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Diffstat (limited to 'sys/netinet/cc/cc_newreno.c')
-rw-r--r--sys/netinet/cc/cc_newreno.c335
1 files changed, 305 insertions, 30 deletions
diff --git a/sys/netinet/cc/cc_newreno.c b/sys/netinet/cc/cc_newreno.c
index 8f939ad70695..23d2b273f6aa 100644
--- a/sys/netinet/cc/cc_newreno.c
+++ b/sys/netinet/cc/cc_newreno.c
@@ -63,15 +63,21 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/socket.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <net/vnet.h>
+#include <netinet/in.h>
+#include <netinet/in_pcb.h>
#include <netinet/tcp.h>
#include <netinet/tcp_seq.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_module.h>
#include <netinet/cc/cc_newreno.h>
@@ -85,6 +91,9 @@ static void newreno_after_idle(struct cc_var *ccv);
static void newreno_cong_signal(struct cc_var *ccv, uint32_t type);
static void newreno_post_recovery(struct cc_var *ccv);
static int newreno_ctl_output(struct cc_var *ccv, struct sockopt *sopt, void *buf);
+static void newreno_newround(struct cc_var *ccv, uint32_t round_cnt);
+static void newreno_rttsample(struct cc_var *ccv, uint32_t usec_rtt, uint32_t rxtcnt, uint32_t fas);
+static int newreno_cb_init(struct cc_var *ccv);
VNET_DEFINE(uint32_t, newreno_beta) = 50;
VNET_DEFINE(uint32_t, newreno_beta_ecn) = 80;
@@ -99,23 +108,95 @@ struct cc_algo newreno_cc_algo = {
.cong_signal = newreno_cong_signal,
.post_recovery = newreno_post_recovery,
.ctl_output = newreno_ctl_output,
+ .newround = newreno_newround,
+ .rttsample = newreno_rttsample,
+ .cb_init = newreno_cb_init,
};
-static inline struct newreno *
-newreno_malloc(struct cc_var *ccv)
-{
- struct newreno *nreno;
+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;
- nreno = malloc(sizeof(struct newreno), M_NEWRENO, M_NOWAIT);
- if (nreno != NULL) {
- /* NB: nreno is not zeroed, so initialise all fields. */
- nreno->beta = V_newreno_beta;
- nreno->beta_ecn = V_newreno_beta_ecn;
- nreno->newreno_flags = 0;
- ccv->cc_data = nreno;
+static void
+newreno_log_hystart_event(struct cc_var *ccv, struct newreno *nreno, 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
+ */
+ 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 = nreno->css_current_round_minrtt;
+ log.u_bbr.flex3 = nreno->css_lastround_minrtt;
+ log.u_bbr.flex4 = nreno->css_rttsample_count;
+ log.u_bbr.flex5 = nreno->css_entered_at_round;
+ log.u_bbr.flex6 = nreno->css_baseline_minrtt;
+ /* We only need bottom 16 bits of flags */
+ log.u_bbr.flex7 = nreno->newreno_flags & 0x0000ffff;
+ log.u_bbr.flex8 = mod;
+ log.u_bbr.epoch = nreno->css_current_round;
+ log.u_bbr.timeStamp = tcp_get_usecs(&tv);
+ 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;
+ 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 int
+newreno_cb_init(struct cc_var *ccv)
+{
+ struct newreno *nreno;
- return (nreno);
+ ccv->cc_data = NULL;
+ ccv->cc_data = malloc(sizeof(struct newreno), M_NEWRENO, M_NOWAIT);
+ if (ccv->cc_data == NULL)
+ return (ENOMEM);
+ nreno = (struct newreno *)ccv->cc_data;
+ /* NB: nreno is not zeroed, so initialise all fields. */
+ nreno->beta = V_newreno_beta;
+ nreno->beta_ecn = V_newreno_beta_ecn;
+ /*
+ * We set the enabled flag so that if
+ * the socket option gets strobed and
+ * we have not hit a loss
+ */
+ nreno->newreno_flags = CC_NEWRENO_HYSTART_ENABLED;
+ /* At init set both to infinity */
+ nreno->css_lastround_minrtt = 0xffffffff;
+ nreno->css_current_round_minrtt = 0xffffffff;
+ nreno->css_current_round = 0;
+ nreno->css_baseline_minrtt = 0xffffffff;
+ nreno->css_rttsample_count = 0;
+ nreno->css_entered_at_round = 0;
+ nreno->css_fas_at_css_entry = 0;
+ nreno->css_lowrtt_fas = 0;
+ nreno->css_last_fas = 0;
+ return (0);
}
static void
@@ -127,6 +208,9 @@ newreno_cb_destroy(struct cc_var *ccv)
static void
newreno_ack_received(struct cc_var *ccv, uint16_t type)
{
+ struct newreno *nreno;
+
+ nreno = (struct newreno *)ccv->cc_data;
if (type == CC_ACK && !IN_RECOVERY(CCV(ccv, t_flags)) &&
(ccv->flags & CCF_CWND_LIMITED)) {
u_int cw = CCV(ccv, snd_cwnd);
@@ -160,6 +244,16 @@ newreno_ack_received(struct cc_var *ccv, uint16_t type)
* avoid capping cwnd.
