rxrpc: Cache the congestion window setting

Cache the congestion window setting that was determined during a call's
transmission phase when it finishes so that it can be used by the next call
to the same peer, thereby shortcutting the slow-start algorithm.

The value is stored in the rxrpc_peer struct and is accessed without
locking.  Each call takes the value that happens to be there when it starts
and just overwrites the value when it finishes.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 6 deletions

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 423030fd93be..d7809a0620b4 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -136,12 +136,7 @@ struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
         call->tx_winsize = 16;
         call->rx_expect_next = 1;
 
-        if (RXRPC_TX_SMSS > 2190)
-                call->cong_cwnd = 2;
-        else if (RXRPC_TX_SMSS > 1095)
-                call->cong_cwnd = 3;
-        else
-                call->cong_cwnd = 4;
+        call->cong_cwnd = 2;
         call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
         return call;