message: Tune jemalloc config
  Summary: Tune jemalloc config for better perf.
diff: @@ -109,6 +109,10 @@ def add_extra_environment_args(env):
  "MALLOC_CONF"
  ] = "prof:true,prof_prefix:jeprof.out,prof_gdump:true,prof_active:false"
  + # If we haven't set MALLOC_CONF, tune MALLOC_CONF for better perf
  + if "MALLOC_CONF" not in env:
  + env["MALLOC_CONF"] = "background_thread:true,metadata_thp:always,thp:always"
  +
  def get_stop_pass_idx(passes_list, pass_name_and_num):
  # Get the stop position
  