Date: Thu, 30 Nov 2023 20:40:42 GMT From: Richard Scheffenegger <rscheff@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: f42518ff1250 - main - tcp: for LRD move sysctl from tcp.do_lrd tp tcp.sack.lrd, remove sockopt Message-ID: <202311302040.3AUKegfx065904@gitrepo.freebsd.org>
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The branch main has been updated by rscheff: URL: https://cgit.FreeBSD.org/src/commit/?id=f42518ff1250fcc76a0a1eed9f411edbbb172541 commit f42518ff1250fcc76a0a1eed9f411edbbb172541 Author: Richard Scheffenegger <rscheff@FreeBSD.org> AuthorDate: 2023-11-30 20:10:14 +0000 Commit: Richard Scheffenegger <rscheff@FreeBSD.org> CommitDate: 2023-11-30 20:11:45 +0000 tcp: for LRD move sysctl from tcp.do_lrd tp tcp.sack.lrd, remove sockopt Moving lrd sysctl to the tcp.sack branch, since LRD only works with SACK. Remove the sockopt to programmatically control LRD per session. Reviewed By: #transport, tuexen, rrs Sponsored by: NetApp, Inc. Differential Revision: https://reviews.freebsd.org/D42851 --- share/man/man4/tcp.4 | 14 +++++++------- sys/netinet/tcp.h | 1 - sys/netinet/tcp_input.c | 5 ----- sys/netinet/tcp_sack.c | 5 +++++ sys/netinet/tcp_usrreq.c | 9 --------- 5 files changed, 12 insertions(+), 22 deletions(-) diff --git a/share/man/man4/tcp.4 b/share/man/man4/tcp.4 index 317ee818f3a4..4ebdbac3a3ca 100644 --- a/share/man/man4/tcp.4 +++ b/share/man/man4/tcp.4 @@ -464,13 +464,6 @@ See Maximum amount of time, in milliseconds, before a delayed ACK is sent. .It Va delayed_ack Delay ACK to try and piggyback it onto a data packet or another ACK. -.It Va do_lrd -Enable Lost Retransmission Detection for SACK-enabled sessions, enabled by -default. -Under severe congestion, a retransmission can be lost which then leads to a -mandatory Retransmission Timeout (RTO), followed by slow-start. -LRD will try to resend the repeatedly lost packet, preventing the time-consuming -RTO and performance reducing slow-start. .It Va do_prr Perform SACK loss recovery using the Proportional Rate Reduction (PRR) algorithm described in RFC6937. @@ -901,6 +894,13 @@ Global number of TCP SACK holes currently allocated. .It Va sack.globalmaxholes Maximum number of SACK holes per system, across all connections. Defaults to 65536. +.It Va sack.lrd +Enable Lost Retransmission Detection for SACK-enabled sessions, enabled by +default. +Under severe congestion, a retransmission can be lost which then leads to a +mandatory Retransmission Timeout (RTO), followed by slow-start. +LRD will try to resend the repeatedly lost packet, preventing the time-consuming +RTO and performance reducing slow-start or purge of the SACK scoreboard. .It Va sack.maxholes Maximum number of SACK holes per connection. Defaults to 128. diff --git a/sys/netinet/tcp.h b/sys/netinet/tcp.h index 70fab2c6a2d2..44f8a67a1e64 100644 --- a/sys/netinet/tcp.h +++ b/sys/netinet/tcp.h @@ -200,7 +200,6 @@ struct tcphdr { #define TCP_PROC_ACCOUNTING 76 /* Do accounting on tcp cpu usage and counts */ #define TCP_USE_CMP_ACKS 77 /* The transport can handle the Compressed mbuf acks */ #define TCP_PERF_INFO 78 /* retrieve accounting counters */ -#define TCP_LRD 79 /* toggle Lost Retransmission Detection for A/B testing */ #define TCP_KEEPINIT 128 /* N, time to establish connection */ #define TCP_KEEPIDLE 256 /* L,N,X start keeplives after this period */ #define TCP_KEEPINTVL 512 /* L,N interval between keepalives */ diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index a75dbd1547b0..b26ae92a767e 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -162,11 +162,6 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_prr, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_do_prr), 1, "Enable Proportional Rate Reduction per RFC 6937"); -VNET_DEFINE(int, tcp_do_lrd) = 1; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_lrd, CTLFLAG_VNET | CTLFLAG_RW, - &VNET_NAME(tcp_do_lrd), 1, - "Perform Lost Retransmission Detection"); - VNET_DEFINE(int, tcp_do_newcwv) = 0; SYSCTL_INT(_net_inet_tcp, OID_AUTO, newcwv, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_do_newcwv), 0, diff --git a/sys/netinet/tcp_sack.c b/sys/netinet/tcp_sack.c index 2d2be7ff922f..e8ed3c52fd67 100644 --- a/sys/netinet/tcp_sack.c +++ b/sys/netinet/tcp_sack.c @@ -132,6 +132,11 @@ SYSCTL_INT(_net_inet_tcp_sack, OID_AUTO, revised, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_do_newsack), 0, "Use revised SACK loss recovery per RFC 6675"); +VNET_DEFINE(int, tcp_do_lrd) = 1; +SYSCTL_INT(_net_inet_tcp_sack, OID_AUTO, lrd, CTLFLAG_VNET | CTLFLAG_RW, + &VNET_NAME(tcp_do_lrd), 1, + "Perform Lost Retransmission Detection"); + VNET_DEFINE(int, tcp_sack_maxholes) = 128; SYSCTL_INT(_net_inet_tcp_sack, OID_AUTO, maxholes, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_sack_maxholes), 0, diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c index 14e0b814dec9..93fdedc03c7b 100644 --- a/sys/netinet/tcp_usrreq.c +++ b/sys/netinet/tcp_usrreq.c @@ -2118,7 +2118,6 @@ tcp_default_ctloutput(struct tcpcb *tp, struct sockopt *sopt) case TCP_NODELAY: case TCP_NOOPT: - case TCP_LRD: INP_WUNLOCK(inp); error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); @@ -2133,9 +2132,6 @@ tcp_default_ctloutput(struct tcpcb *tp, struct sockopt *sopt) case TCP_NOOPT: opt = TF_NOOPT; break; - case TCP_LRD: - opt = TF_LRD; - break; default: opt = 0; /* dead code to fool gcc */ break; @@ -2657,11 +2653,6 @@ unhold: sizeof(optval)); break; #endif - case TCP_LRD: - optval = tp->t_flags & TF_LRD; - INP_WUNLOCK(inp); - error = sooptcopyout(sopt, &optval, sizeof optval); - break; default: INP_WUNLOCK(inp); error = ENOPROTOOPT;
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