git: a9696510f5ca - main - tcp: Add hystart++ to our cubic implementation.
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Date: Mon, 07 Feb 2022 11:40:27 UTC
The branch main has been updated by rrs:
URL: https://cgit.FreeBSD.org/src/commit/?id=a9696510f5caef4a7c525fcf4359597798829350
commit a9696510f5caef4a7c525fcf4359597798829350
Author: Randall Stewart <rrs@FreeBSD.org>
AuthorDate: 2022-02-07 11:37:46 +0000
Commit: Randall Stewart <rrs@FreeBSD.org>
CommitDate: 2022-02-07 11:37:46 +0000
tcp: Add hystart++ to our cubic implementation.
As promised to the transport call on 11/4/22 here is an implementation
of hystart++ for cubic. It also cleans up the tcp_congestion function
to have a better name. Common variables are moved into the general
cc.h structure so that both cubic and newreno can use them for
hystart++
Reviewed by: Michael Tuexen, Richard Scheffenegger
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D33035
---
share/man/man4/cc_newreno.4 | 39 +----
share/man/man4/mod_cc.4 | 25 +++-
sys/netinet/cc/cc.c | 41 ++++++
sys/netinet/cc/cc.h | 12 ++
sys/netinet/cc/cc_cubic.c | 291 +++++++++++++++++++++++++++++++++-----
sys/netinet/cc/cc_cubic.h | 49 +++++++
sys/netinet/cc/cc_newreno.c | 122 +++++-----------
sys/netinet/cc/cc_newreno.h | 4 -
sys/netinet/tcp_stacks/rack.c | 105 +++++++++-----
sys/netinet/tcp_stacks/tcp_rack.h | 8 ++
10 files changed, 492 insertions(+), 204 deletions(-)
diff --git a/share/man/man4/cc_newreno.4 b/share/man/man4/cc_newreno.4
index 1c4f4a39cb36..71d3a239ecd1 100644
--- a/share/man/man4/cc_newreno.4
+++ b/share/man/man4/cc_newreno.4
@@ -75,21 +75,10 @@ the congestion window in response to an ECN congestion signal when
.Va net.inet.tcp.cc.abe=1
per: cwnd = (cwnd * CC_NEWRENO_BETA_ECN) / 100.
Default is 80.
-.It Va CC_NEWRENO_ENABLE_HYSTART
-will enable or disable the application of Hystart++.
-The current implementation allows the values 0, 1, 2 and 3.
-A value of 0 (the default) disables the use of Hystart++.
-Setting the value to 1 enables Hystart++.
-Setting the value to 2 enables Hystart++ but also will cause, on exit from Hystart++'s CSS, to
-set the cwnd to the value of where the increase in RTT first began as
-well as setting ssthresh to the flight at send when we exit CSS.
-Setting a value of 3 will keep the setting of the cwnd the same as 2, but will cause ssthresh
-to be set to the average value between the lowest fas rtt (the value cwnd is
-set to) and the fas value at exit of CSS.
.PP
Note that currently the only way to enable
hystart++ is to enable it via socket option.
-When enabling it a value of 1 will enable precise internet-draft behavior
+When enabling it a value of 1 will enable precise internet-draft (version 4) behavior
(subject to any MIB variable settings), other setting (2 and 3) are experimental.
.El
.PP
@@ -120,32 +109,6 @@ the congestion window in response to an ECN congestion signal when
.Va net.inet.tcp.cc.abe=1
per: cwnd = (cwnd * beta_ecn) / 100.
Default is 80.
-.It Va hystartplusplus.bblogs
-This boolean controls if black box logging will be done for hystart++ events. If set
-to zero (the default) no logging is performed.
-If set to one then black box logs will be generated on all hystart++ events.
-.It Va hystartplusplus.css_rounds
-This value controls the number of rounds that CSS runs for.
-The default value matches the current internet-draft of 5.
-.It Va hystartplusplus.css_growth_div
-This value controls the divisor applied to slowstart during CSS.
-The default value matches the current internet-draft of 4.
-.It Va hystartplusplus.n_rttsamples
-This value controls how many rtt samples must be collected in each round for
-hystart++ to be active.
