add todo

Signed-off-by: yewentao256 <zhyanwentao@126.com>

vllm/v1/attention/backends/mla/flashinfer_mla.py

@@ -131,6 +131,7 @@ class FlashInferMLAImpl(MLACommonImpl[MLACommonMetadata]):
             self.bmm2_scale = layer._v_scale_float
 
         if vllm_is_batch_invariant():
+            # TODO(wentao): optimize this when it is supported by Flashinfer upstream.
             # execute per-request to eliminate batch-shape-dependent kernel paths.
             num = q.shape[0]
             outs = []