Differential D33035 Diff 102444 sys/netinet/cc/cc_cubic.c

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sys/netinet/cc/cc_cubic.c

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#include <net/route.h>		#include <net/route.h>
#include <net/route/nhop.h>		#include <net/route/nhop.h>

#include <netinet/in_pcb.h>		#include <netinet/in_pcb.h>
#include <netinet/tcp.h>		#include <netinet/tcp.h>
#include <netinet/tcp_seq.h>		#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>		#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>		#include <netinet/tcp_var.h>
		#include <netinet/tcp_log_buf.h>
		#include <netinet/tcp_hpts.h>
#include <netinet/cc/cc.h>		#include <netinet/cc/cc.h>
#include <netinet/cc/cc_cubic.h>		#include <netinet/cc/cc_cubic.h>
#include <netinet/cc/cc_module.h>		#include <netinet/cc/cc_module.h>

static void cubic_ack_received(struct cc_var *ccv, uint16_t type);		static void cubic_ack_received(struct cc_var *ccv, uint16_t type);
static void cubic_cb_destroy(struct cc_var *ccv);		static void cubic_cb_destroy(struct cc_var *ccv);
static int cubic_cb_init(struct cc_var ccv, void ptr);		static int cubic_cb_init(struct cc_var ccv, void ptr);
static void cubic_cong_signal(struct cc_var *ccv, uint32_t type);		static void cubic_cong_signal(struct cc_var *ccv, uint32_t type);
static void cubic_conn_init(struct cc_var *ccv);		static void cubic_conn_init(struct cc_var *ccv);
static int cubic_mod_init(void);		static int cubic_mod_init(void);
static void cubic_post_recovery(struct cc_var *ccv);		static void cubic_post_recovery(struct cc_var *ccv);
static void cubic_record_rtt(struct cc_var *ccv);		static void cubic_record_rtt(struct cc_var *ccv);
static void cubic_ssthresh_update(struct cc_var *ccv, uint32_t maxseg);		static void cubic_ssthresh_update(struct cc_var *ccv, uint32_t maxseg);
static void cubic_after_idle(struct cc_var *ccv);		static void cubic_after_idle(struct cc_var *ccv);
static size_t cubic_data_sz(void);		static size_t cubic_data_sz(void);
		static void cubic_newround(struct cc_var *ccv, uint32_t round_cnt);
		static void cubic_rttsample(struct cc_var *ccv, uint32_t usec_rtt,
		uint32_t rxtcnt, uint32_t fas);

struct cubic {
/* Cubic K in fixed point form with CUBIC_SHIFT worth of precision. */
int64_t K;
/* Sum of RTT samples across an epoch in ticks. */
int64_t sum_rtt_ticks;
/* cwnd at the most recent congestion event. */
unsigned long max_cwnd;
/* cwnd at the previous congestion event. */
unsigned long prev_max_cwnd;
/* A copy of prev_max_cwnd. Used for CC_RTO_ERR */
unsigned long prev_max_cwnd_cp;
/* various flags */
uint32_t flags;
#define CUBICFLAG_CONG_EVENT 0x00000001 /* congestion experienced */
#define CUBICFLAG_IN_SLOWSTART 0x00000002 /* in slow start */
#define CUBICFLAG_IN_APPLIMIT 0x00000004 /* application limited */
#define CUBICFLAG_RTO_EVENT 0x00000008 /* RTO experienced */
/* Minimum observed rtt in ticks. */
int min_rtt_ticks;
/* Mean observed rtt between congestion epochs. */
int mean_rtt_ticks;
/* ACKs since last congestion event. */
int epoch_ack_count;
/* Timestamp (in ticks) of arriving in congestion avoidance from last
* congestion event.
*/
int t_last_cong;
/* Timestamp (in ticks) of a previous congestion event. Used for
* CC_RTO_ERR.
*/
int t_last_cong_prev;
};

