SFC load balance: add background loads for a more even distribution o…

…f chares. Also a little cleanup of MultistepLB_notopo.
N-BodyShop · Jul 23, 2024 · 1edd4c7 · 1edd4c7
1 parent ec82526
commit 1edd4c7
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Showing 3 changed files with 17 additions and 7 deletions.
diff --git a/MultistepLB_SFC.cpp b/MultistepLB_SFC.cpp
@@ -129,6 +129,12 @@ void MultistepLB_SFC::work2(BaseLB::LDStats *stats){
 
     int numProcessed = 0;
 
+    double dBgLoad = 0.0;
+    for(int i = 0; i < stats->nprocs(); i++){
+        dBgLoad += stats->procs[i].bg_walltime;
+    }
+    dBgLoad /= numobjs;
+
     dTotalLoad = 0.0;
     for(int i = 0; i < numobjs; i++){
         if(!stats->objData[i].migratable) continue;
@@ -140,14 +146,20 @@ void MultistepLB_SFC::work2(BaseLB::LDStats *stats){
             load = udata->myNumParticles;
         }
         else{
-            load = stats->objData[i].wallTime;
+            // give each piece a portion of the background load
+            load = stats->objData[i].wallTime + dBgLoad;
         }
 
         tp_array[numProcessed] = SFCObject(i, load);
         tp_array[numProcessed].centroid = udata->vec;
         numProcessed++;
         dTotalLoad += load;
     }
+
+    if(verbosity > 0)
+        CkPrintf("Avg active load %g; Avg bg load %g\n", dTotalLoad/numobjs,
+                 dBgLoad);
+
     CkAssert(numProcessed==nmig);
 
     sfcPrepare(tp_array, nmig, stats);

diff --git a/MultistepLB_notopo.cpp b/MultistepLB_notopo.cpp
@@ -45,7 +45,7 @@ bool MultistepLB_notopo::QueryBalanceNow(int step){
 }
 
 // helper functions for multistepping
-#ifdef MCLBMS
+#ifdef MCLBMSV
 
 void MultistepLB_notopo::makeActiveProcessorList(BaseLB::LDStats *stats, int numActiveObjs){
   int objsPerProc = 8;
@@ -54,9 +54,7 @@ void MultistepLB_notopo::makeActiveProcessorList(BaseLB::LDStats *stats, int num
   procsNeeded = expandFactor*numActiveObjs/objsPerProc > stats->nprocs() ? stats->nprocs() : expandFactor*numActiveObjs/objsPerProc;
 
   /* currently, only the first procsNeeded procs are used - could do something more sophisticated here in the future - FIXME */
-#ifdef MCLBMSV
   CkPrintf("Processors 0 to %d active\n", procsNeeded-1);
-#endif
 }
 #endif
 
@@ -129,10 +127,9 @@ void MultistepLB_notopo::work(BaseLB::LDStats* stats)
 
   // select processors
 #ifdef MCLBMSV
-  //printData(*stats, phase, NULL);
   CkPrintf("making active processor list\n");
-#endif
   makeActiveProcessorList(stats, numActiveObjects);
+#endif
   count = stats->nprocs();
 
   // let the strategy take over on this modified instrumented data and processor information

diff --git a/MultistepLB_notopo.h b/MultistepLB_notopo.h
@@ -35,8 +35,9 @@ class MultistepLB_notopo : public CBase_MultistepLB_notopo, public Orb3dCommon {
 private:
   void init();
   bool QueryBalanceNow(int step);
+#ifdef MCLBMSV
   void makeActiveProcessorList(BaseLB::LDStats *stats, int numActiveObjs);
-
+#endif
 
 public:
   MultistepLB_notopo(const CkLBOptions &);