tree 9dd99b27be4dc469954a2d67515593c9f71cbcd0
parent ab92bb2f679d66c7e12a6b1c0cdd76fe308f6546
author David S. Miller <davem@davemloft.net> 1341906554 -0700
committer David S. Miller <davem@davemloft.net> 1341985197 -0700

tcp: Maintain dynamic metrics in local cache.

Maintain a local hash table of TCP dynamic metrics blobs.

Computed TCP metrics are no longer maintained in the route metrics.

The table uses RCU and an extremely simple hash so that it has low
latency and low overhead.  A simple hash is legitimate because we only
make metrics blobs for fully established connections.

Some tweaking of the default hash table sizes, metric timeouts, and
the hash chain length limit certainly could use some tweaking.  But
the basic design seems sound.

With help from Eric Dumazet and Joe Perches.

Signed-off-by: David S. Miller <davem@davemloft.net>