struct cc_algo cubic_cc_algo = {		struct cc_algo cubic_cc_algo = {
.name = "cubic",		.name = "cubic",
.ack_received = cubic_ack_received,		.ack_received = cubic_ack_received,
.cb_destroy = cubic_cb_destroy,		.cb_destroy = cubic_cb_destroy,
.cb_init = cubic_cb_init,		.cb_init = cubic_cb_init,
.cong_signal = cubic_cong_signal,		.cong_signal = cubic_cong_signal,
.conn_init = cubic_conn_init,		.conn_init = cubic_conn_init,
.mod_init = cubic_mod_init,		.mod_init = cubic_mod_init,
.post_recovery = cubic_post_recovery,		.post_recovery = cubic_post_recovery,
.after_idle = cubic_after_idle,		.after_idle = cubic_after_idle,
.cc_data_sz = cubic_data_sz		.cc_data_sz = cubic_data_sz,
		.rttsample = cubic_rttsample,
		.newround = cubic_newround
};		};

static void		static void
		cubic_log_hystart_event(struct cc_var ccv, struct cubic cubicd, uint8_t mod, uint32_t flex1)
		{
		/*
		* Types of logs (mod value)
		* 1 - rtt_thresh in flex1, checking to see if RTT is to great.
		* 2 - rtt is too great, rtt_thresh in flex1.
		* 3 - CSS is active incr in flex1
		* 4 - A new round is beginning flex1 is round count
		* 5 - A new RTT measurement flex1 is the new measurement.
		* 6 - We enter CA ssthresh is also in flex1.
		* 7 - Socket option to change hystart executed opt.val in flex1.
		* 8 - Back out of CSS into SS, flex1 is the css_baseline_minrtt
		* 9 - We enter CA, via an ECN mark.
		* 10 - We enter CA, via a loss.
		* 11 - We have slipped out of SS into CA via cwnd growth.
		* 12 - After idle has re-enabled hystart++
		*/
		struct tcpcb *tp;

		if (hystart_bblogs == 0)
		return;
		tp = ccv->ccvc.tcp;
		if (tp->t_logstate != TCP_LOG_STATE_OFF) {
		union tcp_log_stackspecific log;
		struct timeval tv;

		memset(&log, 0, sizeof(log));
		log.u_bbr.flex1 = flex1;
		log.u_bbr.flex2 = cubicd->css_current_round_minrtt;
		log.u_bbr.flex3 = cubicd->css_lastround_minrtt;
		log.u_bbr.flex4 = cubicd->css_rttsample_count;
		log.u_bbr.flex5 = cubicd->css_entered_at_round;
		log.u_bbr.flex6 = cubicd->css_baseline_minrtt;
		/* We only need bottom 16 bits of flags */
		log.u_bbr.flex7 = cubicd->flags & 0x0000ffff;
		log.u_bbr.flex8 = mod;
		log.u_bbr.epoch = cubicd->css_current_round;
		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
		log.u_bbr.lt_epoch = cubicd->css_fas_at_css_entry;
		log.u_bbr.pkts_out = cubicd->css_last_fas;
		log.u_bbr.delivered = cubicd->css_lowrtt_fas;
		log.u_bbr.pkt_epoch = ccv->flags;
		TCP_LOG_EVENTP(tp, NULL,
		&tp->t_inpcb->inp_socket->so_rcv,
		&tp->t_inpcb->inp_socket->so_snd,
		TCP_HYSTART, 0,
		0, &log, false, &tv);
		}
		}

		static void
		cubic_does_slow_start(struct cc_var ccv, struct cubic cubicd)
		{
		/*
		* In slow-start with ABC enabled and no RTO in sight?
		* (Must not use abc_l_var > 1 if slow starting after
		* an RTO. On RTO, snd_nxt = snd_una, so the
		* snd_nxt == snd_max check is sufficient to
		* handle this).
		*
		* XXXLAS: Find a way to signal SS after RTO that
		* doesn't rely on tcpcb vars.
		*/
		u_int cw = CCV(ccv, snd_cwnd);
		u_int incr = CCV(ccv, t_maxseg);
		ccUnsubmitted Not Done Inline Actions Like a mss is used in cubic_cong_signal(), and as ABC is involved, for accurate calculation, suggest to use "u_int mss = tcp_maxseg(ccv->ccvc.tcp);", and use mss instead of t_maxseg below. cc: Like a mss is used in cubic_cong_signal(), and as ABC is involved, for accurate calculation…
		uint16_t abc_val;

