sbool linux_rssFixedForZGC_verbose;

static long linux_rssFixedForZGC() {
  ret linux_rssFixedForZGC(processID_int());
}

static long linux_rssFixedForZGC(int pid) {
  S text = loadTextFile("/proc/" + pid + "/smaps");

  S range = null;
  new TreeMap<S, Long> rssByRange;
  for (S s : lines(text)) {
    S addr = regexpFirstGroupIC("^([0-9a-f]{1,16})-", s);
    if (addr != null) {
      addr = lpad(addr, 16, '0');
      //print("Have address: " + addr);
      S cleanedAddr = longToHex(parseUnsignedHexLong(addr) & ~((1L << 42)-1));
      //range = takeFirst(/*7*/6, addr);
      range = takeFirst(6, cleanedAddr);
      continue;
    } // else print("Not range: " + s);
    PairS p = parseColonProperty(s);
    if (eqic(pairA(p), "rss")) {
      long size = parseFirstLong(p.b);
      if (size != 0)
        rssByRange.put(range, getOrCreate_long(rssByRange, range) + size);
    }
  }
  if (linux_rssFixedForZGC_verbose)
    for (unpair S _range, long size : mapToPairs(rssByRange)) {
      print("Address range " + rpad(_range, 16, 'x') + ": " + toK(size) + " MB");
    }
  L<Long> offendingRanges = ll(
    toLong(rssByRange.get("000004")),
    toLong(rssByRange.get("000008")),
    toLong(rssByRange.get("000010")));
  
  long total = longSum(values(rssByRange));
  long offending = longMin(offendingRanges);
  long guess = total-offending*2 /*3*/; // seems 2 is the right one
  
  /* Bad fix (?) for this situation:
    Address range 000000xxxxxxxxxx: 1 MB
    Address range 000004xxxxxxxxxx: 2461 MB
    Address range 000008xxxxxxxxxx: 2476 MB
    Address range 000010xxxxxxxxxx: 2662 MB
    Address range 00007cxxxxxxxxxx: 648 MB
  */
  /*long high = toLong(rssByRange.get("00007c"));
  if (high < offending*2)
    guess += offending;*/
  
  ret guess*1024;
}

Began life as a copy of #1025541