sctp: Update SWS avaoidance receiver side algorithm

We currently send window update SACKs every time we free up 1 PMTU
worth of data.  That a lot more SACKs then necessary.  Instead, we'll
now send back the actuall window every time we send a sack, and do
window-update SACKs when a fraction of the receive buffer has been
opened.  The fraction is controlled with a sysctl.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 08ef203d36ac..a3c8988758b1 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -1258,6 +1258,9 @@ SCTP_STATIC __init int sctp_init(void)
         /* Set SCOPE policy to enabled */
         sctp_scope_policy = SCTP_SCOPE_POLICY_ENABLE;
 
+        /* Set the default rwnd update threshold */
+        sctp_rwnd_upd_shift             = SCTP_DEFAULT_RWND_SHIFT;
+
         sctp_sysctl_register();
 
         INIT_LIST_HEAD(&sctp_address_families);