-The default value matches the current internet-draft of 8.
-.It Va hystartplusplus.maxrtt_thresh
-This value controls the maximum rtt variance clamp when considering if CSS is needed.
-The default value matches the current internet-draft of 16000 (in microseconds).
-For further explanation please see the internet-draft.
-.It Va hystartplusplus.minrtt_thresh
-This value controls the minimum rtt variance clamp when considering if CSS is needed.
-The default value matches the current internet-draft of 4000 (in microseconds).
-For further explanation please see the internet-draft.
-.It Va hystartplusplus.lowcwnd
-This value controls what is the lowest congestion window that the tcp
-stack must be at before hystart++ engages.
-The default value matches the current internet-draft of 16.
.El
.Sh SEE ALSO
.Xr cc_cdg 4 ,
diff --git a/share/man/man4/mod_cc.4 b/share/man/man4/mod_cc.4
index 84edf0b2a8ed..ddc7440a4ca7 100644
--- a/share/man/man4/mod_cc.4
+++ b/share/man/man4/mod_cc.4
@@ -83,7 +83,7 @@ The framework exposes the following variables in the
branch of the
.Xr sysctl 3
MIB:
-.Bl -tag -width ".Va abe_frlossreduce"
+.Bl -tag -width ".Va hystartplusplus.css_growth_div"
.It Va available
Read-only list of currently available congestion control algorithms by name.
.It Va algorithm
@@ -102,10 +102,33 @@ support for ABE and for configuration details.
.It Va abe_frlossreduce
If non-zero, apply standard beta instead of ABE-beta during ECN-signalled
congestion recovery episodes if loss also needs to be repaired.
+.It Va hystartplusplus.bblogs
+This boolean controls if black box logging will be done for hystart++ events.
+If set to zero (the default) no logging is performed.
+If set to one then black box logs will be generated on all hystart++ events.
+.It Va hystartplusplus.css_rounds
+This value controls the number of rounds that CSS runs for.
+The default value matches the current internet-draft of 5.
+.It Va hystartplusplus.css_growth_div
+This value controls the divisor applied to slowstart during CSS.
+The default value matches the current internet-draft of 4.
+.It Va hystartplusplus.n_rttsamples
+This value controls how many rtt samples must be collected in each round for
+hystart++ to be active.
+The default value matches the current internet-draft of 8.
+.It Va hystartplusplus.maxrtt_thresh
+This value controls the maximum rtt variance clamp when considering if CSS is needed.
+The default value matches the current internet-draft of 16000 (in microseconds).
+For further explanation please see the internet-draft.
+.It Va hystartplusplus.minrtt_thresh
+This value controls the minimum rtt variance clamp when considering if CSS is needed.
+The default value matches the current internet-draft of 4000 (in microseconds).
+For further explanation please see the internet-draft.
.El
.Pp
Each congestion control module may also expose other MIB variables
to control their behaviour.
+Note that both newreno and cubic now support hystart++ based on the version 3 of the internet-draft.
