Add mean_io timing in disk search cmd output (#607)

Author: suri-kumkaran

apps/search_disk_index.cpp

@@ -179,15 +179,15 @@ int search_disk_index(diskann::Metric &metric, const std::string &index_path_pre
     std::string recall_string = "Recall@" + std::to_string(recall_at);
     diskann::cout << std::setw(6) << "L" << std::setw(12) << "Beamwidth" << std::setw(16) << "QPS" << std::setw(16)
                   << "Mean Latency" << std::setw(16) << "99.9 Latency" << std::setw(16) << "Mean IOs" << std::setw(16)
-                  << "CPU (s)";
+                  << "Mean IO (us)" << std::setw(16) << "CPU (s)";
     if (calc_recall_flag)
     {
         diskann::cout << std::setw(16) << recall_string << std::endl;
     }
     else
         diskann::cout << std::endl;
-    diskann::cout << "==============================================================="
-                     "======================================================="
+    diskann::cout << "=================================================================="
+                     "================================================================="
                   << std::endl;
 
     std::vector<std::vector<uint32_t>> query_result_ids(Lvec.size());
@@ -270,6 +270,9 @@ int search_disk_index(diskann::Metric &metric, const std::string &index_path_pre
         auto mean_cpuus = diskann::get_mean_stats<float>(stats, query_num,
                                                          [](const diskann::QueryStats &stats) { return stats.cpu_us; });
 
+        auto mean_io_us = diskann::get_mean_stats<float>(stats, query_num,
+                                                         [](const diskann::QueryStats &stats) { return stats.io_us; });
+
         double recall = 0;
         if (calc_recall_flag)
         {
@@ -280,7 +283,7 @@ int search_disk_index(diskann::Metric &metric, const std::string &index_path_pre
 
         diskann::cout << std::setw(6) << L << std::setw(12) << optimized_beamwidth << std::setw(16) << qps
                       << std::setw(16) << mean_latency << std::setw(16) << latency_999 << std::setw(16) << mean_ios
-                      << std::setw(16) << mean_cpuus;
+                      << std::setw(16) << mean_io_us << std::setw(16) << mean_cpuus;
         if (calc_recall_flag)
         {
             diskann::cout << std::setw(16) << recall << std::endl;