Reproduce Memory higher memory usage in 6.20 and 6.22 when reading trees

repro3.C

void memory()
{
   ProcInfo_t info;
   gSystem->GetProcInfo(&info);
   printf(" res  memory = %g Mbytes\n",info.fMemResident/1024.);
}


int repro3() {
  auto infiles = {
      "/eos/cms/store/user/srimanob/hlttdr/CMSSW_11_1_0/DQM/step1_WithValidation_inDQM_18.root",
      "/eos/cms/store/user/srimanob/hlttdr/CMSSW_11_1_0/DQM/step1_WithValidation_inDQM_19.root"};

  for (auto tname : {"TH1Fs","TH2Fs"}) {
    for (auto infile : infiles) {
      auto tf = TFile::Open(infile);
      std::cout << "Reading " << tname << " from " << tf->GetName() << "\n";
      auto m_tree = tf->Get<TTree>(tname);
      int max = m_tree->GetEntries();
      for (int i = 0; i < max; i++) { m_tree->GetEntry(i);}
      memory();
      }
    }

  return 0;
}