Date: Mon, 30 Jun 2014 21:54:01 +0100 From: Tom Jones <jones@sdf.org> To: Adrian Chadd <adrian@freebsd.org> Cc: freebsd-net@freebsd.org Subject: Re: [PATCH] Implementation of draft-ietf-tcpm-newcwv-06 Message-ID: <20140630205359.GA2221@gmail.com> In-Reply-To: <CAJ-VmonjB5C%2BDfJkDUeyJrqzHa1ptaQPZYtcyqN1PpKeii51Fg@mail.gmail.com> References: <20140630170453.GA21404@gmail.com> <CAJ-VmonjB5C%2BDfJkDUeyJrqzHa1ptaQPZYtcyqN1PpKeii51Fg@mail.gmail.com>
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On Mon, Jun 30, 2014 at 12:29:44PM -0700, Adrian Chadd wrote: > Hi! > > Cool! Would you mind throwing it into a bugzilla ticket so it's not > lost and it can be assigned for some review? > > http://bugs.freebsd.org/submit/ Done. https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=191520 > Is there any benefit in hanging this state off of it as a pointer to > some other struct, rather than having it in the tcpcb? Is it always > going to be used? The draft recommends newcwv be used as a default, so there is a chance it will always be around. What would the impact to performance be by moving the state out into a struct? > On 30 June 2014 10:04, Tom Jones <jones@sdf.org> wrote: > > Hello, > > > > Attached is a patch which implements draft-ietf-tcpm-newcwv-06, "Updating TCP > > to support Rate-Limited Traffic". The patch is a port of the Linux > > implementation by Raffaello Secchi with influence from Aris > > Angelogiannopoulos's patch set that was sent to the list earlier this year. > > > > -- > > Tom | I don't see how we are going to build the dystopian megapoli > > @adventureloop | we were promised in 80s and early 90s cyberpunk fiction if > > adventurist.me | you guys keep complaining. > > > > Index: sys/conf/files > > =================================================================== > > --- sys/conf/files (revision 268040) > > +++ sys/conf/files (working copy) > > @@ -3380,6 +3380,7 @@ netinet/tcp_reass.c optional inet | inet6 > > netinet/tcp_sack.c optional inet | inet6 > > netinet/tcp_subr.c optional inet | inet6 > > netinet/tcp_syncache.c optional inet | inet6 > > +netinet/tcp_newcwv.c optional inet | inet6 > > netinet/tcp_timer.c optional inet | inet6 > > netinet/tcp_timewait.c optional inet | inet6 > > netinet/tcp_usrreq.c optional inet | inet6 > > Index: sys/netinet/tcp_input.c > > =================================================================== > > --- sys/netinet/tcp_input.c (revision 268040) > > +++ sys/netinet/tcp_input.c (working copy) > > @@ -105,6 +105,7 @@ __FBSDID("$FreeBSD$"); > > #include <netinet6/tcp6_var.h> > > #include <netinet/tcpip.h> > > #include <netinet/tcp_syncache.h> > > +#include <netinet/tcp_newcwv.h> > > #ifdef TCPDEBUG > > #include <netinet/tcp_debug.h> > > #endif /* TCPDEBUG */ > > @@ -174,6 +175,11 @@ SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, abc_l_var > > &VNET_NAME(tcp_abc_l_var), 2, > > "Cap the max cwnd increment during slow-start to this number of segments"); > > > > +VNET_DEFINE(int, tcp_do_newcwv) = 0; > > +SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, newcwv, CTLFLAG_RW, > > + &VNET_NAME(tcp_do_newcwv), 0, > > + "Enable draft-ietf-tcpm-newcwv-06 (New Congestion Window Validation)"); > > + > > static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, ecn, CTLFLAG_RW, 0, "TCP ECN"); > > > > VNET_DEFINE(int, tcp_do_ecn) = 0; > > @@ -309,6 +315,12 @@ cc_ack_received(struct tcpcb *tp, struct tcphdr *t > > tp->ccv->curack = th->th_ack; > > CC_ALGO(tp)->ack_received(tp->ccv, type); > > } > > + > > + /* > > + * update draft-ietf-newcwv-06 pipeack > > + */ > > + if(V_tcp_do_newcwv && !IN_FASTRECOVERY(tp->t_flags)) > > + tcp_newcwv_update_pipeack(tp); > > } > > > > static void inline > > @@ -378,6 +390,12 @@ cc_conn_init(struct tcpcb *tp) > > tp->snd_cwnd = 4 * tp->t_maxseg; > > } > > > > + /* > > + * Initialise NewCWV state > > + */ > > + tp->init_cwnd = tp->snd_cwnd; > > + tcp_newcwv_reset(tp); > > + > > if (CC_ALGO(tp)->conn_init != NULL) > > CC_ALGO(tp)->conn_init(tp->ccv); > > } > > @@ -426,6 +444,11 @@ cc_cong_signal(struct tcpcb *tp, struct tcphdr *th > > tp->t_badrxtwin = 