Keep NVFP4 blockscale swizzle padding on the input device (#39141)

2026-09-11 22:18:02 -07:00
parent c389dd0863
commit dbd4302bbb
1 changed files with 4 additions and 1 deletions
@@ -585,7 +585,10 @@ def swizzle_blockscale(scale: torch.Tensor):
    round_up_multiple = lambda x, m: (x + m - 1) // m * m
    M_padded = round_up_multiple(M, 128)
    K_padded = round_up_multiple(K, 4)
-    padded_scale = torch.zeros((B, M_padded, K_padded), dtype=scale.dtype)
+    # Online weight updates do not necessarily run under a CUDA device context.
+    padded_scale = torch.zeros(
+        (B, M_padded, K_padded), dtype=scale.dtype, device=scale.device
+    )
    padded_scale[:B, :M, :K] = scale
    batches, rows, cols = padded_scale.shape
    assert rows % 128 == 0