[Perf] Cache uniform ragged-verify layout for DSpark verify-all compact (#31434)

python/sglang/srt/speculative/dspark_components/dspark_planner.py

@@ -124,6 +124,7 @@ class DSparkVerifyPlanner:
         self._dynamic_graph_tier = False
         self._dp_tier_gather_enabled = False
         self._is_verify_all = True
+        self._uniform_layout_cache: dict = {}
         if self._ragged_verify_mode is not RaggedVerifyMode.STATIC:
             if self._confidence_head is None:
                 raise ValueError(
@@ -417,6 +418,21 @@ class DSparkVerifyPlanner:
     ) -> Optional[RaggedVerifyLayout]:
         if self._ragged_verify_mode is RaggedVerifyMode.STATIC:
             return None
+        if self._is_verify_all and self._ragged_verify_mode is RaggedVerifyMode.COMPACT:
+            # Verify-all: the uniform layout (or None, past the captured grid)
+            # is constant per (bs, tier); serve it from cache instead of paying
+            # the per-step schedule and its host<->device round-trips.
+            key = (int(req_pool_indices.shape[0]), global_num_reqs)
+            if key not in self._uniform_layout_cache:
+                self._uniform_layout_cache[key] = uniform_ragged_layout(
+                    bs=key[0],
+                    device=device,
+                    verify_num_draft_tokens=self.verify_num_draft_tokens,
+                    ragged_verify_mode=self._ragged_verify_mode,
+                    model_runner=self.model_runner,
+                    tier_num_reqs=global_num_reqs,
+                )
+            return self._uniform_layout_cache[key]
         verify_lens = self._schedule_verify_lens(
             req_pool_indices=req_pool_indices,
             prefix_lens=prefix_lens,