0; > > break; > > } > > + > > + if (V_tcp_do_newcwv && > > + (type == CC_NDUPACK || type == CC_ECN) && > > + tp->pipeack <= (tp->snd_cwnd >> 1) ) > > + tcp_newcwv_enter_recovery(tp); > > > > if (CC_ALGO(tp)->cong_signal != NULL) { > > if (th != NULL) > > @@ -447,6 +470,13 @@ cc_post_recovery(struct tcpcb *tp, struct tcphdr * > > } > > /* XXXLAS: EXIT_RECOVERY ? */ > > tp->t_bytes_acked = 0; > > + > > + if(V_tcp_do_newcwv) { > > + if(tp->loss_flight_size) > > + tcp_newcwv_end_recovery(tp); > > + tcp_newcwv_reset(tp); > > + } > > + tp->loss_flight_size = 0; > > } > > > > #ifdef TCP_SIGNATURE > > Index: sys/netinet/tcp_newcwv.c > > =================================================================== > > --- sys/netinet/tcp_newcwv.c (revision 0) > > +++ sys/netinet/tcp_newcwv.c (working copy) > > @@ -0,0 +1,174 @@ > > +/* > > + * Copyright (c) 2014 Tom Jones <jones@sdf.org> > > + * All rights reserved. > > + * > > + * Redistribution and use in source and binary forms, with or without > > + * modification, are permitted provided that the following conditions > > + * are met: > > + * 1. Redistributions of source code must retain the above copyright > > + * notice, this list of conditions and the following disclaimer. > > + * 2. Redistributions in binary form must reproduce the above copyright > > + * notice, this list of conditions and the following disclaimer in the > > + * documentation and/or other materials provided with the distribution. > > + * > > + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND > > + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE > > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE > > + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE > > + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL > > + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS > > + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) > > + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT > > + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY > > + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF > > + * SUCH DAMAGE. > > + * > > + */ > > + > > +#include <sys/cdefs.h> > > + > > +#include <sys/param.h> > > +#include <sys/kernel.h> > > +#include <sys/libkern.h> > > +#include <sys/socket.h> > > +#include <sys/socketvar.h> > > + > > +#include <netinet/tcp.h> > > +#include <netinet/tcp_var.h> > > +#include <netinet/tcp_newcwv.h> > > + > > +/* > > + * An implementation of NewCWV (draft-ietf-tcpm-newcwv-06) for FreeBSD. > > + * Based on the Linux implementation by Raffaello Secchi and the an initial > > + * implementation of draft-ietf-tcpm-newcwv-00 by Aris Angelogiannopoulos. > > + */ > > + > > +#define nextbin(x) (((x)+1) & 0x03) > > +#define prevbin(x) (((x)-1) & 0x03) > > + > > +#define NCWV_UNDEF 0xFFFFFFFF > > +#define NCWV_FIVEMINS (300*hz) > > + > > +void add_element(struct tcpcb *,u_int32_t); > > +u_int32_t remove_expired_elements(struct tcpcb *); > > + > > +void > > +tcp_newcwv_update_pipeack(struct tcpcb *tp) > > +{ > > + u_int32_t tmp_pipeack; > > + tp->psp = MAX(3 * tp->t_srtt,hz); > > + > > + if (tp->snd_una >= tp->prev_snd_nxt) { > > + /* get the pipeack sample */ > > + tmp_pipeack = tp->snd_una - tp->prev_snd_una; > > + > > + tp->prev_snd_una = tp->snd_una; > > + tp->prev_snd_nxt = tp->snd_nxt; > > + > > + /* create a new element at the end of current pmp */ > > + if(ticks > tp->time_stamp[tp->head] + (tp->psp >> 2)) > > + add_element(tp,tmp_pipeack); > > + else > > + tp->psample[tp->head] = tmp_pipeack; > > + } > > + > > + tp->pipeack = remove_expired_elements(tp); > > + > > + /* check if cwnd is validated */ > > + if (tp->pipeack == NCWV_UNDEF || > > + ((tp->pipeack << 1) >= (tp->snd_cwnd * tp->t_maxseg))) { > > + tp->cwnd_valid_ts = ticks; > > + } > > +} > > + > > +void > > +add_element(struct tcpcb *tp,u_int32_t value) > > +{ > > + tp->head = nextbin(tp->head); > > + tp->psample[tp->head] = value; > > + tp->time_stamp[tp->head] = ticks; > > +} > > + > > +u_int32_t > > +remove_expired_elements(struct tcpcb *tp) > > +{ > > + uint8_t head = tp->head; > > + u_int32_t tmp = tp->psample[head]; > > + > > + while(tp->psample[head] != NCWV_UNDEF) { > > + /* remove