Subject: [PATCH net-next 0/3] RDS: RDS-TCP perf enhancements

From: Sowmini Varadhan <[email-masked]>
Date: Wed, 30 Sep 2015 09:45:51 -0400

A 3-part patchset that (a) improves current RDS-TCP perf
by 2X-3X and (b) refactors earlier robustness code for
better observability/scaling.

Patch 1 is an enhancment of earlier robustness fixes 
that had used separate sockets for client and server endpoints to
resolve race conditions. It is possible to have an equivalent
solution that does not use 2 sockets. The benefit of a
single socket solution is that it results in more predictable
and observable behavior for the underlying TCP pipe of an 
RDS connection

Patches 2 and 3 are simple, straightforward perf bug fixes
that align the RDS TCP socket with other parts of the kernel stack.

Sowmini Varadhan (3):
  Use a single TCP socket for both send and receive.
  Do not bloat sndbuf/rcvbuf in rds_tcp_tune
  Set up MSG_MORE and MSG_SENDPAGE_NOTLAST as appropriate in
    rds_tcp_xmit

 net/rds/connection.c |   22 ++++++----------------
 net/rds/rds.h        |    4 +++-
 net/rds/tcp.c        |   16 ++++------------
 net/rds/tcp_listen.c |   19 +++++++------------
 net/rds/tcp_send.c   |    8 +++++++-
 5 files changed, 27 insertions(+), 42 deletions(-)