Hi David

Please find patch to convert TCP/DCCP listening hash tables
to RCU.

A followup patch will cleanup all sk_node fields and macros
that are not used anymore.

Thanks

[PATCH] net: Convert TCP/DCCP listening hash tables to use RCU

This is the last step to be able to perform full RCU lookups
in __inet_lookup() : After established/timewait tables, we
add RCU lookups to listening hash table.

The only trick here is that a socket of a given type (TCP ipv4,
TCP ipv6, ...) can now flight between two different tables
(established and listening) during a RCU grace period, so we
must use different 'nulls' end-of-chain values for two tables.

We define a large value :

#define LISTENING_NULLS_BASE (1U << 29)

So that slots in listening table are guaranteed to have different
end-of-chain values than slots in established table. A reader can
still detect it finished its lookup in the right chain.

Signed-off-by: Eric Dumazet <redacted>
---
 include/net/inet_hashtables.h |    9 +
 net/ipv4/inet_diag.c          |    4
 net/ipv4/inet_hashtables.c    |  148 ++++++++++++++++----------------
 net/ipv4/tcp_ipv4.c           |    8 -
 net/ipv6/inet6_hashtables.c   |   94 ++++++++++++--------
 5 files changed, 147 insertions(+), 116 deletions(-)