.Sh Kernel Configuration
.Pp
All of the available congestion control modules may also be loaded
diff --git a/sys/netinet/cc/cc.c b/sys/netinet/cc/cc.c
index bcda9276d4d9..647ecb47f18d 100644
--- a/sys/netinet/cc/cc.c
+++ b/sys/netinet/cc/cc.c
@@ -84,6 +84,13 @@ __FBSDID("$FreeBSD$");
#define CC_DEFAULT "newreno"
#endif
+uint32_t hystart_minrtt_thresh = 4000;
+uint32_t hystart_maxrtt_thresh = 16000;
+uint32_t hystart_n_rttsamples = 8;
+uint32_t hystart_css_growth_div = 4;
+uint32_t hystart_css_rounds = 5;
+uint32_t hystart_bblogs = 0;
+
MALLOC_DEFINE(M_CC_MEM, "CC Mem", "Congestion Control State memory");
/*
@@ -582,6 +589,40 @@ SYSCTL_PROC(_net_inet_tcp_cc, OID_AUTO, available,
NULL, 0, cc_list_available, "A",
"List available congestion control algorithms");
+SYSCTL_NODE(_net_inet_tcp_cc, OID_AUTO, hystartplusplus,
+ CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
+ "New Reno related HyStart++ settings");
+
+SYSCTL_UINT(_net_inet_tcp_cc_hystartplusplus, OID_AUTO, minrtt_thresh,
+ CTLFLAG_RW,
+ &hystart_minrtt_thresh, 4000,
+ "HyStarts++ minimum RTT thresh used in clamp (in microseconds)");
+
+SYSCTL_UINT(_net_inet_tcp_cc_hystartplusplus, OID_AUTO, maxrtt_thresh,
+ CTLFLAG_RW,
+ &hystart_maxrtt_thresh, 16000,
+ "HyStarts++ maximum RTT thresh used in clamp (in microseconds)");
+
+SYSCTL_UINT(_net_inet_tcp_cc_hystartplusplus, OID_AUTO, n_rttsamples,
+ CTLFLAG_RW,
+ &hystart_n_rttsamples, 8,
+ "The number of RTT samples that must be seen to consider HyStart++");
+
+SYSCTL_UINT(_net_inet_tcp_cc_hystartplusplus, OID_AUTO, css_growth_div,
+ CTLFLAG_RW,
+ &hystart_css_growth_div, 4,
+ "The divisor to the growth when in Hystart++ CSS");
+
+SYSCTL_UINT(_net_inet_tcp_cc_hystartplusplus, OID_AUTO, css_rounds,
+ CTLFLAG_RW,
+ &hystart_css_rounds, 5,
+ "The number of rounds HyStart++ lasts in CSS before falling to CA");
+
+SYSCTL_UINT(_net_inet_tcp_cc_hystartplusplus, OID_AUTO, bblogs,
+ CTLFLAG_RW,
+ &hystart_bblogs, 0,
+ "Do we enable HyStart++ Black Box logs to be generated if BB logging is on");
+
VNET_DEFINE(int, cc_do_abe) = 0;
SYSCTL_INT(_net_inet_tcp_cc, OID_AUTO, abe, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(cc_do_abe), 0,
diff --git a/sys/netinet/cc/cc.h b/sys/netinet/cc/cc.h
index 4282f0585bbd..6f942da7aa83 100644
--- a/sys/netinet/cc/cc.h
+++ b/sys/netinet/cc/cc.h
@@ -72,6 +72,15 @@ VNET_DECLARE(int, cc_abe_frlossreduce);
/* Define the new net.inet.tcp.cc sysctl tree. */
SYSCTL_DECL(_net_inet_tcp_cc);
+/* For CC modules that use hystart++ */
+extern uint32_t hystart_lowcwnd;
+extern uint32_t hystart_minrtt_thresh;
+extern uint32_t hystart_maxrtt_thresh;
+extern uint32_t hystart_n_rttsamples;
+extern uint32_t hystart_css_growth_div;
+extern uint32_t hystart_css_rounds;
+extern uint32_t hystart_bblogs;
+
/* CC housekeeping functions. */
int cc_register_algo(struct cc_algo *add_cc);
int cc_deregister_algo(struct cc_algo *remove_cc);
@@ -106,6 +115,9 @@ struct cc_var {
#define CCF_CHG_MAX_CWND 0x0080 /* Cubic max_cwnd changed, for K */
#define CCF_USR_IWND 0x0100 /* User specified initial window */
#define CCF_USR_IWND_INIT_NSEG 0x0200 /* Convert segs to bytes on conn init */
+#define CCF_HYSTART_ALLOWED 0x0400 /* If the CC supports it Hystart is allowed */
+#define CCF_HYSTART_CAN_SH_CWND 0x0800 /* Can hystart when going CSS -> CA slam the cwnd */
+#define CCF_HYSTART_CONS_SSTH 0x1000 /* Should hystart use the more conservative ssthresh */
