#2074: Check the phase if needs OfflineLB even if requested in config

src/vt/runtime/runtime.cc

@@ -435,10 +435,10 @@ bool Runtime::needLBDataRestartReader() {
         return ReadLBConfig::hasOfflineLB();
       }
     }
-    return false;
-  } else
+  }
   #endif
-    return false;
+
+  return false;
 }
 
 bool Runtime::initialize(bool const force_now) {

src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc

@@ -150,6 +150,11 @@ LBType LBManager::decideLBToRun(PhaseType phase, bool try_file) {
     }
   }
 
+  // Check if LBDataRestartReader requires to run OfflineLB for a given phase.
+  if(the_lb == LBType::OfflineLB && !theLBDataReader()->needsLB(phase)) {
+    the_lb = LBType::NoLB;
+  }
+
   vt_debug_print(
     terse, lb,
     "LBManager::decidedLBToRun: phase={}, return lb_={}\n",

tests/unit/lb/test_offlinelb.cc

@@ -233,19 +233,19 @@ TEST_F(TestOfflineLB, test_offlinelb_2) {
   std::string file_name = getUniqueFilenameWithRanks(".txt");
   std::ofstream out(file_name);
 
-  // NoLB for phases on skipped list and one phase before them.
-  // Phases on the skipped list: 1, 2, 9
+  // Request OfflineLB for each phase.
+  // LBDataRestartReader will check beforehand if that phase requires OfflineLB.
   out << ""
-    "0 NoLB\n"
-    "1 NoLB\n"
-    "2 NoLB\n"
+    "0 OfflineLB\n"
+    "1 OfflineLB\n"
+    "2 OfflineLB\n"
     "3 OfflineLB\n"
     "4 OfflineLB\n"
     "5 OfflineLB\n"
     "6 OfflineLB\n"
     "7 OfflineLB\n"
-    "8 NoLB\n"
-    "9 NoLB\n";
+    "8 OfflineLB\n"
+    "9 OfflineLB\n";
   out.close();
 
   theConfig()->vt_lb = true;
@@ -261,7 +261,6 @@ TEST_F(TestOfflineLB, test_offlinelb_2) {
     .bulkInsert()
     .wait();
 
-  // Do work for properly configured phases 0-8
   for (PhaseType i = 0; i < num_phases; i++) {
     runInEpochCollective("run sparseHandler", [&]{
       proxy.broadcastCollective<typename SimCol::Msg, &SimCol::sparseHandler>(i);