		cubicd->flags \|= CUBICFLAG_IN_SLOWSTART;
		if (ccv->flags & CCF_USE_LOCAL_ABC)
		abc_val = ccv->labc;
		else
		abc_val = V_tcp_abc_l_var;
		if ((ccv->flags & CCF_HYSTART_ALLOWED) &&
		(cubicd->flags & CUBICFLAG_HYSTART_ENABLED) &&
		((cubicd->flags & CUBICFLAG_HYSTART_IN_CSS) == 0)) {
		/*
		* Hystart is allowed and still enabled and we are not yet
		* in CSS. Lets check to see if we can make a decision on
		* if we need to go into CSS.
		*/
		if ((cubicd->css_rttsample_count >= hystart_n_rttsamples) &&
		(cubicd->css_current_round_minrtt != 0xffffffff) &&
		(cubicd->css_lastround_minrtt != 0xffffffff)) {
		uint32_t rtt_thresh;

		/* Clamp (minrtt_thresh, lastround/8, maxrtt_thresh) */
		rtt_thresh = (cubicd->css_lastround_minrtt >> 3);
		if (rtt_thresh < hystart_minrtt_thresh)
		rtt_thresh = hystart_minrtt_thresh;
		if (rtt_thresh > hystart_maxrtt_thresh)
		rtt_thresh = hystart_maxrtt_thresh;
		cubic_log_hystart_event(ccv, cubicd, 1, rtt_thresh);

		if (cubicd->css_current_round_minrtt >= (cubicd->css_lastround_minrtt + rtt_thresh)) {
		/* Enter CSS */
		cubicd->flags \|= CUBICFLAG_HYSTART_IN_CSS;
		cubicd->css_fas_at_css_entry = cubicd->css_lowrtt_fas;
		/*
		* The draft (v4) calls for us to set baseline to css_current_round_min
		* but that can cause an oscillation. We probably shoudl be using
		* css_lastround_minrtt, but the authors insist that will cause
		* issues on exiting early. We will leave the draft version for now
		* but I suspect this is incorrect.
		*/
		cubicd->css_baseline_minrtt = cubicd->css_current_round_minrtt;
		cubicd->css_entered_at_round = cubicd->css_current_round;
		cubic_log_hystart_event(ccv, cubicd, 2, rtt_thresh);
		}
		}
		}
		if (CCV(ccv, snd_nxt) == CCV(ccv, snd_max))
		incr = min(ccv->bytes_this_ack,
		ccv->nsegs * abc_val *
		CCV(ccv, t_maxseg));
		else
		incr = min(ccv->bytes_this_ack, CCV(ccv, t_maxseg));

		/* Only if Hystart is enabled will the flag get set */
		if (cubicd->flags & CUBICFLAG_HYSTART_IN_CSS) {
		incr /= hystart_css_growth_div;
		cubic_log_hystart_event(ccv, cubicd, 3, incr);
		}
		/* ABC is on by default, so incr equals 0 frequently. */
		if (incr > 0)
		CCV(ccv, snd_cwnd) = min((cw + incr),
		TCP_MAXWIN << CCV(ccv, snd_scale));
		}

		static void
cubic_ack_received(struct cc_var *ccv, uint16_t type)		cubic_ack_received(struct cc_var *ccv, uint16_t type)
{		{
struct cubic *cubic_data;		struct cubic *cubic_data;
unsigned long w_tf, w_cubic_next;		unsigned long w_tf, w_cubic_next;
int ticks_since_cong;		int ticks_since_cong;

cubic_data = ccv->cc_data;		cubic_data = ccv->cc_data;
cubic_record_rtt(ccv);		cubic_record_rtt(ccv);