*/
if (cw > CCV(ccv, snd_ssthresh)) {
+ if (nreno->newreno_flags & CC_NEWRENO_HYSTART_IN_CSS) {
+ /*
+ * We have slipped into CA with
+ * CSS active. Deactivate all.
+ */
+ /* Turn off the CSS flag */
+ 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;
+ }
if (V_tcp_do_rfc3465) {
if (ccv->flags & CCF_ABC_SENTAWND)
ccv->flags &= ~CCF_ABC_SENTAWND;
@@ -184,12 +278,48 @@ 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) &&
+ (nreno->newreno_flags & CC_NEWRENO_HYSTART_ENABLED) &&
+ ((nreno->newreno_flags & CC_NEWRENO_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 ((nreno->css_rttsample_count >= hystart_n_rttsamples) &&
+ (CCV(ccv, snd_cwnd) >
+ (hystart_lowcwnd * tcp_fixed_maxseg(ccv->ccvc.tcp)))) {
+ uint32_t rtt_thresh;
+
+ /* Clamp (minrtt_thresh, lastround/8, maxrtt_thresh) */
+ rtt_thresh = (nreno->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;
+ newreno_log_hystart_event(ccv, nreno, 1, rtt_thresh);
+ if (nreno->css_current_round_minrtt >= (nreno->css_lastround_minrtt + rtt_thresh)) {
+ /* Enter CSS */
+ nreno->newreno_flags |= CC_NEWRENO_HYSTART_IN_CSS;
+ nreno->css_fas_at_css_entry = nreno->css_lowrtt_fas;
+ 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);
+ }
+ }
+ }
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 (nreno->newreno_flags & CC_NEWRENO_HYSTART_IN_CSS) {
+ incr /= hystart_css_growth_div;
+ newreno_log_hystart_event(ccv, nreno, 3, incr);
+ }
}
/* ABC is on by default, so incr equals 0 frequently. */
if (incr > 0)
@@ -201,8 +331,10 @@ newreno_ack_received(struct cc_var *ccv, uint16_t type)
static void
newreno_after_idle(struct cc_var *ccv)
{
+ struct newreno *nreno;
uint32_t rw;
+ nreno = (struct newreno *)ccv->cc_data;
/*
* If we've been idle for more than one retransmit timeout the old
* congestion window is no longer current and we have to reduce it to
@@ -226,6 +358,16 @@ newreno_after_idle(struct cc_var *ccv)
CCV(ccv, snd_cwnd)-(CCV(ccv, snd_cwnd)>>2));
CCV(ccv, snd_cwnd) = min(rw, CCV(ccv, snd_cwnd));
+ 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;
+ }
+ }
}
/*
@@ -240,15 +382,9 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
cwin = CCV(ccv, snd_cwnd);
mss = tcp_fixed_maxseg(ccv->ccvc.tcp);
- /*
- * Other TCP congestion controls use newreno_cong_signal(), but
- * with their own private cc_data. Make sure the cc_data is used
- * correctly.