the element if expired */ > > + if (tp->time_stamp[head] < ticks - tp->psp) { > > + tp->psample[head] = NCWV_UNDEF; > > + return tmp; > > + } > > + > > + /* search for the max pipeack */ > > + if(tp->psample[head] > tmp) > > + tmp = tp->psample[head]; > > + > > + head = prevbin(head); > > + if(head == tp->head) > > + return tmp; > > + } > > + > > + return tmp; > > +} > > + > > +/* Initialise NewCWV state */ > > +void > > +tcp_newcwv_reset(struct tcpcb *tp) > > +{ > > + tp->prev_snd_una = tp->snd_una; > > + tp->prev_snd_nxt = tp->snd_nxt; > > + tp->cwnd_valid_ts = ticks; > > + tp->loss_flight_size = 0; > > + > > + tp->head = 0; > > + tp->psample[0] = NCWV_UNDEF; > > + tp->pipeack = NCWV_UNDEF; > > +} > > + > > +/* NewCWV actions at loss detection */ > > +void > > +tcp_newcwv_enter_recovery(struct tcpcb *tp) > > +{ > > + u_int32_t pipe; > > + > > + if(tp->pipeack == NCWV_UNDEF) > > + return; > > + > > + tp->prior_retrans = tp->t_sndrexmitpack; > > + > > + /* Calculate the flight size */ > > + u_int32_t awnd = (tp->snd_nxt - tp->snd_fack) + tp->sackhint.sack_bytes_rexmit; > > + tp->loss_flight_size = awnd; > > + > > + pipe = MAX(tp->pipeack,tp->loss_flight_size); > > + tp->snd_cwnd = MAX(pipe >> 1,1); > > +} > > + > > +/* NewCWV actions at the end of recovery */ > > +void > > +tcp_newcwv_end_recovery(struct tcpcb *tp) > > +{ > > + u_int32_t retrans,pipe; > > + > > + retrans = (tp->t_sndrexmitpack - tp->prior_retrans) * tp->t_maxseg; > > + pipe = MAX(tp->pipeack,tp->loss_flight_size) - retrans; > > + > > + /* Ensure that snd_ssthresh is non 0 */ > > + tp->snd_ssthresh = MAX(pipe >> 1,1); > > + tp->snd_cwnd = tp->snd_ssthresh; > > +} > > + > > +void > > +tcp_newcwv_datalim_closedown(struct tcpcb *tp) > > +{ > > + while ((ticks - tp->cwnd_valid_ts) > NCWV_FIVEMINS && > > + tp->snd_cwnd > tp->init_cwnd) { > > + > > + tp->cwnd_valid_ts += NCWV_FIVEMINS; > > + tp->snd_ssthresh = MAX( (3 * tp->snd_cwnd ) >> 2,tp->snd_ssthresh); > > + tp->snd_cwnd = MAX(tp->snd_cwnd >> 1, tp->init_cwnd); > > + } > > +} > > > > Property changes on: sys/netinet/tcp_newcwv.c > > ___________________________________________________________________ > > Added: svn:mime-type > > ## -0,0 +1 ## > > +text/plain > > \ No newline at end of property > > Added: svn:keywords > > ## -0,0 +1 ## > > +FreeBSD=%H > > \ No newline at end of property > > Added: svn:eol-style > > ## -0,0 +1 ## > > +native > > \ No newline at end of property > > Index: sys/netinet/tcp_newcwv.h > > =================================================================== > > --- sys/netinet/tcp_newcwv.h (revision 0) > > +++ sys/netinet/tcp_newcwv.h (working copy) > > @@ -0,0 +1,39 @@ > > +/* > > + * Copyright (c) 2014 Tom Jones <jones@sdf.org> > > + * All rights reserved. > > + * > > + * Redistribution and use in source and binary forms, with or without > > + * modification, are permitted provided that the following conditions > > + * are met: > > + * 1. Redistributions of source code must retain the above copyright > > + * notice, this list of conditions and the following disclaimer. > > + * 2. Redistributions in binary form must reproduce the above copyright > > + * notice, this list of conditions and the following disclaimer in the > > + * documentation and/or other materials provided with the distribution. > > + * > > + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND > > + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE > > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE > > + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE > > + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL > > + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS > > + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) > > + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT > > + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY > > + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF > > + * SUCH DAMAGE. > > + * > > + */ > > + > > +#ifndef _NETINET_TCP_NEWCWV_H_ > > +#define _NETINET_TCP_NEWCWV_H_ > > + > > +#include <netinet/tcp_var.h> > > + > > +void