[Cleanup] Remove unused ModelRunner V1 `InputBatch.num_tokens` field (#30218)

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

vllm/v1/worker/gpu_input_batch.py

@@ -128,7 +128,6 @@ class InputBatch:
         # allocation if max_model_len is big.
         # Maps req_index -> tensor of shape (num_prompt_tokens, hidden_size)
         self.req_prompt_embeds: dict[int, torch.Tensor] = {}
-        self.num_tokens = np.zeros(max_num_reqs, dtype=np.int32)
         self.num_tokens_no_spec = np.zeros(max_num_reqs, dtype=np.int32)
         self.num_prompt_tokens = np.zeros(max_num_reqs, dtype=np.int32)
         self.num_computed_tokens_cpu_tensor = torch.zeros(
@@ -340,9 +339,6 @@ class InputBatch:
             self.req_prompt_embeds[req_index] = request.prompt_embeds
         self.token_ids_cpu[req_index, start_idx:end_idx] = request.output_token_ids
         self.is_token_ids[req_index, start_idx:end_idx] = True
-        # Number of token ids in prompt (token_ids_cpu or prompt_embeds).
-        # NOTE(woosuk): This may include spec decode tokens.
-        self.num_tokens[req_index] = request.num_tokens
         # Number of tokens without spec decode tokens.
         self.num_tokens_no_spec[req_index] = request.num_tokens
 
@@ -522,10 +518,6 @@ class InputBatch:
             self.req_id_to_index[old_id_i2],
             self.req_id_to_index[old_id_i1],
         )
-        self.num_tokens[i1], self.num_tokens[i2] = (
-            self.num_tokens[i2],
-            self.num_tokens[i1],
-        )
         self.num_tokens_no_spec[i1], self.num_tokens_no_spec[i2] = (
             self.num_tokens_no_spec[i2],
             self.num_tokens_no_spec[i1],
@@ -661,17 +653,16 @@ class InputBatch:
             self.req_output_token_ids[last_req_index] = None
             self.req_id_to_index[req_id] = empty_index
 
-            if last_req_index != empty_index:
-                (
-                    self.spec_token_ids[last_req_index],
-                    self.spec_token_ids[empty_index],
-                ) = (
-                    self.spec_token_ids[empty_index],
-                    self.spec_token_ids[last_req_index],
-                )
-                self.spec_token_ids[last_req_index].clear()
+            num_tokens = self.num_tokens_no_spec[last_req_index] + len(
+                self.spec_token_ids[last_req_index]
+            )
+
+            (self.spec_token_ids[last_req_index], self.spec_token_ids[empty_index]) = (
+                self.spec_token_ids[empty_index],
+                self.spec_token_ids[last_req_index],
+            )
+            self.spec_token_ids[last_req_index].clear()
 
-            num_tokens = self.num_tokens[last_req_index]
             self.token_ids_cpu[empty_index, :num_tokens] = self.token_ids_cpu[
                 last_req_index, :num_tokens
             ]
@@ -682,7 +673,6 @@ class InputBatch:
                 self.req_prompt_embeds[empty_index] = self.req_prompt_embeds.pop(
                     last_req_index
                 )
-            self.num_tokens[empty_index] = num_tokens
             self.num_tokens_no_spec[empty_index] = self.num_tokens_no_spec[
                 last_req_index
             ]

vllm/v1/worker/gpu_model_runner.py

@@ -923,7 +923,6 @@ class GPUModelRunner(
                         self.input_batch.num_prompt_tokens[req_index]
                         + num_output_tokens
                     )
-                    self.input_batch.num_tokens[req_index] = end_idx
                     self.input_batch.num_tokens_no_spec[req_index] = end_idx
 
             # Update the block IDs.
@@ -968,7 +967,6 @@ class GPUModelRunner(
                     req_index, start_token_index:end_token_index
                 ] = new_token_ids
                 self.input_batch.num_tokens_no_spec[req_index] = end_token_index
-                self.input_batch.num_tokens[req_index] = end_token_index
 