/* ACK types passed to the ack_received() hook. */
#define CC_ACK 0x0001 /* Regular in sequence ACK. */
diff --git a/sys/netinet/cc/cc_cubic.c b/sys/netinet/cc/cc_cubic.c
index a4146423b0ae..e7d86a25156a 100644
--- a/sys/netinet/cc/cc_cubic.c
+++ b/sys/netinet/cc/cc_cubic.c
@@ -70,6 +70,8 @@ __FBSDID("$FreeBSD$");
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.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_cubic.h>
#include <netinet/cc/cc_module.h>
@@ -85,39 +87,9 @@ static void cubic_record_rtt(struct cc_var *ccv);
static void cubic_ssthresh_update(struct cc_var *ccv, uint32_t maxseg);
static void cubic_after_idle(struct cc_var *ccv);
static size_t cubic_data_sz(void);
-
-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;
-};
+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 cc_algo cubic_cc_algo = {
.name = "cubic",
@@ -129,9 +101,140 @@ struct cc_algo cubic_cc_algo = {
.mod_init = cubic_mod_init,
.post_recovery = cubic_post_recovery,
.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
+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);
+ 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)
{
@@ -151,9 +254,19 @@ cubic_ack_received(struct cc_var *ccv, uint16_t type)
/* Use the logic in NewReno ack_received() for slow start. */
if (CCV(ccv, snd_cwnd) <= CCV(ccv, snd_ssthresh) ||
cubic_data->min_rtt_ticks == TCPTV_SRTTBASE) {
- cubic_data->flags |= CUBICFLAG_IN_SLOWSTART;
- newreno_cc_ack_received(ccv, type);
+ cubic_does_slow_start(ccv, cubic_data);
} 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) &&
(cubic_data->flags & CUBICFLAG_IN_SLOWSTART)) {
/* RFC8312 Section 4.7 */
@@ -245,7 +358,14 @@ cubic_after_idle(struct cc_var *ccv)
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));
-
+ 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);
cubic_data->t_last_cong = ticks;
}
@@ -281,6 +401,17 @@ cubic_cb_init(struct cc_var *ccv, void *ptr)
cubic_data->mean_rtt_ticks = 1;
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);
}
@@ -299,6 +430,12 @@ cubic_cong_signal(struct cc_var *ccv, uint32_t type)
switch (type) {
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_CONGRECOVERY(CCV(ccv, t_flags))) {
cubic_ssthresh_update(ccv, mss);
@@ -311,6 +448,12 @@ cubic_cong_signal(struct cc_var *ccv, uint32_t type)
break;
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))) {
cubic_ssthresh_update(ccv, mss);
cubic_data->flags |= CUBICFLAG_CONG_EVENT;
@@ -495,5 +638,79 @@ cubic_ssthresh_update(struct cc_var *ccv, uint32_t 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);
MODULE_VERSION(cubic, 2);
diff --git a/sys/netinet/cc/cc_cubic.h b/sys/netinet/cc/cc_cubic.h
index 13681aae793c..2042590182fc 100644
--- a/sys/netinet/cc/cc_cubic.h
+++ b/sys/netinet/cc/cc_cubic.h
@@ -78,6 +78,55 @@
*/
#define CUBED_ROOT_MAX_ULONG 448845
+/* Flags used in the cubic structure */
+#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 */
+#define CUBICFLAG_HYSTART_ENABLED 0x00000010 /* Hystart++ is enabled */
+#define CUBICFLAG_HYSTART_IN_CSS 0x00000020 /* We are in Hystart++ CSS */
+
+/* Kernel only bits */
+#ifdef _KERNEL
+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;
+ /* 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;
+ uint32_t css_baseline_minrtt;
+ uint32_t css_current_round_minrtt;
+ uint32_t css_lastround_minrtt;
+ uint32_t css_rttsample_count;
+ uint32_t css_entered_at_round;
