_common_prefix_blocks = 0
             else:
                 blk_table = self.input_batch.block_table[kv_cache_group_id]
-                blk_table_tensor = blk_table.get_device_tensor()[:num_reqs]
-                slot_mapping = blk_table.slot_mapping[:
-                                                      total_num_scheduled_tokens]
+                blk_table_tensor = blk_table.get_device_tensor(num_reqs)
+                slot_mapping = blk_table.slot_mapping.gpu[:
+                                                          total_num_scheduled_tokens]
 
                 # Fill unused with -1. Needed for reshape_and_cache in full cuda
                 # graph mode.
-                blk_table.slot_mapping[total_num_scheduled_tokens:].fill_(-1)
+                blk_table.slot_mapping.gpu[total_num_scheduled_tokens:].fill_(
+                    -1)
                 num_common_prefix_blocks = (
                     scheduler_output.
                     num_common_prefix_blocks[kv_cache_group_id])
@@ -2903,10 +2901,10 @@ class GPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                     num_actual_tokens=num_tokens,
                     max_query_len=max_query_len,
                     max_seq_len=self.max_model_len,
-                    block_table_tensor=self.input_batch.block_table[
-                        kv_cache_group_id].get_device_tensor()[:num_reqs],
-                    slot_mapping=self.input_batch.
-                    block_table[kv_cache_group_id].slot_mapping[:num_tokens],
+                    block_table_tensor=self.input_batch.
+                    block_table[kv_cache_group_id].get_device_tensor(num_reqs),
+                    slot_mapping=self.input_batch.block_table[
+                        kv_cache_group_id].slot_mapping.gpu[:num_tokens],
                     causal=True)
                 for attn_group in self.attn_groups[kv_cache_group_id]:
                     if ubatch_slices is not None:
@@ -3265,8 +3263,8 @@ class GPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                     cudagraph_runtime_mode=cudagraph_runtime_mode,
                     uniform_decode=False)
 
-            # Capture full cudagraph for uniform decode batches if we have
-            # dont already have full mixed prefill-decode cudagraphs
+            # Capture full cudagraph for uniform decode batches if we
+            # don't already have full mixed prefill-decode cudagraphs.
             if cudagraph_mode.decode_mode() == CUDAGraphMode.FULL and \
                 cudagraph_mode.separate_routine():
                 max_num_tokens = self.scheduler_config.max_num_seqs * \