/*		/*
* For a regular ACK and we're not in cong/fast recovery and		* For a regular ACK and we're not in cong/fast recovery and
* we're cwnd limited, always recalculate cwnd.		* we're cwnd limited, always recalculate cwnd.
*/		*/
if (type == CC_ACK && !IN_RECOVERY(CCV(ccv, t_flags)) &&		if (type == CC_ACK && !IN_RECOVERY(CCV(ccv, t_flags)) &&
(ccv->flags & CCF_CWND_LIMITED)) {		(ccv->flags & CCF_CWND_LIMITED)) {
/* Use the logic in NewReno ack_received() for slow start. */		/* Use the logic in NewReno ack_received() for slow start. */
if (CCV(ccv, snd_cwnd) <= CCV(ccv, snd_ssthresh) \|\|		if (CCV(ccv, snd_cwnd) <= CCV(ccv, snd_ssthresh) \|\|
cubic_data->min_rtt_ticks == TCPTV_SRTTBASE) {		cubic_data->min_rtt_ticks == TCPTV_SRTTBASE) {
cubic_data->flags \|= CUBICFLAG_IN_SLOWSTART;		cubic_does_slow_start(ccv, cubic_data);
newreno_cc_ack_received(ccv, type);
} else {		} else {
		if (cubic_data->flags & CUBICFLAG_HYSTART_IN_CSS) {
		/*
		* We have slipped into CA with
		* CSS active. Deactivate all.
		*/
		/* Turn off the CSS flag */
		cubic_data->flags &= ~CUBICFLAG_HYSTART_IN_CSS;
		/* Disable use of CSS in the future except long idle */
		cubic_data->flags &= ~CUBICFLAG_HYSTART_ENABLED;
		cubic_log_hystart_event(ccv, cubic_data, 11, CCV(ccv, snd_ssthresh));
		}
if ((cubic_data->flags & CUBICFLAG_RTO_EVENT) &&		if ((cubic_data->flags & CUBICFLAG_RTO_EVENT) &&
(cubic_data->flags & CUBICFLAG_IN_SLOWSTART)) {		(cubic_data->flags & CUBICFLAG_IN_SLOWSTART)) {
/* RFC8312 Section 4.7 */		/* RFC8312 Section 4.7 */
cubic_data->flags &= ~(CUBICFLAG_RTO_EVENT \|		cubic_data->flags &= ~(CUBICFLAG_RTO_EVENT \|
CUBICFLAG_IN_SLOWSTART);		CUBICFLAG_IN_SLOWSTART);
cubic_data->max_cwnd = CCV(ccv, snd_cwnd);		cubic_data->max_cwnd = CCV(ccv, snd_cwnd);
cubic_data->K = 0;		cubic_data->K = 0;
} else if (cubic_data->flags & (CUBICFLAG_IN_SLOWSTART \|		} else if (cubic_data->flags & (CUBICFLAG_IN_SLOWSTART \|
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cubic_after_idle(struct cc_var *ccv)		cubic_after_idle(struct cc_var *ccv)
{		{
struct cubic *cubic_data;		struct cubic *cubic_data;

cubic_data = ccv->cc_data;		cubic_data = ccv->cc_data;

cubic_data->max_cwnd = ulmax(cubic_data->max_cwnd, CCV(ccv, snd_cwnd));		cubic_data->max_cwnd = ulmax(cubic_data->max_cwnd, CCV(ccv, snd_cwnd));
cubic_data->K = cubic_k(cubic_data->max_cwnd / CCV(ccv, t_maxseg));		cubic_data->K = cubic_k(cubic_data->max_cwnd / CCV(ccv, t_maxseg));
		if ((cubic_data->flags & CUBICFLAG_HYSTART_ENABLED) == 0) {
		/*
		* Re-enable hystart if we have been idle.
		*/
		cubic_data->flags &= ~CUBICFLAG_HYSTART_IN_CSS;
		cubic_data->flags \|= CUBICFLAG_HYSTART_ENABLED;
		cubic_log_hystart_event(ccv, cubic_data, 12, CCV(ccv, snd_ssthresh));
		}
newreno_cc_after_idle(ccv);		newreno_cc_after_idle(ccv);
cubic_data->t_last_cong = ticks;		cubic_data->t_last_cong = ticks;
}		}

static void		static void
cubic_cb_destroy(struct cc_var *ccv)		cubic_cb_destroy(struct cc_var *ccv)
{		{
free(ccv->cc_data, M_CC_MEM);		free(ccv->cc_data, M_CC_MEM);
Show All 19 Lines	if (ptr == NULL) {
cubic_data = ptr;		cubic_data = ptr;

