Author: lstewart Date: Thu Aug 25 13:33:32 2016 New Revision: 304803 URL: https://svnweb.freebsd.org/changeset/base/304803
Log: Pass the number of segments coalesced by LRO up the stack by repurposing the tso_segsz pkthdr field during RX processing, and use the information in TCP for more correct accounting and as a congestion control input. This is only a start, and an audit of other uses for the data is left as future work. Reviewed by: gallatin, rrs Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D7564 Modified: head/sys/netinet/cc/cc.h head/sys/netinet/cc/cc_newreno.c head/sys/netinet/tcp_input.c head/sys/netinet/tcp_lro.c head/sys/netinet/tcp_var.h head/sys/sys/mbuf.h Modified: head/sys/netinet/cc/cc.h ============================================================================== --- head/sys/netinet/cc/cc.h Thu Aug 25 13:24:11 2016 (r304802) +++ head/sys/netinet/cc/cc.h Thu Aug 25 13:33:32 2016 (r304803) @@ -86,6 +86,7 @@ struct cc_var { struct tcpcb *tcp; struct sctp_nets *sctp; } ccvc; + uint16_t nsegs; /* # segments coalesced into current chain. */ }; /* cc_var flags. */ Modified: head/sys/netinet/cc/cc_newreno.c ============================================================================== --- head/sys/netinet/cc/cc_newreno.c Thu Aug 25 13:24:11 2016 (r304802) +++ head/sys/netinet/cc/cc_newreno.c Thu Aug 25 13:33:32 2016 (r304803) @@ -137,7 +137,8 @@ newreno_ack_received(struct cc_var *ccv, */ if (CCV(ccv, snd_nxt) == CCV(ccv, snd_max)) incr = min(ccv->bytes_this_ack, - V_tcp_abc_l_var * CCV(ccv, t_maxseg)); + ccv->nsegs * V_tcp_abc_l_var * + CCV(ccv, t_maxseg)); else incr = min(ccv->bytes_this_ack, CCV(ccv, t_maxseg)); } Modified: head/sys/netinet/tcp_input.c ============================================================================== --- head/sys/netinet/tcp_input.c Thu Aug 25 13:24:11 2016 (r304802) +++ head/sys/netinet/tcp_input.c Thu Aug 25 13:33:32 2016 (r304803) @@ -300,10 +300,12 @@ hhook_run_tcp_est_in(struct tcpcb *tp, s * CC wrapper hook functions */ void -cc_ack_received(struct tcpcb *tp, struct tcphdr *th, uint16_t type) +cc_ack_received(struct tcpcb *tp, struct tcphdr *th, uint16_t nsegs, + uint16_t type) { INP_WLOCK_ASSERT(tp->t_inpcb); + tp->ccv->nsegs = nsegs; tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th); if (tp->snd_cwnd <= tp->snd_wnd) tp->ccv->flags |= CCF_CWND_LIMITED; @@ -313,7 +315,7 @@ cc_ack_received(struct tcpcb *tp, struct if (type == CC_ACK) { if (tp->snd_cwnd > tp->snd_ssthresh) { tp->t_bytes_acked += min(tp->ccv->bytes_this_ack, - V_tcp_abc_l_var * tcp_maxseg(tp)); + nsegs * V_tcp_abc_l_var * tcp_maxseg(tp)); if (tp->t_bytes_acked >= tp->snd_cwnd) { tp->t_bytes_acked -= tp->snd_cwnd; tp->ccv->flags |= CCF_ABC_SENTAWND; @@ -1502,6 +1504,7 @@ tcp_do_segment(struct mbuf *m, struct tc int thflags, acked, ourfinisacked, needoutput = 0, sack_changed; int rstreason, todrop, win; u_long tiwin; + uint16_t nsegs; char *s; struct in_conninfo *inc; struct mbuf *mfree; @@ -1521,6 +1524,7 @@ tcp_do_segment(struct mbuf *m, struct tc inc = &tp->t_inpcb->inp_inc; tp->sackhint.last_sack_ack = 0; sack_changed = 0; + nsegs = max(1, m->m_pkthdr.lro_nsegs); /* * If this is either a state-changing packet or current state isn't @@ -1759,7 +1763,7 @@ tcp_do_segment(struct mbuf *m, struct tc /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */ hhook_run_tcp_est_in(tp, th, &to); - TCPSTAT_INC(tcps_rcvackpack); + TCPSTAT_ADD(tcps_rcvackpack, nsegs); TCPSTAT_ADD(tcps_rcvackbyte, acked); sbdrop(&so->so_snd, acked); if (SEQ_GT(tp->snd_una, tp->snd_recover) && @@ -1772,7 +1776,7 @@ tcp_do_segment(struct