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>
u64 rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* Determined RTT cache */
u8 rtt_cursor; /* next entry at which to insert */
u8 rtt_usage; /* amount of cache actually used */
u64 rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* Determined RTT cache */
u8 rtt_cursor; /* next entry at which to insert */
u8 rtt_usage; /* amount of cache actually used */
+
+ u8 cong_cwnd; /* Congestion window size */
rxrpc_see_call(call);
call->conn = conn;
call->peer = rxrpc_get_peer(conn->params.peer);
rxrpc_see_call(call);
call->conn = conn;
call->peer = rxrpc_get_peer(conn->params.peer);
+ call->cong_cwnd = call->peer->cong_cwnd;
call->tx_winsize = 16;
call->rx_expect_next = 1;
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_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
return call;
call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
return call;
if (!cp->peer)
goto error;
if (!cp->peer)
goto error;
+ call->cong_cwnd = cp->peer->cong_cwnd;
+ if (call->cong_cwnd >= call->cong_ssthresh)
+ call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+ else
+ call->cong_mode = RXRPC_CALL_SLOW_START;
+
/* If the connection is not meant to be exclusive, search the available
* connections to see if the connection we want to use already exists.
*/
/* If the connection is not meant to be exclusive, search the available
* connections to see if the connection we want to use already exists.
*/
{
struct rxrpc_connection *conn = call->conn;
{
struct rxrpc_connection *conn = call->conn;
+ call->peer->cong_cwnd = call->cong_cwnd;
+
spin_lock_bh(&conn->params.peer->lock);
hlist_del_init(&call->error_link);
spin_unlock_bh(&conn->params.peer->lock);
spin_lock_bh(&conn->params.peer->lock);
hlist_del_init(&call->error_link);
spin_unlock_bh(&conn->params.peer->lock);
seqlock_init(&peer->service_conn_lock);
spin_lock_init(&peer->lock);
peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
seqlock_init(&peer->service_conn_lock);
spin_lock_init(&peer->lock);
peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
+
+ if (RXRPC_TX_SMSS > 2190)
+ peer->cong_cwnd = 2;
+ else if (RXRPC_TX_SMSS > 1095)
+ peer->cong_cwnd = 3;
+ else
+ peer->cong_cwnd = 4;