svn commit: r367752 - in stable/12/sys/netinet: . cc

[Richard Scheffenegger]

Author: rscheff
Date: Tue Nov 17 08:03:49 2020
New Revision: 367752
URL: https://svnweb.freebsd.org/changeset/base/367752

Log:
  MFC r367007: tcp: move cwnd and ssthresh updates into cc modules
  
  This will pave the way of setting ssthresh differently in TCP CUBIC, according
  to RFC8312 section 4.7.
  
  Use dynamic tcp_maxseg() adjusting for tcp options instead of static t_maxseg.
  
  Submitted by:	chengc_netapp.com
  Reviewed by:	rrs, tuexen, rscheff
  Sponsored by:	NetApp, Inc.
  Differential Revision:	https://reviews.freebsd.org/D26807

Modified:
  stable/12/sys/netinet/cc/cc_cubic.c
  stable/12/sys/netinet/cc/cc_dctcp.c
  stable/12/sys/netinet/cc/cc_htcp.c
  stable/12/sys/netinet/cc/cc_newreno.c
  stable/12/sys/netinet/tcp_input.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/netinet/cc/cc_cubic.c
==============================================================================
--- stable/12/sys/netinet/cc/cc_cubic.c	Tue Nov 17 06:04:16 2020	(r367751)
+++ stable/12/sys/netinet/cc/cc_cubic.c	Tue Nov 17 08:03:49 2020	(r367752)
@@ -265,8 +265,10 @@ static void
 cubic_cong_signal(struct cc_var *ccv, uint32_t type)
 {
 	struct cubic *cubic_data;
+	u_int mss;
 
 	cubic_data = ccv->cc_data;
+	mss = tcp_maxseg(ccv->ccvc.tcp);
 
 	switch (type) {
 	case CC_NDUPACK:
@@ -293,6 +295,10 @@ cubic_cong_signal(struct cc_var *ccv, uint32_t type)
 		break;
 
 	case CC_RTO:
+		CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+						 CCV(ccv, snd_cwnd)) / 2 / mss,
+					     2) * mss;
+		CCV(ccv, snd_cwnd) = mss;
 		/*
 		 * Grab the current time and record it so we know when the
 		 * most recent congestion event was. Only record it when the

Modified: stable/12/sys/netinet/cc/cc_dctcp.c
==============================================================================
--- stable/12/sys/netinet/cc/cc_dctcp.c	Tue Nov 17 06:04:16 2020	(r367751)
+++ stable/12/sys/netinet/cc/cc_dctcp.c	Tue Nov 17 08:03:49 2020	(r367752)
@@ -235,7 +235,7 @@ dctcp_cong_signal(struct cc_var *ccv, uint32_t type)
 	if (CCV(ccv, t_flags) & TF_ECN_PERMIT) {
 		dctcp_data = ccv->cc_data;
 		cwin = CCV(ccv, snd_cwnd);
-		mss = CCV(ccv, t_maxseg);
+		mss = tcp_maxseg(ccv->ccvc.tcp);
 
 		switch (type) {
 		case CC_NDUPACK:
@@ -282,6 +282,10 @@ dctcp_cong_signal(struct cc_var *ccv, uint32_t type)
 			dctcp_data->ece_curr = 1;
 			break;
 		case CC_RTO:
+			CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+							 CCV(ccv, snd_cwnd)) / 2 / mss,
+						     2) * mss;
+			CCV(ccv, snd_cwnd) = mss;
 			dctcp_update_alpha(ccv);
 			dctcp_data->save_sndnxt += CCV(ccv, t_maxseg);
 			dctcp_data->num_cong_events++;

Modified: stable/12/sys/netinet/cc/cc_htcp.c
==============================================================================
--- stable/12/sys/netinet/cc/cc_htcp.c	Tue Nov 17 06:04:16 2020	(r367751)
+++ stable/12/sys/netinet/cc/cc_htcp.c	Tue Nov 17 08:03:49 2020	(r367752)
@@ -271,8 +271,10 @@ static void
 htcp_cong_signal(struct cc_var *ccv, uint32_t type)
 {
 	struct htcp *htcp_data;
+	u_int mss;
 
 	htcp_data = ccv->cc_data;
+	mss = tcp_maxseg(ccv->ccvc.tcp);
 
 	switch (type) {
 	case CC_NDUPACK:
@@ -311,6 +313,10 @@ htcp_cong_signal(struct cc_var *ccv, uint32_t type)
 		break;
 
 	case CC_RTO:
+		CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+						 CCV(ccv, snd_cwnd)) / 2 / mss,
+					     2) * mss;
+		CCV(ccv, snd_cwnd) = mss;
 		/*
 		 * Grab the current time and record it so we know when the
 		 * most recent congestion event was. Only record it when the

Modified: stable/12/sys/netinet/cc/cc_newreno.c
==============================================================================
--- stable/12/sys/netinet/cc/cc_newreno.c	Tue Nov 17 06:04:16 2020	(r367751)
+++ stable/12/sys/netinet/cc/cc_newreno.c	Tue Nov 17 08:03:49 2020	(r367752)
@@ -241,7 +241,7 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
 	u_int mss;
 
 	cwin = CCV(ccv, snd_cwnd);
-	mss = CCV(ccv, t_maxseg);
+	mss = tcp_maxseg(ccv->ccvc.tcp);
 	nreno = ccv->cc_data;
 	beta = (nreno == NULL) ? V_newreno_beta : nreno->beta;
 	beta_ecn = (nreno == NULL) ? V_newreno_beta_ecn : nreno->beta_ecn;
@@ -278,6 +278,12 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
 			CCV(ccv, snd_cwnd) = cwin;
 			ENTER_CONGRECOVERY(CCV(ccv, t_flags));
 		}
+		break;
+	case CC_RTO:
+		CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+						 CCV(ccv, snd_cwnd)) / 2 / mss,
+					     2) * mss;
+		CCV(ccv, snd_cwnd) = mss;
 		break;
 	}
 }

Modified: stable/12/sys/netinet/tcp_input.c
==============================================================================
--- stable/12/sys/netinet/tcp_input.c	Tue Nov 17 06:04:16 2020	(r367751)
+++ stable/12/sys/netinet/tcp_input.c	Tue Nov 17 08:03:49 2020	(r367752)
@@ -403,8 +403,6 @@ cc_conn_init(struct tcpcb *tp)
 void inline
 cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type)
 {
-	u_int maxseg;
-
 	INP_WLOCK_ASSERT(tp->t_inpcb);
 
 	switch(type) {
@@ -430,13 +428,9 @@ cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, ui
 		}
 		break;
 	case CC_RTO:
-		maxseg = tcp_maxseg(tp);
 		tp->t_dupacks = 0;
 		tp->t_bytes_acked = 0;
 		EXIT_RECOVERY(tp->t_flags);
-		tp->snd_ssthresh = max(2, min(tp->snd_wnd, tp->snd_cwnd) / 2 /
-		    maxseg) * maxseg;
-		tp->snd_cwnd = maxseg;
 		if (tp->t_flags & TF_ECN_PERMIT)
 			tp->t_flags |= TF_ECN_SND_CWR;
 		break;