/* Init some key variables with sensible defaults. */		/* Init some key variables with sensible defaults. */
cubic_data->t_last_cong = ticks;		cubic_data->t_last_cong = ticks;
cubic_data->min_rtt_ticks = TCPTV_SRTTBASE;		cubic_data->min_rtt_ticks = TCPTV_SRTTBASE;
cubic_data->mean_rtt_ticks = 1;		cubic_data->mean_rtt_ticks = 1;

ccv->cc_data = cubic_data;		ccv->cc_data = cubic_data;
		cubic_data->flags = CUBICFLAG_HYSTART_ENABLED;
		/* At init set both to infinity */
		cubic_data->css_lastround_minrtt = 0xffffffff;
		cubic_data->css_current_round_minrtt = 0xffffffff;
		cubic_data->css_current_round = 0;
		cubic_data->css_baseline_minrtt = 0xffffffff;
		cubic_data->css_rttsample_count = 0;
		cubic_data->css_entered_at_round = 0;
		cubic_data->css_fas_at_css_entry = 0;
		cubic_data->css_lowrtt_fas = 0;
		cubic_data->css_last_fas = 0;

return (0);		return (0);
}		}

/*		/*
* Perform any necessary tasks before we enter congestion recovery.		* Perform any necessary tasks before we enter congestion recovery.
*/		*/
static void		static void
cubic_cong_signal(struct cc_var *ccv, uint32_t type)		cubic_cong_signal(struct cc_var *ccv, uint32_t type)
{		{
struct cubic *cubic_data;		struct cubic *cubic_data;
u_int mss;		u_int mss;

cubic_data = ccv->cc_data;		cubic_data = ccv->cc_data;
mss = tcp_maxseg(ccv->ccvc.tcp);		mss = tcp_maxseg(ccv->ccvc.tcp);

switch (type) {		switch (type) {
case CC_NDUPACK:		case CC_NDUPACK:
		if (cubic_data->flags & CUBICFLAG_HYSTART_ENABLED) {
		/* Make sure the flags are all off we had a loss */
		cubic_data->flags &= ~CUBICFLAG_HYSTART_ENABLED;
		cubic_data->flags &= ~CUBICFLAG_HYSTART_IN_CSS;
		cubic_log_hystart_event(ccv, cubic_data, 10, CCV(ccv, snd_ssthresh));
		}
if (!IN_FASTRECOVERY(CCV(ccv, t_flags))) {		if (!IN_FASTRECOVERY(CCV(ccv, t_flags))) {
if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) {		if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) {
cubic_ssthresh_update(ccv, mss);		cubic_ssthresh_update(ccv, mss);
cubic_data->flags \|= CUBICFLAG_CONG_EVENT;		cubic_data->flags \|= CUBICFLAG_CONG_EVENT;
cubic_data->t_last_cong = ticks;		cubic_data->t_last_cong = ticks;
cubic_data->K = cubic_k(cubic_data->max_cwnd / mss);		cubic_data->K = cubic_k(cubic_data->max_cwnd / mss);
}		}
ENTER_RECOVERY(CCV(ccv, t_flags));		ENTER_RECOVERY(CCV(ccv, t_flags));
}		}
break;		break;

case CC_ECN:		case CC_ECN:
		if (cubic_data->flags & CUBICFLAG_HYSTART_ENABLED) {
		/* Make sure the flags are all off we had a loss */
		cubic_data->flags &= ~CUBICFLAG_HYSTART_ENABLED;
		cubic_data->flags &= ~CUBICFLAG_HYSTART_IN_CSS;
		cubic_log_hystart_event(ccv, cubic_data, 9, CCV(ccv, snd_ssthresh));
		}
if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) {		if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) {
cubic_ssthresh_update(ccv, mss);		cubic_ssthresh_update(ccv, mss);
cubic_data->flags \|= CUBICFLAG_CONG_EVENT;		cubic_data->flags \|= CUBICFLAG_CONG_EVENT;
cubic_data->t_last_cong = ticks;		cubic_data->t_last_cong = ticks;
cubic_data->K = cubic_k(cubic_data->max_cwnd / mss);		cubic_data->K = cubic_k(cubic_data->max_cwnd / mss);
CCV(ccv, snd_cwnd) = CCV(ccv, snd_ssthresh);		CCV(ccv, snd_cwnd) = CCV(ccv, snd_ssthresh);
ENTER_CONGRECOVERY(CCV(ccv, t_flags));		ENTER_CONGRECOVERY(CCV(ccv, t_flags));
}		}
▲ Show 20 Lines • Show All 166 Lines • ▼ Show 20 Lines	if ((cubic_data->flags & CUBICFLAG_CONG_EVENT) == 0) {
ssthresh = cwnd >> 1;		ssthresh = cwnd >> 1;
cubic_data->max_cwnd = ((uint64_t)cwnd *		cubic_data->max_cwnd = ((uint64_t)cwnd *
CUBIC_BETA) >> CUBIC_SHIFT;		CUBIC_BETA) >> CUBIC_SHIFT;
} else {		} else {
ssthresh = ((uint64_t)cwnd *		ssthresh = ((uint64_t)cwnd *
CUBIC_BETA) >> CUBIC_SHIFT;		CUBIC_BETA) >> CUBIC_SHIFT;
}		}
CCV(ccv, snd_ssthresh) = max(ssthresh, 2 * maxseg);		CCV(ccv, snd_ssthresh) = max(ssthresh, 2 * maxseg);
		}

