Enable overlap scheduler by default for the triton attention backend (#2105)

python/sglang/srt/layers/attention/triton_backend.py

@@ -53,7 +53,7 @@ class TritonAttnBackend(AttentionBackend):
             start_loc = torch.zeros_like(forward_batch.seq_lens, dtype=torch.int32)
             start_loc[1:] = torch.cumsum(forward_batch.seq_lens[:-1], dim=0)
 
-            total_num_tokens = torch.sum(forward_batch.seq_lens).item()
+            total_num_tokens = forward_batch.seq_lens_sum
             attn_logits = torch.empty(
                 (self.num_head, total_num_tokens),
                 dtype=self.reduce_dtype,

python/sglang/srt/managers/scheduler.py

@@ -170,18 +170,9 @@ class Scheduler:
         if not self.is_generation:
             self.enable_overlap = False
             logger.info("Overlap scheduler is disabled for embedding models.")
-        if (
+
-            server_args.attention_backend == "triton"
+        if self.enable_overlap:
-            or server_args.enable_double_sparsity
+            self.disable_jump_forward = True
-            or (
-                self.model_config.attention_arch == AttentionArch.MLA
-                and not self.server_args.disable_mla
-            )
-        ):
-            self.enable_overlap = False
-            logger.info(
-                "Overlap scheduler is disabled if using triton attention backend."
-            )
 
         # Launch a tensor parallel worker
         if self.enable_overlap:

python/sglang/srt/managers/tp_worker_overlap_thread.py

@@ -94,10 +94,21 @@ class TpModelWorkerClient:
 
     @torch.no_grad()
     def forward_thread_func_(self):
+        batch_pt = 0
+        batch_lists = [None] * 2
+
         while True:
             model_worker_batch, future_token_ids_ct = self.input_queue.get()
             if not model_worker_batch:
                 break
+
+            # Keep a reference of model_worker_batch by storing it into a list.
+            # Otherwise, the tensor members of model_worker_batch will be released
+            # by pytorch and cause CUDA illegal memory access errors.
+            batch_lists[batch_pt % 2] = model_worker_batch
+            batch_pt += 1
+
+            # Create event
             self.launch_done = threading.Event()
             copy_done = torch.cuda.Event()
 

python/sglang/srt/model_executor/cuda_graph_runner.py

@@ -170,7 +170,6 @@ class CudaGraphRunner:
                 self.encoder_lens = None
 
             if self.enable_dp_attention:
-                self.global_num_tokens = [0] * self.tp_size
                 self.gathered_buffer = torch.zeros(
                     (
                         self.max_bs * self.tp_size,
@@ -264,10 +263,10 @@ class CudaGraphRunner:
         mrope_positions = self.mrope_positions[:, :bs]
 
         if self.enable_dp_attention:
-            self.global_num_tokens[:] = [bs] * self.tp_size
+            global_num_tokens = [bs] * self.tp_size
             gathered_buffer = self.gathered_buffer[: bs * self.tp_size]
         else:
-            self.global_num_tokens = None
+            global_num_tokens = None
             gathered_buffer = None
 
         # Attention backend
@@ -296,7 +295,7 @@ class CudaGraphRunner:
                 top_logprobs_nums=[0] * bs,
                 positions=clamp_position(seq_lens),
                 mrope_positions=mrope_positions,
-                global_num_tokens=self.global_num_tokens,
+                global_num_tokens=global_num_tokens,
                 gathered_buffer=gathered_buffer,
             )
             logits_output = forward(input_ids, forward_batch.positions, forward_batch)
@@ -348,8 +347,6 @@ class CudaGraphRunner:
             self.encoder_lens[:raw_bs].copy_(forward_batch.encoder_lens)
         if forward_batch.mrope_positions is not None:
             self.mrope_positions[:, :raw_bs].copy_(forward_batch.mrope_positions)
-        if self.enable_dp_attention:
-            self.global_num_tokens[:] = [bs] * self.tp_size
 
         # Attention backend
         self.model_runner.attn_backend.init_forward_metadata_replay_cuda_graph(

python/sglang/srt/server_args.py

@@ -174,17 +174,17 @@ class ServerArgs:
             self.cuda_graph_max_bs = 4
             logger.info("Automatically adjust --chunked-prefill-size for small GPUs.")
 
+        # Choose kernel backends
         if not is_flashinfer_available():
             self.attention_backend = "triton"
             self.sampling_backend = "pytorch"
 
-        # Default kernel backends
         if self.attention_backend is None:
             self.attention_backend = "flashinfer"
-
         if self.sampling_backend is None:
             self.sampling_backend = "flashinfer"
 
+        # Others
         if self.enable_dp_attention:
             self.dp_size = self.tp_size
             self.chunked_prefill_size = self.chunked_prefill_size // 2
@@ -205,9 +205,6 @@ class ServerArgs:
             )
             self.disable_overlap_schedule = True
 
-        if not self.disable_overlap_schedule:
-            self.disable_jump_forward = True
-
     @staticmethod
     def add_cli_args(parser: argparse.ArgumentParser):
         # Model and port args

scripts/killall_sglang.sh

@@ -2,3 +2,4 @@
 
 kill -9 $(ps aux | grep 'multiprocessing.spawn' | grep -v 'grep' | awk '{print $2}')
 kill -9 $(ps aux | grep 'sglang.launch_server' | grep -v 'grep' | awk '{print $2}')
+kill -9 $(ps aux | grep 'sglang.bench' | grep -v 'grep' | awk '{print $2}')