XFRM Policy lookup in flowcache

Hi All,

I have a question regarding speeding up xfrm policy lookup in flow cache.

We are working on a product where  3 policies (in,fwd and out) are
setup per tunnel.

Tunnels comes up and down all the time, so the policy data base will
be keep changing.

Looks like there is an impact in performance since every time policy
database is changed, policies in flow cache gets invalidated. This
eventually results in almost all lookups going to policy database.

Is there any mechanism to get around this to get faster policy lookup?

thanks

--naji