tcp_newcwv_update_pipeack(struct tcpcb *); > > +void tcp_newcwv_reset(struct tcpcb *); > > +void tcp_newcwv_enter_recovery(struct tcpcb *); > > +void tcp_newcwv_end_recovery(struct tcpcb *); > > +void tcp_newcwv_datalim_closedown(struct tcpcb *); > > + > > +#endif /* _NETINET_TCP_NEWCWV_H_ */ > > > > Property changes on: sys/netinet/tcp_newcwv.h > > ___________________________________________________________________ > > Added: svn:keywords > > ## -0,0 +1 ## > > +FreeBSD=%H > > \ No newline at end of property > > Added: svn:eol-style > > ## -0,0 +1 ## > > +native > > \ No newline at end of property > > Added: svn:mime-type > > ## -0,0 +1 ## > > +text/plain > > \ No newline at end of property > > Index: sys/netinet/tcp_output.c > > =================================================================== > > --- sys/netinet/tcp_output.c (revision 268040) > > +++ sys/netinet/tcp_output.c (working copy) > > @@ -74,6 +74,7 @@ __FBSDID("$FreeBSD$"); > > #include <netinet/tcp_timer.h> > > #include <netinet/tcp_var.h> > > #include <netinet/tcpip.h> > > +#include <netinet/tcp_newcwv.h> > > #ifdef TCPDEBUG > > #include <netinet/tcp_debug.h> > > #endif > > @@ -691,6 +692,10 @@ send: > > #endif > > hdrlen = sizeof (struct tcpiphdr); > > > > + /* Trigger the newcwv timer */ > > + if(V_tcp_do_newcwv) > > + tcp_newcwv_datalim_closedown(tp); > > + > > /* > > * Compute options for segment. > > * We only have to care about SYN and established connection > > Index: sys/netinet/tcp_subr.c > > =================================================================== > > --- sys/netinet/tcp_subr.c (revision 268040) > > +++ sys/netinet/tcp_subr.c (working copy) > > @@ -800,6 +800,7 @@ tcp_newtcpcb(struct inpcb *inp) > > tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); > > if (V_tcp_do_sack) > > tp->t_flags |= TF_SACK_PERMIT; > > + > > TAILQ_INIT(&tp->snd_holes); > > tp->t_inpcb = inp; /* XXX */ > > /* > > Index: sys/netinet/tcp_var.h > > =================================================================== > > --- sys/netinet/tcp_var.h (revision 268040) > > +++ sys/netinet/tcp_var.h (working copy) > > @@ -172,6 +172,20 @@ struct tcpcb { > > int t_sndzerowin; /* zero-window updates sent */ > > u_int t_badrxtwin; /* window for retransmit recovery */ > > u_char snd_limited; /* segments limited transmitted */ > > +/* NewCWV releated state */ > > + u_int32_t pipeack; > > + u_int32_t psp; /* pipeack sampling period */ > > + > > + u_int32_t head; > > + u_int32_t psample[4]; /* pipe ack samples */ > > + u_int32_t time_stamp[4]; /* time stamp samples */ > > + u_int32_t prev_snd_una; /* previous snd_una in this sampe */ > > + u_int32_t prev_snd_nxt; /* previous snd_nxt in this sampe */ > > + > > + u_int32_t loss_flight_size; /* flightsize at loss detection */ > > + u_int32_t prior_retrans; /* Retransmission before going into FR */ > > + u_int32_t cwnd_valid_ts; /*last time cwnd was found valid */ > > + u_int32_t init_cwnd; /* The inital cwnd */ > > /* SACK related state */ > > int snd_numholes; /* number of holes seen by sender */ > > TAILQ_HEAD(sackhole_head, sackhole) snd_holes; > > @@ -605,6 +619,7 @@ VNET_DECLARE(int, tcp_recvspace); > > VNET_DECLARE(int, path_mtu_discovery); > > VNET_DECLARE(int, tcp_do_rfc3465); > > VNET_DECLARE(int, tcp_abc_l_var); > > +VNET_DECLARE(int, tcp_do_newcwv); > > #define V_tcb VNET(tcb) > > #define V_tcbinfo VNET(tcbinfo) > > #define V_tcp_mssdflt VNET(tcp_mssdflt) > > @@ -617,6 +632,7 @@ VNET_DECLARE(int, tcp_abc_l_var); > > #define V_path_mtu_discovery VNET(path_mtu_discovery) > > #define V_tcp_do_rfc3465 VNET(tcp_do_rfc3465) > > #define V_tcp_abc_l_var VNET(tcp_abc_l_var) > > +#define V_tcp_do_newcwv VNET(tcp_do_newcwv) > > > > VNET_DECLARE(int, tcp_do_sack); /* SACK enabled/disabled */ > > VNET_DECLARE(int, tcp_sc_rst_sock_fail); /* RST on sock alloc failure */ > > > > _______________________________________________ > > freebsd-net@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-net > > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" -- Tom @adventureloop adventurist.me #pragma summon cthulhu :wq
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