mbuf *m, struct tc * typically means increasing the congestion * window. */ - cc_ack_received(tp, th, CC_ACK); + cc_ack_received(tp, th, nsegs, CC_ACK); tp->snd_una = th->th_ack; /* @@ -1838,7 +1842,7 @@ tcp_do_segment(struct mbuf *m, struct tc * rcv_nxt. */ tp->rcv_up = tp->rcv_nxt; - TCPSTAT_INC(tcps_rcvpack); + TCPSTAT_ADD(tcps_rcvpack, nsegs); TCPSTAT_ADD(tcps_rcvbyte, tlen); #ifdef TCPDEBUG if (so->so_options & SO_DEBUG) @@ -2570,7 +2574,8 @@ tcp_do_segment(struct mbuf *m, struct tc tp->t_dupacks = 0; else if (++tp->t_dupacks > tcprexmtthresh || IN_FASTRECOVERY(tp->t_flags)) { - cc_ack_received(tp, th, CC_DUPACK); + cc_ack_received(tp, th, nsegs, + CC_DUPACK); if ((tp->t_flags & TF_SACK_PERMIT) && IN_FASTRECOVERY(tp->t_flags)) { int awnd; @@ -2620,7 +2625,8 @@ tcp_do_segment(struct mbuf *m, struct tc } /* Congestion signal before ack. */ cc_cong_signal(tp, th, CC_NDUPACK); - cc_ack_received(tp, th, CC_DUPACK); + cc_ack_received(tp, th, nsegs, + CC_DUPACK); tcp_timer_activate(tp, TT_REXMT, 0); tp->t_rtttime = 0; if (tp->t_flags & TF_SACK_PERMIT) { @@ -2654,7 +2660,8 @@ tcp_do_segment(struct mbuf *m, struct tc * segment. Restore the original * snd_cwnd after packet transmission. */ - cc_ack_received(tp, th, CC_DUPACK); + cc_ack_received(tp, th, nsegs, + CC_DUPACK); u_long oldcwnd = tp->snd_cwnd; tcp_seq oldsndmax = tp->snd_max; u_int sent; @@ -2756,7 +2763,7 @@ process_ACK: KASSERT(acked >= 0, ("%s: acked unexepectedly negative " "(tp->snd_una=%u, th->th_ack=%u, tp=%p, m=%p)", __func__, tp->snd_una, th->th_ack, tp, m)); - TCPSTAT_INC(tcps_rcvackpack); + TCPSTAT_ADD(tcps_rcvackpack, nsegs); TCPSTAT_ADD(tcps_rcvackbyte, acked); /* @@ -2821,7 +2828,7 @@ process_ACK: * control related information. This typically means increasing * the congestion window. */ - cc_ack_received(tp, th, CC_ACK); + cc_ack_received(tp, th, nsegs, CC_ACK); SOCKBUF_LOCK(&so->so_snd); if (acked > sbavail(&so->so_snd)) { Modified: head/sys/netinet/tcp_lro.c ============================================================================== --- head/sys/netinet/tcp_lro.c Thu Aug 25 13:24:11 2016 (r304802) +++ head/sys/netinet/tcp_lro.c Thu Aug 25 13:33:32 2016 (r304803) @@ -392,6 +392,7 @@ tcp_lro_flush(struct lro_ctrl *lc, struc #endif } + le->m_head->m_pkthdr.lro_nsegs = le->append_cnt + 1; (*lc->ifp->if_input)(lc->ifp, le->m_head); lc->lro_queued += le->append_cnt + 1; lc->lro_flushed++; Modified: head/sys/netinet/tcp_var.h ============================================================================== --- head/sys/netinet/tcp_var.h Thu Aug 25 13:24:11 2016 (r304802) +++ head/sys/netinet/tcp_var.h Thu Aug 25 13:33:32 2016 (r304803) @@ -784,7 +784,7 @@ void tcp_pulloutofband(struct socket *, void tcp_xmit_timer(struct tcpcb *, int); void tcp_newreno_partial_ack(struct tcpcb *, struct tcphdr *); void cc_ack_received(struct tcpcb *tp, struct tcphdr *th, - uint16_t type); + uint16_t nsegs, uint16_t type); void cc_conn_init(struct tcpcb *tp); void cc_post_recovery(struct tcpcb *tp, struct tcphdr *th); void cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type); Modified: head/sys/sys/mbuf.h ============================================================================== --- head/sys/sys/mbuf.h Thu Aug 25 13:24:11 2016 (r304802) +++ head/sys/sys/mbuf.h Thu Aug 25 13:33:32 2016 (r304803) @@ -174,6 +174,7 @@ struct pkthdr { #define PH_vt PH_per #define vt_nrecs sixteen[0] #define tso_segsz PH_per.sixteen[1] +#define lro_nsegs tso_segsz #define csum_phsum PH_per.sixteen[2] #define csum_data PH_per.thirtytwo[1] _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
