Socket caching means Onload can further reduce the overhead of setting up new TCP connections by reusing existing sockets instead of creating from new.
A cached socket retains a file descriptor and socket buffer when it is returned to the cache of the Onload stack from which it originated.
Socket caching is enabled when EF_SOCKET_CACHE_MAX is set to a value greater than zero. Onload will apply passive or active caching as appropriate for the type of sockets created by the user application.
EF_SOCKET_CACHE_MAX applies to both active and passive sockets, so if set to 100 the cache limit is 100 of each socket type.