dccp ccid-2: Stop polling

This updates CCID-2 to use the CCID dequeuing mechanism, converting from
previous continuous-polling to a now event-driven mechanism.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index d850e29..6576eae 100644 (file)
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -78,12 +78,9 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hc)
 
 static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 {
-       struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-
-       if (hc->tx_pipe < hc->tx_cwnd)
-               return 0;
-
-       return 1; /* XXX CCID should dequeue when ready instead of polling */
+       if (ccid2_cwnd_network_limited(ccid2_hc_tx_sk(sk)))
+               return CCID_PACKET_WILL_DEQUEUE_LATER;
+       return CCID_PACKET_SEND_AT_ONCE;
 }
 
 static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val)
@@ -115,6 +112,7 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
 {
        struct sock *sk = (struct sock *)data;
        struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+       const bool sender_was_blocked = ccid2_cwnd_network_limited(hc);
 
        bh_lock_sock(sk);
        if (sock_owned_by_user(sk)) {
@@ -129,8 +127,6 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
        if (hc->tx_rto > DCCP_RTO_MAX)
                hc->tx_rto = DCCP_RTO_MAX;
 
-       sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
-
        /* adjust pipe, cwnd etc */
        hc->tx_ssthresh = hc->tx_cwnd / 2;
        if (hc->tx_ssthresh < 2)
@@ -146,6 +142,12 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
        hc->tx_rpseq    = 0;
        hc->tx_rpdupack = -1;
        ccid2_change_l_ack_ratio(sk, 1);
+
+       /* if we were blocked before, we may now send cwnd=1 packet */
+       if (sender_was_blocked)
+               tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet);
+       /* restart backed-off timer */
+       sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
 out:
        bh_unlock_sock(sk);
        sock_put(sk);
@@ -434,6 +436,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 {
        struct dccp_sock *dp = dccp_sk(sk);
        struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+       const bool sender_was_blocked = ccid2_cwnd_network_limited(hc);
        u64 ackno, seqno;
        struct ccid2_seq *seqp;
        unsigned char *vector;
@@ -631,6 +634,10 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
                sk_stop_timer(sk, &hc->tx_rtotimer);
        else
                sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
+
+       /* check if incoming Acks allow pending packets to be sent */
+       if (sender_was_blocked && !ccid2_cwnd_network_limited(hc))
+               tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet);
 }
 
 static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)

diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index 9731c2d..25cb6b2 100644 (file)
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -81,6 +81,11 @@ struct ccid2_hc_tx_sock {
        u64                     tx_high_ack;
 };
 
+static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc)
+{
+       return hc->tx_pipe >= hc->tx_cwnd;
+}
+
 struct ccid2_hc_rx_sock {
        int     rx_data;
 };