[DCCP] CCID2: Initialize ssthresh to infinity

Initialize the slow-start threshold to infinity.  This way, upon connection
initiation, slow-start will be exited only upon a packet loss.  This patch will
allow connections to quickly gain speed.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 3 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 54a6b7ef3b7..699a5667465 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -678,9 +678,12 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
         int seqcount = ccid2_seq_len;
         int i;
 
-        /* XXX init variables with proper values */
         hctx->ccid2hctx_cwnd      = 1;
-        hctx->ccid2hctx_ssthresh  = 10;
+        /* Initialize ssthresh to infinity.  This means that we will exit the
+         * initial slow-start after the first packet loss.  This is what we
+         * want.
+         */
+        hctx->ccid2hctx_ssthresh  = ~0;
         hctx->ccid2hctx_numdupack = 3;
 
         /* XXX init ~ to window size... */
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index 451a87464fa..b4cc6c0bf02 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -50,7 +50,7 @@ struct ccid2_hc_tx_sock {
         int                     ccid2hctx_cwnd;
         int                     ccid2hctx_ssacks;
         int                     ccid2hctx_acks;
-        int                     ccid2hctx_ssthresh;
+        unsigned int            ccid2hctx_ssthresh;
         int                     ccid2hctx_pipe;
         int                     ccid2hctx_numdupack;
         struct ccid2_seq        *ccid2hctx_seqbuf;