- */
- nreno = (CC_ALGO(ccv->ccvc.tcp) == &newreno_cc_algo) ? ccv->cc_data : NULL;
- beta = (nreno == NULL) ? V_newreno_beta : nreno->beta;
- beta_ecn = (nreno == NULL) ? V_newreno_beta_ecn : nreno->beta_ecn;
-
+ nreno = (struct newreno *) ccv->cc_data;
+ beta = nreno->beta;
+ beta_ecn = nreno->beta_ecn;
/*
* Note that we only change the backoff for ECN if the
* global sysctl V_cc_do_abe is set <or> the stack itself
@@ -257,7 +393,7 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
*/
if ((type == CC_ECN) &&
(V_cc_do_abe ||
- ((nreno != NULL) && (nreno->newreno_flags & CC_NEWRENO_BETA_ECN))))
+ ((nreno != NULL) && (nreno->newreno_flags & CC_NEWRENO_BETA_ECN_ENABLED))))
factor = beta_ecn;
else
factor = beta;
@@ -271,6 +407,11 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
switch (type) {
case CC_NDUPACK:
+ if (nreno->newreno_flags & CC_NEWRENO_HYSTART_ENABLED) {
+ /* 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;
+ }
if (!IN_FASTRECOVERY(CCV(ccv, t_flags))) {
if (IN_CONGRECOVERY(CCV(ccv, t_flags) &&
V_cc_do_abe && V_cc_abe_frlossreduce)) {
@@ -284,6 +425,11 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
}
break;
case CC_ECN:
+ if (nreno->newreno_flags & CC_NEWRENO_HYSTART_ENABLED) {
+ /* 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;
+ }
if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) {
CCV(ccv, snd_ssthresh) = cwin;
CCV(ccv, snd_cwnd) = cwin;
@@ -346,17 +492,10 @@ newreno_ctl_output(struct cc_var *ccv, struct sockopt *sopt, void *buf)
if (CC_ALGO(ccv->ccvc.tcp) != &newreno_cc_algo)
return (ENOPROTOOPT);
- nreno = ccv->cc_data;
+ nreno = (struct newreno *)ccv->cc_data;
opt = buf;
-
switch (sopt->sopt_dir) {
case SOPT_SET:
- /* We cannot set without cc_data memory. */
- if (nreno == NULL) {
- nreno = newreno_malloc(ccv);
- if (nreno == NULL)
- return (ENOMEM);
- }
switch (opt->name) {
case CC_NEWRENO_BETA:
nreno->beta = opt->val;
@@ -365,6 +504,19 @@ newreno_ctl_output(struct cc_var *ccv, struct sockopt *sopt, void *buf)
if ((!V_cc_do_abe) && ((nreno->newreno_flags & CC_NEWRENO_BETA_ECN) == 0))
return (EACCES);
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);
@@ -380,6 +532,17 @@ 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);
}
@@ -411,6 +574,78 @@ newreno_beta_handler(SYSCTL_HANDLER_ARGS)
return (error);
}
+static void
+newreno_newround(struct cc_var *ccv, uint32_t round_cnt)
+{
+ struct newreno *nreno;
+
+ nreno = (struct newreno *)ccv->cc_data;
+ /* We have entered a new round */
+ nreno->css_lastround_minrtt = nreno->css_current_round_minrtt;
+ nreno->css_current_round_minrtt = 0xffffffff;
+ nreno->css_rttsample_count = 0;
+ nreno->css_current_round = 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) {
+ /*
+ * 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) {
+ CCV(ccv, snd_ssthresh) = ((nreno->css_lowrtt_fas + nreno->css_fas_at_css_entry) / 2);
+ } else {
+ CCV(ccv, snd_ssthresh) = nreno->css_lowrtt_fas;
+ }
+ CCV(ccv, snd_cwnd) = nreno->css_fas_at_css_entry;
+ nreno->css_entered_at_round = round_cnt;
+ } else {
+ CCV(ccv, snd_ssthresh) = CCV(ccv, snd_cwnd);
+ /* Turn off the CSS flag */
+ 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, 6, CCV(ccv, snd_ssthresh));
+ }
+ newreno_log_hystart_event(ccv, nreno, 4, round_cnt);
+}
+
+static void
+newreno_rttsample(struct cc_var *ccv, uint32_t usec_rtt, uint32_t rxtcnt, uint32_t fas)
+{
+ struct newreno *nreno;
+
+ nreno = (struct newreno *)ccv->cc_data;
+ if (rxtcnt > 1) {
+ /*
+ * Only look at RTT's that are non-ambiguous.
+ */
+ return;
+ }
+ nreno->css_rttsample_count++;
+ nreno->css_last_fas = fas;
+ if (nreno->css_current_round_minrtt > usec_rtt) {
+ 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)) {
+ /*
+ * We were in CSS and the RTT is now less, we
+ * entered CSS erroneously.
+ */
+ nreno->newreno_flags &= ~CC_NEWRENO_HYSTART_IN_CSS;
+ 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);
+}
+
SYSCTL_DECL(_net_inet_tcp_cc_newreno);
SYSCTL_NODE(_net_inet_tcp_cc, OID_AUTO, newreno,
CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
@@ -426,5 +661,45 @@ 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, 1);
generated by cgit v1.2.3 (git 2.25.1) at 2023-06-08 08:52:50 +0000