diff --git a/cpp/src/scheduler/task/SearchTask.cpp b/cpp/src/scheduler/task/SearchTask.cpp
index 8d76075014984902992cddfa5663ecfdda966be4..59f6509c02bebf22a02d6f72ae2426d577740bba 100644
--- a/cpp/src/scheduler/task/SearchTask.cpp
+++ b/cpp/src/scheduler/task/SearchTask.cpp
@@ -163,32 +163,37 @@ XSearchTask::Execute() {
     std::vector<float> output_distance;
     for (auto &context : search_contexts_) {
         //step 1: allocate memory
-        auto inner_k = context->topk();
-        auto nprobe = context->nprobe();
-        output_ids.resize(inner_k * context->nq());
-        output_distance.resize(inner_k * context->nq());
+        uint64_t nq = context->nq();
+        uint64_t topk = context->topk();
+        uint64_t nprobe = context->nprobe();
+        const float* vectors = context->vectors();
+
+        output_ids.resize(topk * nq);
+        output_distance.resize(topk * nq);
+        std::string hdr = "context " + context->Identity() +
+            " nq " + std::to_string(nq) +
+            " topk " + std::to_string(topk);
 
         try {
             //step 2: search
-            index_engine_->Search(context->nq(), context->vectors(), inner_k, nprobe, output_distance.data(),
-                                  output_ids.data());
+            index_engine_->Search(nq, vectors, topk, nprobe, output_distance.data(), output_ids.data());
 
-            double span = rc.RecordSection("do search for context:" + context->Identity());
+            double span = rc.RecordSection(hdr + ", do search");
             context->AccumSearchCost(span);
 
 
             //step 3: cluster result
             SearchContext::ResultSet result_set;
-            auto spec_k = index_engine_->Count() < context->topk() ? index_engine_->Count() : context->topk();
-            XSearchTask::ClusterResult(output_ids, output_distance, context->nq(), spec_k, result_set);
+            auto spec_k = index_engine_->Count() < topk ? index_engine_->Count() : topk;
+            XSearchTask::ClusterResult(output_ids, output_distance, nq, spec_k, result_set);
 
-            span = rc.RecordSection("cluster result for context:" + context->Identity());
+            span = rc.RecordSection(hdr + ", cluster result");
             context->AccumReduceCost(span);
 
             // step 4: pick up topk result
-            XSearchTask::TopkResult(result_set, inner_k, metric_l2, context->GetResult());
+            XSearchTask::TopkResult(result_set, topk, metric_l2, context->GetResult());
 
-            span = rc.RecordSection("reduce topk for context:" + context->Identity());
+            span = rc.RecordSection(hdr + ", reduce topk");
             context->AccumReduceCost(span);
         } catch (std::exception &ex) {
             ENGINE_LOG_ERROR << "SearchTask encounter exception: " << ex.what();