file: /proc/sys/net/ipv4/cipso_cache_enable
variable: net.ipv4.cipso_cache_enable
Official reference

If set, enable additions to and lookups from the CIPSO label mapping cache. If unset, additions are ignored and lookups always result in a miss. However, regardless of the setting the cache is still invalidated when required when means you can safely toggle this on and off and the cache will always be “safe”. Default: 1