+ uint32_t css_current_round;
+ uint32_t css_fas_at_css_entry;
+ uint32_t css_lowrtt_fas;
+ uint32_t css_last_fas;
+};
+#endif
+
/* Userland only bits. */
#ifndef _KERNEL
diff --git a/sys/netinet/cc/cc_newreno.c b/sys/netinet/cc/cc_newreno.c
index 3280e270ede3..06b53d76d8e9 100644
--- a/sys/netinet/cc/cc_newreno.c
+++ b/sys/netinet/cc/cc_newreno.c
@@ -116,14 +116,6 @@ struct cc_algo newreno_cc_algo = {
.cc_data_sz = newreno_data_sz,
};
-static uint32_t hystart_lowcwnd = 16;
-static uint32_t hystart_minrtt_thresh = 4000;
-static uint32_t hystart_maxrtt_thresh = 16000;
-static uint32_t hystart_n_rttsamples = 8;
-static uint32_t hystart_css_growth_div = 4;
-static uint32_t hystart_css_rounds = 5;
-static uint32_t hystart_bblogs = 0;
-
static void
newreno_log_hystart_event(struct cc_var *ccv, struct newreno *nreno, uint8_t mod, uint32_t flex1)
{
@@ -137,6 +129,10 @@ newreno_log_hystart_event(struct cc_var *ccv, struct newreno *nreno, uint8_t mod
* 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;
@@ -162,6 +158,7 @@ newreno_log_hystart_event(struct cc_var *ccv, struct newreno *nreno, uint8_t mod
log.u_bbr.lt_epoch = nreno->css_fas_at_css_entry;
log.u_bbr.pkts_out = nreno->css_last_fas;
log.u_bbr.delivered = nreno->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,
@@ -265,6 +262,7 @@ newreno_ack_received(struct cc_var *ccv, uint16_t type)
nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_IN_CSS;
/* Disable use of CSS in the future except long idle */
nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_ENABLED;
+ newreno_log_hystart_event(ccv, nreno, 11, CCV(ccv, snd_ssthresh));
}
if (V_tcp_do_rfc3465) {
if (ccv->flags & CCF_ABC_SENTAWND)
@@ -290,7 +288,7 @@ newreno_ack_received(struct cc_var *ccv, uint16_t type)
abc_val = ccv->labc;
else
abc_val = V_tcp_abc_l_var;
- if ((nreno->newreno_flags & CC_NEWRENO_HYSTART_ALLOWED) &&
+ if ((ccv->flags & CCF_HYSTART_ALLOWED) &&
(nreno->newreno_flags & CC_NEWRENO_HYSTART_ENABLED) &&
((nreno->newreno_flags & CC_NEWRENO_HYSTART_IN_CSS) == 0)) {
/*
@@ -299,8 +297,8 @@ newreno_ack_received(struct cc_var *ccv, uint16_t type)
* if we need to go into CSS.
*/
if ((nreno->css_rttsample_count >= hystart_n_rttsamples) &&
- (CCV(ccv, snd_cwnd) >
- (hystart_lowcwnd * tcp_fixed_maxseg(ccv->ccvc.tcp)))) {
+ (nreno->css_current_round_minrtt != 0xffffffff) &&
+ (nreno->css_lastround_minrtt != 0xffffffff)) {
uint32_t rtt_thresh;
/* Clamp (minrtt_thresh, lastround/8, maxrtt_thresh) */
@@ -314,6 +312,13 @@ newreno_ack_received(struct cc_var *ccv, uint16_t type)
/* Enter CSS */
nreno->newreno_flags |= CC_NEWRENO_HYSTART_IN_CSS;
nreno->css_fas_at_css_entry = nreno->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.
+ */
nreno->css_baseline_minrtt = nreno->css_current_round_minrtt;
nreno->css_entered_at_round = nreno->css_current_round;
newreno_log_hystart_event(ccv, nreno, 2, rtt_thresh);
@@ -348,14 +353,12 @@ newreno_after_idle(struct cc_var *ccv)
nreno = ccv->cc_data;
newreno_cc_after_idle(ccv);
if ((nreno->newreno_flags & CC_NEWRENO_HYSTART_ENABLED) == 0) {
- if (CCV(ccv, snd_cwnd) <= (hystart_lowcwnd * tcp_fixed_maxseg(ccv->ccvc.tcp))) {
- /*
- * Re-enable hystart if our cwnd has fallen below
- * the hystart lowcwnd point.
- */
- nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_IN_CSS;
- nreno->newreno_flags |= CC_NEWRENO_HYSTART_ENABLED;
- }
+ /*
+ * Re-enable hystart if we have been idle.