		static void
		cubic_rttsample(struct cc_var *ccv, uint32_t usec_rtt, uint32_t rxtcnt, uint32_t fas)
		{
		struct cubic *cubicd;

		cubicd = ccv->cc_data;
		if (rxtcnt > 1) {
		/*
		* Only look at RTT's that are non-ambiguous.
		*/
		return;
		}
		cubicd->css_rttsample_count++;
		cubicd->css_last_fas = fas;
		if (cubicd->css_current_round_minrtt > usec_rtt) {
		cubicd->css_current_round_minrtt = usec_rtt;
		cubicd->css_lowrtt_fas = cubicd->css_last_fas;
		}
		if ((cubicd->css_rttsample_count >= hystart_n_rttsamples) &&
		(cubicd->css_current_round_minrtt != 0xffffffff) &&
		(cubicd->css_lastround_minrtt != 0xffffffff)) {
		/*
		* We were in CSS and the RTT is now less, we
		* entered CSS erroneously.
		*/
		cubicd->flags &= ~CUBICFLAG_HYSTART_IN_CSS;
		cubic_log_hystart_event(ccv, cubicd, 8, cubicd->css_baseline_minrtt);
		cubicd->css_baseline_minrtt = 0xffffffff;
		}
		if (cubicd->flags & CUBICFLAG_HYSTART_ENABLED)
		cubic_log_hystart_event(ccv, cubicd, 5, usec_rtt);
		}

		static void
		cubic_newround(struct cc_var *ccv, uint32_t round_cnt)
		{
		struct cubic *cubicd;

		cubicd = ccv->cc_data;
		/* We have entered a new round */
		cubicd->css_lastround_minrtt = cubicd->css_current_round_minrtt;
		cubicd->css_current_round_minrtt = 0xffffffff;
		cubicd->css_rttsample_count = 0;
		cubicd->css_current_round = round_cnt;
		if ((cubicd->flags & CUBICFLAG_HYSTART_IN_CSS) &&
		((round_cnt - cubicd->css_entered_at_round) >= hystart_css_rounds)) {
		/* Enter CA */
		if (ccv->flags & CCF_HYSTART_CAN_SH_CWND) {
		/*
		* We engage more than snd_ssthresh, engage
		* the brakes!! Though we will stay in SS to
		* creep back up again, so lets leave CSS active
		* and give us hystart_css_rounds more rounds.
		*/
		if (ccv->flags & CCF_HYSTART_CONS_SSTH) {
		CCV(ccv, snd_ssthresh) = ((cubicd->css_lowrtt_fas + cubicd->css_fas_at_css_entry) / 2);
		} else {
		CCV(ccv, snd_ssthresh) = cubicd->css_lowrtt_fas;
		}
		CCV(ccv, snd_cwnd) = cubicd->css_fas_at_css_entry;
		cubicd->css_entered_at_round = round_cnt;
		} else {
		CCV(ccv, snd_ssthresh) = CCV(ccv, snd_cwnd);
		/* Turn off the CSS flag */
		cubicd->flags &= ~CUBICFLAG_HYSTART_IN_CSS;
		/* Disable use of CSS in the future except long idle */
		cubicd->flags &= ~CUBICFLAG_HYSTART_ENABLED;
		}
		cubic_log_hystart_event(ccv, cubicd, 6, CCV(ccv, snd_ssthresh));
		}
		if (cubicd->flags & CUBICFLAG_HYSTART_ENABLED)
		cubic_log_hystart_event(ccv, cubicd, 4, round_cnt);
}		}

DECLARE_CC_MODULE(cubic, &cubic_cc_algo);		DECLARE_CC_MODULE(cubic, &cubic_cc_algo);
MODULE_VERSION(cubic, 2);		MODULE_VERSION(cubic, 2);