[TCP]: cleanup of htcp (resend) (9121c777) · Commits · e / devices / android_kernel_oneplus_sm7250

net/ipv4/tcp_htcp.c

+37 −28

Original line number	Original line	Diff line number	Diff line
	@@ -14,18 +14,19 @@
	#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */		#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */
	#define BETA_MAX 102 /* 0.8 with shift << 7 */		#define BETA_MAX 102 /* 0.8 with shift << 7 */

	static int use_rtt_scaling = 1;		static int use_rtt_scaling __read_mostly = 1;
	module_param(use_rtt_scaling, int, 0644);		module_param(use_rtt_scaling, int, 0644);
	MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling");		MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling");

	static int use_bandwidth_switch = 1;		static int use_bandwidth_switch __read_mostly = 1;
	module_param(use_bandwidth_switch, int, 0644);		module_param(use_bandwidth_switch, int, 0644);
	MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher");		MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher");

	struct htcp {		struct htcp {
	u32 alpha; /* Fixed point arith, << 7 */		u32 alpha; /* Fixed point arith, << 7 */
	u8 beta; /* Fixed point arith, << 7 */		u8 beta; /* Fixed point arith, << 7 */
	u8 modeswitch; /* Delay modeswitch until we had at least one congestion event */		u8 modeswitch; /* Delay modeswitch
			until we had at least one congestion event */
	u16 pkts_acked;		u16 pkts_acked;
	u32 packetcount;		u32 packetcount;
	u32 minRTT;		u32 minRTT;
	@@ -44,12 +45,12 @@ struct htcp {
	u32 lasttime;		u32 lasttime;
	};		};

	static inline u32 htcp_cong_time(struct htcp *ca)		static inline u32 htcp_cong_time(const struct htcp *ca)
	{		{
	return jiffies - ca->last_cong;		return jiffies - ca->last_cong;
	}		}

	static inline u32 htcp_ccount(struct htcp *ca)		static inline u32 htcp_ccount(const struct htcp *ca)
	{		{
	return htcp_cong_time(ca) / ca->minRTT;		return htcp_cong_time(ca) / ca->minRTT;
	}		}
	@@ -67,9 +68,11 @@ static u32 htcp_cwnd_undo(struct sock *sk)
	{		{
	const struct tcp_sock *tp = tcp_sk(sk);		const struct tcp_sock *tp = tcp_sk(sk);
	struct htcp *ca = inet_csk_ca(sk);		struct htcp *ca = inet_csk_ca(sk);

	ca->last_cong = ca->undo_last_cong;		ca->last_cong = ca->undo_last_cong;
	ca->maxRTT = ca->undo_maxRTT;		ca->maxRTT = ca->undo_maxRTT;
	ca->old_maxB = ca->undo_old_maxB;		ca->old_maxB = ca->undo_old_maxB;

	return max(tp->snd_cwnd, (tp->snd_ssthresh << 7) / ca->beta);		return max(tp->snd_cwnd, (tp->snd_ssthresh << 7) / ca->beta);
	}		}

	@@ -85,10 +88,12 @@ static inline void measure_rtt(struct sock *sk)
	ca->minRTT = srtt;		ca->minRTT = srtt;

	/* max RTT */		/* max RTT */
	if (icsk->icsk_ca_state == TCP_CA_Open && tp->snd_ssthresh < 0xFFFF && htcp_ccount(ca) > 3) {		if (icsk->icsk_ca_state == TCP_CA_Open
			&& tp->snd_ssthresh < 0xFFFF && htcp_ccount(ca) > 3) {
	if (ca->maxRTT < ca->minRTT)		if (ca->maxRTT < ca->minRTT)
	ca->maxRTT = ca->minRTT;		ca->maxRTT = ca->minRTT;
	if (ca->maxRTT < srtt && srtt <= ca->maxRTT+msecs_to_jiffies(20))		if (ca->maxRTT < srtt
			&& srtt <= ca->maxRTT + msecs_to_jiffies(20))
	ca->maxRTT = srtt;		ca->maxRTT = srtt;
	}		}
	}		}
	@@ -120,6 +125,7 @@ static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked)
	&& now - ca->lasttime >= ca->minRTT		&& now - ca->lasttime >= ca->minRTT
	&& ca->minRTT > 0) {		&& ca->minRTT > 0) {
	__u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime);		__u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime);

	if (htcp_ccount(ca) <= 3) {		if (htcp_ccount(ca) <= 3) {
	/* just after backoff */		/* just after backoff */
	ca->minB = ca->maxB = ca->Bi = cur_Bi;		ca->minB = ca->maxB = ca->Bi = cur_Bi;
	@@ -174,7 +180,9 @@ static inline void htcp_alpha_update(struct htcp *ca)

	if (use_rtt_scaling && minRTT) {		if (use_rtt_scaling && minRTT) {
	u32 scale = (HZ << 3) / (10 * minRTT);		u32 scale = (HZ << 3) / (10 * minRTT);
	scale = min(max(scale, 1U<<2), 10U<<3); /* clamping ratio to interval [0.5,10]<<3 */
			/* clamping ratio to interval [0.5,10]<<3 */
			scale = min(max(scale, 1U << 2), 10U << 3);
	factor = (factor << 3) / scale;		factor = (factor << 3) / scale;
	if (!factor)		if (!factor)
	factor = 1;		factor = 1;
	@@ -185,7 +193,8 @@ static inline void htcp_alpha_update(struct htcp *ca)
	ca->alpha = ALPHA_BASE;		ca->alpha = ALPHA_BASE;
	}		}

	/* After we have the rtt data to calculate beta, we'd still prefer to wait one		/*
			* After we have the rtt data to calculate beta, we'd still prefer to wait one
	* rtt before we adjust our beta to ensure we are working from a consistent		* rtt before we adjust our beta to ensure we are working from a consistent
	* data.		* data.
	*		*
	@@ -202,7 +211,7 @@ static void htcp_param_update(struct sock *sk)
	htcp_beta_update(ca, minRTT, maxRTT);		htcp_beta_update(ca, minRTT, maxRTT);
	htcp_alpha_update(ca);		htcp_alpha_update(ca);

	/* add slowly fading memory for maxRTT to accommodate routing changes etc */		/* add slowly fading memory for maxRTT to accommodate routing changes */
	if (minRTT > 0 && maxRTT > minRTT)		if (minRTT > 0 && maxRTT > minRTT)
	ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;		ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
	}		}
	@@ -211,6 +220,7 @@ static u32 htcp_recalc_ssthresh(struct sock *sk)
	{		{
	const struct tcp_sock *tp = tcp_sk(sk);		const struct tcp_sock *tp = tcp_sk(sk);
	const struct htcp *ca = inet_csk_ca(sk);		const struct htcp *ca = inet_csk_ca(sk);

	htcp_param_update(sk);		htcp_param_update(sk);
	return max((tp->snd_cwnd * ca->beta) >> 7, 2U);		return max((tp->snd_cwnd * ca->beta) >> 7, 2U);
	}		}
	@@ -227,7 +237,6 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
	if (tp->snd_cwnd <= tp->snd_ssthresh)		if (tp->snd_cwnd <= tp->snd_ssthresh)
	tcp_slow_start(tp);		tcp_slow_start(tp);
	else {		else {

	measure_rtt(sk);		measure_rtt(sk);

	/* In dangerous area, increase slowly.		/* In dangerous area, increase slowly.