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A high-throughput and memory-efficient inference and serving engine for LLMs

Mirrored from https://github.com/tduncan-lum/Nvidia-Optimization-Stack---VLLM.git

Synced Nov 8, 21:30 UTC

Revert "[Attention][FA3] Update FA3 to include new swizzle optimization" (#33841)

Luka Govedič committed Feb 4, 2026 at 22:54 UTC e3bf79ffa080a5052aa61fce71b70b11fb7f9d1e
3 files changed +3 -13
cmake/external_projects/vllm_flash_attn.cmake
+1 -1
@@ -38,7 +38,7 @@ else()
38 FetchContent_Declare(
39 vllm-flash-attn
40 GIT_REPOSITORY https://github.com/vllm-project/flash-attention.git
41 - GIT_TAG 2adfc8c2177c5b0e8ddeedfd5a8990d80eb496ff
41 + GIT_TAG 188be16520ceefdc625fdf71365585d2ee348fe2
42 GIT_PROGRESS TRUE
43 # Don't share the vllm-flash-attn build between build types
44 BINARY_DIR ${CMAKE_BINARY_DIR}/vllm-flash-attn
vllm/v1/attention/backends/flash_attn.py
+1 -6
@@ -308,15 +308,10 @@ class FlashAttentionMetadataBuilder(AttentionMetadataBuilder[FlashAttentionMetad
308 self.compilation_config.cudagraph_mode.has_full_cudagraphs()
309 )
310 self.max_cudagraph_size = self.compilation_config.max_cudagraph_capture_size
311 - max_num_seqs = vllm_config.scheduler_config.max_num_seqs
311
312 if self.use_full_cuda_graph and self.aot_schedule:
314 - # Times 4 due to:
315 - # https://github.com/vllm-project/flash-attention/blob/3223650ccabe622a0fcae65eec706a50186a89f7/hopper/flash_api.cpp#L650-L653
316 - # For some tests max_cudagraph_size > max_num_seqs,
317 - # so we need to use the larger one.
313 self.scheduler_metadata = torch.zeros(
319 - max(self.max_cudagraph_size or 0, max_num_seqs) * 4 + 1,
314 + vllm_config.scheduler_config.max_num_seqs + 1,
315 dtype=torch.int32,
316 device=self.device,
317 )
vllm/v1/attention/backends/mla/flashattn_mla.py
+1 -6
@@ -127,15 +127,10 @@ class FlashAttnMLAMetadataBuilder(MLACommonMetadataBuilder[FlashAttnMLAMetadata]
127 self.compilation_config.cudagraph_mode.has_full_cudagraphs()
128 )
129 self.max_cudagraph_size = self.compilation_config.max_cudagraph_capture_size
130 - max_num_seqs = vllm_config.scheduler_config.max_num_seqs
130
131 if self.use_full_cuda_graph and self.fa_aot_schedule:
133 - # Times 4 due to:
134 - # https://github.com/vllm-project/flash-attention/blob/3223650ccabe622a0fcae65eec706a50186a89f7/hopper/flash_api.cpp#L650-L653
135 - # For some tests max_cudagraph_size > max_num_seqs,
136 - # so we need to use the larger one.
132 self.scheduler_metadata = torch.zeros(
138 - max(self.max_cudagraph_size or 0, max_num_seqs) * 4 + 1,
133 + vllm_config.scheduler_config.max_num_seqs + 1,
134 dtype=torch.int32,
135 device=self.device,
136 )