+ */
+ nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_IN_CSS;
+ nreno->newreno_flags |= CC_NEWRENO_HYSTART_ENABLED;
+ newreno_log_hystart_event(ccv, nreno, 12, CCV(ccv, snd_ssthresh));
}
}
@@ -400,6 +403,7 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
/* Make sure the flags are all off we had a loss */
nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_ENABLED;
nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_IN_CSS;
+ newreno_log_hystart_event(ccv, nreno, 10, CCV(ccv, snd_ssthresh));
}
if (!IN_FASTRECOVERY(CCV(ccv, t_flags))) {
if (IN_CONGRECOVERY(CCV(ccv, t_flags) &&
@@ -418,6 +422,7 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
/* Make sure the flags are all off we had a loss */
nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_ENABLED;
nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_IN_CSS;
+ newreno_log_hystart_event(ccv, nreno, 9, CCV(ccv, snd_ssthresh));
}
if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) {
CCV(ccv, snd_ssthresh) = cwin;
@@ -460,18 +465,6 @@ newreno_ctl_output(struct cc_var *ccv, struct sockopt *sopt, void *buf)
nreno->beta_ecn = opt->val;
nreno->newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
break;
- case CC_NEWRENO_ENABLE_HYSTART:
- /* Allow hystart on this connection */
- if (opt->val != 0) {
- nreno->newreno_flags |= CC_NEWRENO_HYSTART_ALLOWED;
- if (opt->val > 1)
- nreno->newreno_flags |= CC_NEWRENO_HYSTART_CAN_SH_CWND;
- if (opt->val > 2)
- nreno->newreno_flags |= CC_NEWRENO_HYSTART_CONS_SSTH;
- } else
- nreno->newreno_flags &= ~(CC_NEWRENO_HYSTART_ALLOWED|CC_NEWRENO_HYSTART_CAN_SH_CWND|CC_NEWRENO_HYSTART_CONS_SSTH);
- newreno_log_hystart_event(ccv, nreno, 7, opt->val);
- break;
default:
return (ENOPROTOOPT);
}
@@ -486,17 +479,6 @@ newreno_ctl_output(struct cc_var *ccv, struct sockopt *sopt, void *buf)
opt->val = (nreno == NULL) ?
V_newreno_beta_ecn : nreno->beta_ecn;
break;
- case CC_NEWRENO_ENABLE_HYSTART:
- if (nreno->newreno_flags & CC_NEWRENO_HYSTART_ALLOWED) {
- if (nreno->newreno_flags & CC_NEWRENO_HYSTART_CONS_SSTH)
- opt->val = 3;
- else if (nreno->newreno_flags & CC_NEWRENO_HYSTART_CAN_SH_CWND)
- opt->val = 2;
- else
- opt->val = 1;
- } else
- opt->val = 0;
- break;
default:
return (ENOPROTOOPT);
}
@@ -542,14 +524,14 @@ newreno_newround(struct cc_var *ccv, uint32_t round_cnt)
if ((nreno->newreno_flags & CC_NEWRENO_HYSTART_IN_CSS) &&
((round_cnt - nreno->css_entered_at_round) >= hystart_css_rounds)) {
/* Enter CA */
- if (nreno->newreno_flags & CC_NEWRENO_HYSTART_CAN_SH_CWND) {
+ 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 (nreno->newreno_flags & CC_NEWRENO_HYSTART_CONS_SSTH) {
+ if (ccv->flags & CCF_HYSTART_CONS_SSTH) {
CCV(ccv, snd_ssthresh) = ((nreno->css_lowrtt_fas + nreno->css_fas_at_css_entry) / 2);
} else {
CCV(ccv, snd_ssthresh) = nreno->css_lowrtt_fas;
@@ -565,7 +547,8 @@ newreno_newround(struct cc_var *ccv, uint32_t round_cnt)
}
newreno_log_hystart_event(ccv, nreno, 6, CCV(ccv, snd_ssthresh));
}
- newreno_log_hystart_event(ccv, nreno, 4, round_cnt);
+ if (nreno->newreno_flags & CC_NEWRENO_HYSTART_ENABLED)
+ newreno_log_hystart_event(ccv, nreno, 4, round_cnt);
}
static void
@@ -586,9 +569,9 @@ newreno_rttsample(struct cc_var *ccv, uint32_t usec_rtt, uint32_t rxtcnt, uint32
nreno->css_current_round_minrtt = usec_rtt;
nreno->css_lowrtt_fas = nreno->css_last_fas;
}
- if ((nreno->newreno_flags & CC_NEWRENO_HYSTART_IN_CSS) &&
- (nreno->css_rttsample_count >= hystart_n_rttsamples) &&
- (nreno->css_baseline_minrtt > nreno->css_current_round_minrtt)) {
+ if ((nreno->css_rttsample_count >= hystart_n_rttsamples) &&
+ (nreno->css_current_round_minrtt != 0xffffffff) &&
+ (nreno->css_lastround_minrtt != 0xffffffff)) {
/*
* We were in CSS and the RTT is now less, we
* entered CSS erroneously.
