Scale kkt after reduction (#10604)

python/sglang/srt/layers/attention/fla/chunk_scaled_dot_kkt.py

@@ -74,8 +74,7 @@ def chunk_scaled_dot_kkt_fwd_kernel(
             (1, 0),
         )
         b_k = tl.load(p_k, boundary_check=(0, 1))
-        b_kb = b_k * b_beta[:, None]
-        b_A += tl.dot(b_kb.to(b_k.dtype), tl.trans(b_k))
+        b_A += tl.dot(b_k, tl.trans(b_k))
 
     if USE_G:
         p_g = tl.make_block_ptr(
@@ -85,6 +84,7 @@ def chunk_scaled_dot_kkt_fwd_kernel(
         b_g_diff = b_g[:, None] - b_g[None, :]
         b_A = b_A * safe_exp(b_g_diff)
 
+    b_A *= b_beta[:, None]
     b_A = tl.where(o_t[:, None] > o_t[None, :], b_A, 0)
     p_A = tl.make_block_ptr(
         A + (bos * H + i_h) * BT, (T, BT), (BT * H, 1), (i_t * BT, 0), (BT, BT), (1, 0)