From 046d59786531049269395d9be51d258ebeff8a07 Mon Sep 17 00:00:00 2001
From: Nicole Lemaster Slattengren <nlslatt@sandia.gov>
Date: Tue, 9 Apr 2024 11:45:16 -0700
Subject: [PATCH] #2266: lbmanager: print lb time only on rank 0

---
 .../balance/lb_invoke/lb_manager.cc           | 28 +++++++++++--------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc b/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc
index bb43c69666..2de4a94fae 100644
--- a/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc
+++ b/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc
@@ -206,12 +206,14 @@ void LBManager::defaultPostLBWork(ReassignmentMsg* msg) {
 
   auto const start_time = timing::getCurrentTime();
   applyReassignment(reassignment);
-  auto const mig_time = timing::getCurrentTime() - start_time;
-  vt_debug_print(
-    terse, phase,
-    "phase={}: mig_time={}\n",
-    phase, mig_time
-  );
+  if (theContext()->getNode() == 0) {
+    auto const mig_time = timing::getCurrentTime() - start_time;
+    vt_debug_print(
+      terse, phase,
+      "phase={}: mig_time={}\n",
+      phase, mig_time
+    );
+  }
 
   // Inform the collection manager to rebuild spanning trees if needed
   if (reassignment->global_migration_count != 0) {
@@ -270,12 +272,14 @@ LBManager::runLB(PhaseType phase, vt::Callback<ReassignmentMsg> cb) {
     phase, base_proxy, model_.get(), stats, *comm, total_load_from_model,
     *data_map
   );
-  auto const lb_time = timing::getCurrentTime() - start_time;
-  vt_debug_print(
-    terse, phase,
-    "phase={}: lb_time={}\n",
-    phase, lb_time
-  );
+  if (theContext()->getNode() == 0) {
+    auto const lb_time = timing::getCurrentTime() - start_time;
+    vt_debug_print(
+      terse, phase,
+      "phase={}: lb_time={}\n",
+      phase, lb_time
+    );
+  }
   cb.send(reassignment, phase);
 }