Error message

• Warning: include_once(): Unable to allocate memory for pool. in drupal_settings_initialize() (line 747 of /var/www/html/includes/bootstrap.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_configuration() (line 2637 of /var/www/html/includes/bootstrap.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_page_cache() (line 2649 of /var/www/html/includes/bootstrap.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_database() (line 2739 of /var/www/html/includes/bootstrap.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_variables() (line 2759 of /var/www/html/includes/bootstrap.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_variables() (line 2765 of /var/www/html/includes/bootstrap.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_full() (line 5266 of /var/www/html/includes/common.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_full() (line 5267 of /var/www/html/includes/common.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_full() (line 5268 of /var/www/html/includes/common.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_full() (line 5269 of /var/www/html/includes/common.inc).
• Warning: require_once(): Unable to allocate memory for pool. in _drupal_bootstrap_full() (line 5270 of /var/www/html/includes/common.inc).
• Warning: include_once(): Unable to allocate memory for pool. in drupal_load() (line 1374 of /var/www/html/includes/bootstrap.inc).