             # Add spec_token_ids to token_ids_cpu.
             spec_token_ids = scheduler_output.scheduled_spec_decode_tokens.get(
@@ -984,8 +982,6 @@ class GPUModelRunner(
                 self.input_batch.token_ids_cpu[
                     req_index, start_index:end_token_index
                 ] = spec_token_ids
-                # NOTE(woosuk): `num_tokens` here may include spec tokens.
-                self.input_batch.num_tokens[req_index] += num_spec_tokens
 
             # When speculative decoding is used with structured output,
             # the scheduler can drop draft tokens that do not
@@ -2702,7 +2698,6 @@ class GPUModelRunner(
             self.input_batch.token_ids_cpu[req_idx, start_idx:end_idx] = sampled_ids
             self.input_batch.is_token_ids[req_idx, start_idx:end_idx] = True
             self.input_batch.num_tokens_no_spec[req_idx] = end_idx
-            self.input_batch.num_tokens[req_idx] = end_idx
 
             req_id = req_ids[req_idx]
             req_state = self.requests[req_id]

vllm/v1/worker/tpu_input_batch.py

@@ -51,7 +51,6 @@ class InputBatch:
             pin_memory=False,
         )
         self.token_ids_cpu = self.token_ids_cpu_tensor.numpy()
-        self.num_tokens = np.zeros(max_num_reqs, dtype=np.int32)
         self.num_tokens_no_spec = np.zeros(max_num_reqs, dtype=np.int32)
         self.num_prompt_tokens = np.zeros(max_num_reqs, dtype=np.int32)
         self.num_computed_tokens_cpu_tensor = torch.zeros(
@@ -200,9 +199,6 @@ class InputBatch:
         start_idx = num_prompt_tokens
         end_idx = start_idx + len(request.output_token_ids)
         self.token_ids_cpu[req_index, start_idx:end_idx] = request.output_token_ids
-        # Number of token ids in token_ids_cpu.
-        # NOTE(woosuk): This may include spec decode tokens.
-        self.num_tokens[req_index] = request.num_tokens
         # Number of tokens without spec decode tokens.
         self.num_tokens_no_spec[req_index] = request.num_tokens
 
@@ -344,10 +340,6 @@ class InputBatch:
             self.req_id_to_index[old_id_i2],
             self.req_id_to_index[old_id_i1],
         )
-        self.num_tokens[i1], self.num_tokens[i2] = (
-            self.num_tokens[i2],
-            self.num_tokens[i1],
-        )
         self.num_tokens_no_spec[i1], self.num_tokens_no_spec[i2] = (
             self.num_tokens_no_spec[i2],
             self.num_tokens_no_spec[i1],
@@ -448,11 +440,10 @@ class InputBatch:
             self.req_output_token_ids[last_req_index] = None
             self.req_id_to_index[req_id] = empty_index
 
-            num_tokens = self.num_tokens[last_req_index]
+            num_tokens = self.num_tokens_no_spec[last_req_index]
             self.token_ids_cpu[empty_index, :num_tokens] = self.token_ids_cpu[
                 last_req_index, :num_tokens
             ]
-            self.num_tokens[empty_index] = num_tokens
             self.num_tokens_no_spec[empty_index] = self.num_tokens_no_spec[
                 last_req_index
             ]

vllm/v1/worker/tpu_model_runner.py

@@ -1283,7 +1283,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
                 token_id = valid_sampled_token_ids[i][0]
                 self.input_batch.token_ids_cpu[i, seq_len] = token_id
                 req_state.output_token_ids.append(token_id)
-                self.input_batch.num_tokens[i] += 1
+                self.input_batch.num_tokens_no_spec[i] += 1
 
         else:
             valid_mask = selected_token_ids != INVALID_TOKEN_ID
@@ -1291,7 +1291,7 @@ class TPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
             valid_sampled_token_ids = [
                 seq.tolist() for seq in selected_token_ids[valid_mask].split(gen_lens)
             ]
-            self.input_batch.num_tokens[:num_reqs] += gen_lens
+            self.input_batch.num_tokens_no_spec[:num_reqs] += gen_lens
             for i, req_state, seq_len in request_seq_lens:
                 target_slice = slice(seq_len - gen_lens[i] + 1, seq_len + 1)
                 self.input_batch.token_ids_cpu[i, target_slice] = (