diff options
| -rw-r--r-- | net/dccp/ccids/ccid2.c | 23 | ||||
| -rw-r--r-- | net/dccp/ccids/ccid2.h | 4 |
2 files changed, 21 insertions, 6 deletions
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c index 9c5b6c73f7c..a901202ada6 100644 --- a/net/dccp/ccids/ccid2.c +++ b/net/dccp/ccids/ccid2.c @@ -224,8 +224,6 @@ static void ccid2_hc_tx_rto_expire(unsigned long data) hctx->ccid2hctx_sent = 0; /* clear ack ratio state. */ - hctx->ccid2hctx_arsent = 0; - hctx->ccid2hctx_ackloss = 0; hctx->ccid2hctx_rpseq = 0; hctx->ccid2hctx_rpdupack = -1; ccid2_change_l_ack_ratio(sk, 1); @@ -289,6 +287,26 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) hctx->ccid2hctx_sent++; + /* + * FIXME: The code below is broken and the variables have been removed + * from the socket struct. The `ackloss' variable was always set to 0, + * and with arsent there are several problems: + * (i) it doesn't just count the number of Acks, but all sent packets; + * (ii) it is expressed in # of packets, not # of windows, so the + * comparison below uses the wrong formula: Appendix A of RFC 4341 + * comes up with the number K = cwnd / (R^2 - R) of consecutive windows + * of data with no lost or marked Ack packets. If arsent were the # of + * consecutive Acks received without loss, then Ack Ratio needs to be + * decreased by 1 when + * arsent >= K * cwnd / R = cwnd^2 / (R^3 - R^2) + * where cwnd / R is the number of Acks received per window of data + * (cf. RFC 4341, App. A). The problems are that + * - arsent counts other packets as well; + * - the comparison uses a formula different from RFC 4341; + * - computing a cubic/quadratic equation each time is too complicated. + * Hence a different algorithm is needed. + */ +#if 0 /* Ack Ratio. Need to maintain a concept of how many windows we sent */ hctx->ccid2hctx_arsent++; /* We had an ack loss in this window... */ @@ -316,6 +334,7 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ } } +#endif /* setup RTO timer */ if (!timer_pending(&hctx->ccid2hctx_rtotimer)) diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h index d9daa534c9b..ed95f8f0cc4 100644 --- a/net/dccp/ccids/ccid2.h +++ b/net/dccp/ccids/ccid2.h @@ -44,8 +44,6 @@ struct ccid2_seq { * @ccid2hctx_acks - ACKS recv in AI phase * @ccid2hctx_sent - packets sent in this window * @ccid2hctx_lastrtt -time RTT was last measured - * @ccid2hctx_arsent - packets sent [ack ratio] - * @ccid2hctx_ackloss - ack was lost in this win * @ccid2hctx_rpseq - last consecutive seqno * @ccid2hctx_rpdupack - dupacks since rpseq */ @@ -66,8 +64,6 @@ struct ccid2_hc_tx_sock { int ccid2hctx_sent; unsigned long ccid2hctx_lastrtt; struct timer_list ccid2hctx_rtotimer; - unsigned long ccid2hctx_arsent; - int ccid2hctx_ackloss; u64 ccid2hctx_rpseq; int ccid2hctx_rpdupack; int ccid2hctx_sendwait; |