@@ -597,7 +580,8 @@ newreno_rttsample(struct cc_var *ccv, uint32_t usec_rtt, uint32_t rxtcnt, uint32
newreno_log_hystart_event(ccv, nreno, 8, nreno->css_baseline_minrtt);
nreno->css_baseline_minrtt = 0xffffffff;
}
- newreno_log_hystart_event(ccv, nreno, 5, usec_rtt);
+ if (nreno->newreno_flags & CC_NEWRENO_HYSTART_ENABLED)
+ newreno_log_hystart_event(ccv, nreno, 5, usec_rtt);
}
SYSCTL_DECL(_net_inet_tcp_cc_newreno);
@@ -615,45 +599,5 @@ SYSCTL_PROC(_net_inet_tcp_cc_newreno, OID_AUTO, beta_ecn,
&VNET_NAME(newreno_beta_ecn), 3, &newreno_beta_handler, "IU",
"New Reno beta ecn, specified as number between 1 and 100");
-SYSCTL_NODE(_net_inet_tcp_cc_newreno, OID_AUTO, hystartplusplus,
- CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
- "New Reno related HyStart++ settings");
-
-SYSCTL_UINT(_net_inet_tcp_cc_newreno_hystartplusplus, OID_AUTO, lowcwnd,
- CTLFLAG_RW,
- &hystart_lowcwnd, 16,
- "The number of MSS in the CWND before HyStart++ is active");
-
-SYSCTL_UINT(_net_inet_tcp_cc_newreno_hystartplusplus, OID_AUTO, minrtt_thresh,
- CTLFLAG_RW,
- &hystart_minrtt_thresh, 4000,
- "HyStarts++ minimum RTT thresh used in clamp (in microseconds)");
-
-SYSCTL_UINT(_net_inet_tcp_cc_newreno_hystartplusplus, OID_AUTO, maxrtt_thresh,
- CTLFLAG_RW,
- &hystart_maxrtt_thresh, 16000,
- "HyStarts++ maximum RTT thresh used in clamp (in microseconds)");
-
-SYSCTL_UINT(_net_inet_tcp_cc_newreno_hystartplusplus, OID_AUTO, n_rttsamples,
- CTLFLAG_RW,
- &hystart_n_rttsamples, 8,
- "The number of RTT samples that must be seen to consider HyStart++");
-
-SYSCTL_UINT(_net_inet_tcp_cc_newreno_hystartplusplus, OID_AUTO, css_growth_div,
- CTLFLAG_RW,
- &hystart_css_growth_div, 4,
- "The divisor to the growth when in Hystart++ CSS");
-
-SYSCTL_UINT(_net_inet_tcp_cc_newreno_hystartplusplus, OID_AUTO, css_rounds,
- CTLFLAG_RW,
- &hystart_css_rounds, 5,
- "The number of rounds HyStart++ lasts in CSS before falling to CA");
-
-SYSCTL_UINT(_net_inet_tcp_cc_newreno_hystartplusplus, OID_AUTO, bblogs,
- CTLFLAG_RW,
- &hystart_bblogs, 0,
- "Do we enable HyStart++ Black Box logs to be generated if BB logging is on");
-
-
DECLARE_CC_MODULE(newreno, &newreno_cc_algo);
MODULE_VERSION(newreno, 2);
diff --git a/sys/netinet/cc/cc_newreno.h b/sys/netinet/cc/cc_newreno.h
index 42c41c7db287..791b64dfdc00 100644
--- a/sys/netinet/cc/cc_newreno.h
+++ b/sys/netinet/cc/cc_newreno.h
@@ -53,13 +53,9 @@ struct cc_newreno_opts {
#define CC_NEWRENO_BETA 1 /* Beta for normal DUP-ACK/Sack recovery */
#define CC_NEWRENO_BETA_ECN 2 /* ECN Beta for Abe */
-#define CC_NEWRENO_ENABLE_HYSTART 3 /* Enable hystart */
/* Flags values */
-#define CC_NEWRENO_HYSTART_ALLOWED 0x0001 /* Does the tcp connection allow hystart? */
#define CC_NEWRENO_HYSTART_ENABLED 0x0002 /* We can do hystart, a loss removes this flag */
