[DCCP] ccid3: Track RX/TX packet size `s' using moving-average (78ad713d) · Commits · e / devices / android_kernel_teracube_2e

net/dccp/ccids/ccid3.c

+41 −19

Original line number	Diff line number	Diff line
		@@ -159,6 +159,25 @@ static void ccid3_hc_tx_update_x(struct sock *sk)
		ccid3_update_send_time(hctx);
		}

		/*
		* Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
		* @len: DCCP packet payload size in bytes
		*/
		static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
		{
		if (unlikely(len == 0))
		ccid3_pr_debug("Packet payload length is 0 - not updating\n");
		else
		hctx->ccid3hctx_s = hctx->ccid3hctx_s == 0 ? len :
		(9 * hctx->ccid3hctx_s + len) / 10;
		/*
		* Note: We could do a potential optimisation here - when `s' changes,
		* recalculate sending rate and consequently t_ipi, t_delta, and
		* t_now. This is however non-standard, and the benefits are not
		* clear, so it is currently left out.
		*/
		}

		static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
		{
		struct sock sk = (struct sock )data;
		@@ -299,6 +318,10 @@ static int ccid3_hc_tx_send_packet(struct sock *sk,
		hctx->ccid3hctx_t_last_win_count = now;
		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);

		/* Set initial sending rate to 1 packet per second */
		ccid3_hc_tx_update_s(hctx, len);
		hctx->ccid3hctx_x = hctx->ccid3hctx_s;

		/* First timeout, according to [RFC 3448, 4.2], is 1 second */
		hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
		/* Initial delta: minimum of 0.5 sec and t_gran/2 */
		@@ -350,6 +373,8 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
		unsigned long quarter_rtt;
		struct dccp_tx_hist_entry *packet;

		ccid3_hc_tx_update_s(hctx, len);

		packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
		if (unlikely(packet == NULL)) {
		DCCP_WARN("packet doesn't exist in history!\n");
		@@ -594,17 +619,9 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,

		static int ccid3_hc_tx_init(struct ccid ccid, struct sock sk)
		{
		struct dccp_sock *dp = dccp_sk(sk);
		struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);

		if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
		dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
		hctx->ccid3hctx_s = dp->dccps_packet_size;
		else
		hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;

		/* Set transmission rate to 1 packet per second */
		hctx->ccid3hctx_x = hctx->ccid3hctx_s;
		hctx->ccid3hctx_s = 0;
		hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
		INIT_LIST_HEAD(&hctx->ccid3hctx_hist);

		@@ -658,6 +675,15 @@ static void ccid3_hc_rx_set_state(struct sock *sk,
		hcrx->ccid3hcrx_state = state;
		}

		static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
		{
		if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
		ccid3_pr_debug("Packet payload length is 0 - not updating\n");
		else
		hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
		(9 * hcrx->ccid3hcrx_s + len) / 10;
		}

		static void ccid3_hc_rx_send_feedback(struct sock *sk)
		{
		struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
		@@ -934,7 +960,7 @@ static void ccid3_hc_rx_packet_recv(struct sock sk, struct sk_buff skb)
		struct dccp_rx_hist_entry *packet;
		struct timeval now;
		u32 p_prev, rtt_prev, r_sample, t_elapsed;
		int loss;
		int loss, payload_size;

		BUG_ON(hcrx == NULL);

		@@ -989,6 +1015,9 @@ static void ccid3_hc_rx_packet_recv(struct sock sk, struct sk_buff skb)
		if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
		return;

		payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
		ccid3_hc_rx_update_s(hcrx, payload_size);

		switch (hcrx->ccid3hcrx_state) {
		case TFRC_RSTATE_NO_DATA:
		ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
		@@ -999,8 +1028,7 @@ static void ccid3_hc_rx_packet_recv(struct sock sk, struct sk_buff skb)
		ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
		return;
		case TFRC_RSTATE_DATA:
		hcrx->ccid3hcrx_bytes_recv += skb->len -
		dccp_hdr(skb)->dccph_doff * 4;
		hcrx->ccid3hcrx_bytes_recv += payload_size;
		if (loss)
		break;

		@@ -1040,22 +1068,16 @@ static void ccid3_hc_rx_packet_recv(struct sock sk, struct sk_buff skb)

		static int ccid3_hc_rx_init(struct ccid ccid, struct sock sk)
		{
		struct dccp_sock *dp = dccp_sk(sk);
		struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);

		ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);

		if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
		dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
		hcrx->ccid3hcrx_s = dp->dccps_packet_size;
		else
		hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;

		hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
		INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
		INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
		dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
		hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
		hcrx->ccid3hcrx_s = 0;
		hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
		return 0;
		}