Fix how max seq len is calculate

Signed-off-by: Vinay Damodaran <[email protected]>

Author: vrdn-23

vllm/model_executor/models/qwen2_5_vl.py

@@ -656,7 +656,7 @@ def compute_attn_mask_seqlen(
         cu_seqlens: torch.Tensor,
     ) -> tuple[Optional[int], Optional[list[int]]]:
         max_seqlen, seqlens = None, None
-        if self.attn_backend == _Backend.FLASH_ATTN:
+        if self.attn_backend in [_Backend.FLASH_ATTN, _Backend.FLASH_ATTN_VLLM_V1]:
             max_seqlen = (cu_seqlens[1:] - cu_seqlens[:-1]).max().item()
         elif self.attn_backend == _Backend.XFORMERS:
             seqlens = (cu_seqlens[1:] - cu_seqlens[:-1]).tolist()

vllm/model_executor/models/qwen2_vl.py

@@ -636,7 +636,7 @@ def compute_attn_mask_seqlen(
             self, cu_seqlens: torch.Tensor
     ) -> tuple[Optional[int], Optional[list[int]]]:
         max_seqlen, seqlens = None, None
-        if self.attn_backend == _Backend.FLASH_ATTN:
+        if self.attn_backend == [_Backend.FLASH_ATTN, _Backend.FLASH_ATTN_VLLM_V1]:
             max_seqlen = (cu_seqlens[1:] - cu_seqlens[:-1]).max().item()
         elif self.attn_backend == _Backend.XFORMERS:
             seqlens = (cu_seqlens[1:] - cu_seqlens[:-1]).tolist()