#define CC_NEWRENO_HYSTART_IN_CSS 0x0004 /* If we enter hystart CSS this flag is set */
-#define CC_NEWRENO_HYSTART_CAN_SH_CWND 0x0008 /* Can hystart when going CSS -> CA slam the cwnd */
-#define CC_NEWRENO_HYSTART_CONS_SSTH 0x0010 /* Should hystart use the more conservative sstrhesh */
#define CC_NEWRENO_BETA_ECN_ENABLED 0x0020
#endif /* _CC_NEWRENO_H */
diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c
index 4ad6a12ee43b..459520a4a0bb 100644
--- a/sys/netinet/tcp_stacks/rack.c
+++ b/sys/netinet/tcp_stacks/rack.c
@@ -12858,15 +12858,11 @@ rack_init(struct tcpcb *tp)
rack_convert_rtts(tp);
tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
if (rack_do_hystart) {
- struct sockopt sopt;
- struct cc_newreno_opts opt;
-
- sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
- sopt.sopt_dir = SOPT_SET;
- opt.name = CC_NEWRENO_ENABLE_HYSTART;
- opt.val = rack_do_hystart;
- if (CC_ALGO(tp)->ctl_output != NULL)
- (void)CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
+ tp->ccv->flags |= CCF_HYSTART_ALLOWED;
+ if (rack_do_hystart > 1)
+ tp->ccv->flags |= CCF_HYSTART_CAN_SH_CWND;
+ if (rack_do_hystart > 2)
+ tp->ccv->flags |= CCF_HYSTART_CONS_SSTH;
}
if (rack_def_profile)
rack_set_profile(rack, rack_def_profile);
@@ -13515,7 +13511,6 @@ rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_ct
}
}
-
static int
rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
{
@@ -13766,7 +13761,29 @@ rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mb
(((ae->ack - high_seq) + segsiz - 1) / segsiz));
#endif
high_seq = ae->ack;
- if (SEQ_GEQ(high_seq, rack->r_ctl.roundends)) {
+ if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
+ union tcp_log_stackspecific log;
+ struct timeval tv;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.timeStamp = tcp_get_usecs(&tv);
+ log.u_bbr.flex1 = high_seq;
+ log.u_bbr.flex2 = rack->r_ctl.roundends;
+ log.u_bbr.flex3 = rack->r_ctl.current_round;
+ log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
+ log.u_bbr.flex8 = 8;
+ tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
+ 0, &log, false, NULL, NULL, 0, &tv);
+ }
+ /*
+ * The draft (v3) calls for us to use SEQ_GEQ, but that
+ * causes issues when we are just going app limited. Lets
+ * instead use SEQ_GT <or> where its equal but more data
+ * is outstanding.
+ */
+ if ((SEQ_GT(high_seq, rack->r_ctl.roundends)) ||
+ ((high_seq == rack->r_ctl.roundends) &&
+ SEQ_GT(tp->snd_max, tp->snd_una))) {
rack->r_ctl.current_round++;
rack->r_ctl.roundends = tp->snd_max;
if (CC_ALGO(tp)->newround != NULL) {
@@ -14194,7 +14211,7 @@ rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
* us_cts - is the time that LRO or hardware actually got the packet in microseconds.
*/
uint32_t cts, us_cts, ms_cts;
- uint32_t tiwin;
*** 115 LINES SKIPPED ***