Add simulated perfect timing vcycle

Author: T3C42

mt-kahypar/dynamic/strategies/localFM_rebalance_vcycle.h

@@ -468,7 +468,7 @@ namespace mt_kahypar::dyn {
         local_fm(local_fm_nodes, gain_cache_nodes, change, empty_blocks);
         ASSERT(context.dynamic.incremental_km1 == metrics::quality(partitioned_hypergraph_m, Objective::km1), context.dynamic.incremental_km1 << " vs. " << metrics::quality(partitioned_hypergraph_m, Objective::km1));
 
-          if (changed_weight > context.dynamic.vcycle_step_size_pct * prior_total_weight && change_count <= changes_size * (static_cast<float>(context.dynamic.stop_vcycle_at_pct) / 100)) {
+          if ((changed_weight > context.dynamic.vcycle_step_size_pct * prior_total_weight && change_count <= changes_size * (static_cast<float>(context.dynamic.stop_vcycle_at_pct) / 100)) || context.dynamic.simulate_opt_vcycle && change_count == changes_size) {
             std::cout << "Starting v-cycle " << change_count << "/" << changes_size << " after processing " << changed_weight << " weight changes (" << (100.0 * changed_weight / prior_total_weight) << "% of total weight)" << std::endl;
 
             HighResClockTimepoint vcycle_start = std::chrono::high_resolution_clock::now();

mt-kahypar/io/command_line_options.cpp

@@ -887,6 +887,10 @@ namespace mt_kahypar {
       ("d-stream-changes",
         po::value<bool>(&context.dynamic.stream_changes)->value_name("<bool>"),
         "If true, then the partitioner is started in streaming mode, which means that it processes changes one by one and does not store them in memory.");
+      dynamic_options.add_options()
+      ("d-simulate-opt-vcycle",
+        po::value<bool>(&context.dynamic.simulate_opt_vcycle)->value_name("<bool>"),
+        "If true, then the partitioner simulates an optimal v-cycle by triggering a vcycle at the very last change.");
     return dynamic_options;
   }
 

mt-kahypar/partition/context.h

@@ -317,6 +317,7 @@ struct DynamicParameters {
   size_t small_blocks_threshold = 5;
   bool stream_changes = false; // if true, changes are read and processed one by one, otherwise all changes are read in memory and then processed
   bool lazy_pull_updates = true; // ignore updates for the rebalancer that decrement gain
+  bool simulate_opt_vcycle = false;
 
   // not a parameter
   std::string output_path = "";