From 2acdda1d850122129c6ff21b6d07b2a4c9eb31bd Mon Sep 17 00:00:00 2001 From: Mohammad Miadh Angkad <176301910+mmangkad@users.noreply.github.com> Date: Mon, 30 Mar 2026 03:30:40 +0800 Subject: [PATCH] [Fix] Remove redundant allreduce fusion block and skip TP=1 (#20621) --- python/sglang/srt/server_args.py | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/python/sglang/srt/server_args.py b/python/sglang/srt/server_args.py index 92e524a6b..04a365927 100644 --- a/python/sglang/srt/server_args.py +++ b/python/sglang/srt/server_args.py @@ -1706,13 +1706,6 @@ class ServerArgs: quant_method = get_quantization_config(hf_config) is_mxfp4_quant_format = quant_method == "mxfp4" - if is_blackwell_supported(): - # workaround for https://github.com/flashinfer-ai/flashinfer/issues/2006 - if not self.enable_dp_attention and self.nnodes == 1: - self.enable_flashinfer_allreduce_fusion = True - logger.info( - "Enable FlashInfer AllReduce Fusion on sm100 for GptOssForCausalLM" - ) if not self.enable_dp_attention and self.nnodes == 1 and is_hip(): # TODO (Hubert): Put this back later # self.enable_aiter_allreduce_fusion = True @@ -2076,6 +2069,7 @@ class ServerArgs: "Qwen3_5ForConditionalGeneration", ] and (is_sm90_supported() or is_sm100_supported()) + and self.tp_size > 1 and not self.enable_dp_attention and self.attn_cp_size <= 1 and self.nnodes == 1 @@ -2083,6 +2077,9 @@ class ServerArgs: and self.moe_a2a_backend == "none" ): self.enable_flashinfer_allreduce_fusion = True + logger.info( + f"Auto-enabling FlashInfer AllReduce Fusion on SM90/SM10X for {model_arch}" + ) def _handle_mamba_radix_cache( self,