[misc] fix fa patch (#473)

hiyouga · web-flow · commit 2e8e4eee6613 · 2025-08-20T03:21:39.000+08:00
diff --git a/verl/models/transformers/flash_attention_utils.py b/verl/models/transformers/flash_attention_utils.py
@@ -50,7 +50,7 @@ def prepare_fa2_from_position_ids(
     position_ids = position_ids.view(-1)
     cu_seqlens = torch.cat(
         (
-            (position_ids == 0).nonzero().view(-1),
+            (position_ids == 0).nonzero().view(-1).to(torch.int32),
             torch.tensor(position_ids.size(), device=position_ids.device, dtype=torch.int32),
         )
     )

Original file line number	Diff line number	Diff line change
`@@ -50,7 +50,7 @@ def prepare_fa2_from_position_ids(`
`50`	`50`	`position_ids = position_ids.view(-1)`
`51`	`51`	`cu_seqlens = torch.cat(`
`52`	`52`	`(`
`53`		`- (position_ids == 0).nonzero().view(-1),`
	`53`	`+ (position_ids == 0).nonzero().view(-1).to(torch.int32),`
`54`	`54`	`torch.tensor(position_ids.size(), device=position_ids.device, dtype=torch.int32),`
`55`	`55`	`)`
`56`	`56`	`)`