private static File getLogDir(File logFile) {
    File logDir = null;
    if (logFile != null) {
      logDir = logFile.getParentFile();
    }

    if (logDir == null) {
      // assume current directory
      logDir = new File(".");
    }
    return logDir;
  }
Validates the critical percent.

@param val the value to check
geode-core/src/main/java/org/apache/geode/internal/cache/DiskStoreMonitor.java