Merge pull request #47729 from hqucms/xpog/fix-merge-mem

Reduce memory usage in NANO merge jobs

Author: cmsbuild

PhysicsTools/NanoAOD/plugins/NanoAODOutputModule.cc

@@ -273,7 +273,7 @@ void NanoAODOutputModule::writeRun(edm::RunForOutput const& iRun) {
         throw cms::Exception("LogicError", "Inconsistent nanoMetadata " + p.first + " (" + hstring->str() + ")");
     } else {
       auto ostr = std::make_unique<TObjString>(hstring->str().c_str());
-      m_file->WriteTObject(ostr.release(), p.first.c_str());
+      m_file->WriteTObject(ostr.get(), p.first.c_str());
     }
   }
 

PhysicsTools/NanoAOD/plugins/SummaryTableOutputBranches.cc

@@ -10,7 +10,7 @@ void SummaryTableOutputBranches::makeScalarBranches(const std::vector<Col> &tabc
           return x.name == col.name;
         }) == branches.end()) {
       T backFillValue = 0;
-      auto *br = tree.Branch(col.name.c_str(), &backFillValue, (col.name + "/" + rootType).c_str());
+      auto *br = tree.Branch(col.name.c_str(), &backFillValue, (col.name + "/" + rootType).c_str(), /*bufsize=*/1024);
       br->SetTitle(col.doc.c_str());
       for (unsigned long i = 0; i < m_fills; i++)
         br->Fill();