Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 17a6e9f1 authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller
Browse files

tcp_cubic: fix clock dependency 



The hystart code was written with assumption that HZ=1000.
Replace the use of jiffies with bictcp_clock as a millisecond
real time clock.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Reported-by: default avatarLucas Nussbaum <lucas.nussbaum@loria.fr>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent aac46324

net/ipv4/tcp_cubic.c

+19 −12
Original line number Original line Diff line number Diff line
@@ -88,7 +88,7 @@ struct bictcp { 
	u32	last_time;	/* time when updated last_cwnd */

	u32	last_time;	/* time when updated last_cwnd */

	u32	bic_origin_point;/* origin point of bic function */

	u32	bic_origin_point;/* origin point of bic function */

	u32	bic_K;		/* time to origin point from the beginning of the current epoch */

	u32	bic_K;		/* time to origin point from the beginning of the current epoch */

	u32	delay_min;	/* min delay */

	u32	delay_min;	/* min delay (msec << 3) */

	u32	epoch_start;	/* beginning of an epoch */

	u32	epoch_start;	/* beginning of an epoch */

	u32	ack_cnt;	/* number of acks */

	u32	ack_cnt;	/* number of acks */

	u32	tcp_cwnd;	/* estimated tcp cwnd */

	u32	tcp_cwnd;	/* estimated tcp cwnd */
@@ -98,7 +98,7 @@ struct bictcp { 
	u8	found;		/* the exit point is found? */

	u8	found;		/* the exit point is found? */

	u32	round_start;	/* beginning of each round */

	u32	round_start;	/* beginning of each round */

	u32	end_seq;	/* end_seq of the round */

	u32	end_seq;	/* end_seq of the round */

	u32	last_jiffies;	/* last time when the ACK spacing is close */

	u32	last_ack;	/* last time when the ACK spacing is close */

	u32	curr_rtt;	/* the minimum rtt of current round */

	u32	curr_rtt;	/* the minimum rtt of current round */

};

};
@@ -119,12 +119,21 @@ static inline void bictcp_reset(struct bictcp *ca) 
	ca->found = 0;

	ca->found = 0;

}

}





static inline u32 bictcp_clock(void)

{

#if HZ < 1000

	return ktime_to_ms(ktime_get_real());

#else

	return jiffies_to_msecs(jiffies);

#endif

}



static inline void bictcp_hystart_reset(struct sock *sk)

static inline void bictcp_hystart_reset(struct sock *sk)

{

{

	struct tcp_sock *tp = tcp_sk(sk);

	struct tcp_sock *tp = tcp_sk(sk);

	struct bictcp *ca = inet_csk_ca(sk);

	struct bictcp *ca = inet_csk_ca(sk);





	ca->round_start = ca->last_jiffies = jiffies;

	ca->round_start = ca->last_ack = bictcp_clock();

	ca->end_seq = tp->snd_nxt;

	ca->end_seq = tp->snd_nxt;

	ca->curr_rtt = 0;

	ca->curr_rtt = 0;

	ca->sample_cnt = 0;

	ca->sample_cnt = 0;
@@ -239,8 +248,8 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd) 
	 */

	 */





	/* change the unit from HZ to bictcp_HZ */

	/* change the unit from HZ to bictcp_HZ */

	t = ((tcp_time_stamp + (ca->delay_min>>3) - ca->epoch_start)

	t = ((tcp_time_stamp + msecs_to_jiffies(ca->delay_min>>3)

	     << BICTCP_HZ) / HZ;

	      - ca->epoch_start) << BICTCP_HZ) / HZ;





	if (t < ca->bic_K)		/* t - K */

	if (t < ca->bic_K)		/* t - K */

		offs = ca->bic_K - t;

		offs = ca->bic_K - t;
@@ -342,14 +351,12 @@ static void hystart_update(struct sock *sk, u32 delay) 
	struct bictcp *ca = inet_csk_ca(sk);

	struct bictcp *ca = inet_csk_ca(sk);





	if (!(ca->found & hystart_detect)) {

	if (!(ca->found & hystart_detect)) {

		u32 curr_jiffies = jiffies;

		u32 now = bictcp_clock();





		/* first detection parameter - ack-train detection */

		/* first detection parameter - ack-train detection */

		if ((s32)(curr_jiffies - ca->last_jiffies) <=

		if ((s32)(now - ca->last_ack) <= hystart_ack_delta) {

		    msecs_to_jiffies(hystart_ack_delta)) {

			ca->last_ack = now;

			ca->last_jiffies = curr_jiffies;

			if ((s32)(now - ca->round_start) > ca->delay_min >> 4)

			if ((s32) (curr_jiffies - ca->round_start) >

			    ca->delay_min >> 4)

				ca->found |= HYSTART_ACK_TRAIN;

				ca->found |= HYSTART_ACK_TRAIN;

		}

		}
@@ -396,7 +403,7 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us) 
	if ((s32)(tcp_time_stamp - ca->epoch_start) < HZ)

	if ((s32)(tcp_time_stamp - ca->epoch_start) < HZ)

		return;

		return;





	delay = usecs_to_jiffies(rtt_us) << 3;

	delay = (rtt_us << 3) / USEC_PER_MSEC;

	if (delay == 0)

	if (delay == 0)

		delay = 1;

		delay = 1;