On Sat, Sep 18, 2021 at 02:35:20PM +0200, Jan Klemkow wrote: > The following diff removes the every 2nd ACK feature again and ensures > that we send out an ACK if soreceive() empties the receive buffer.
Looks good in my perform tests, 22% tcp throughput increase. http://bluhm.genua.de/perform/results/2021-09-20T11:05:31Z/perform.html http://bluhm.genua.de/perform/results/2021-09-20T11:05:31Z/gnuplot/tcp.html > We are so close to 7.0, that I would suggest to commit this after the > release. Thus, we don't risk another last minute regression. > > OK? OK bluhm@ post 7.0 > Index: netinet/tcp_input.c > =================================================================== > RCS file: /cvs/src/sys/netinet/tcp_input.c,v > retrieving revision 1.370 > diff -u -p -r1.370 tcp_input.c > --- netinet/tcp_input.c 9 Aug 2021 17:03:08 -0000 1.370 > +++ netinet/tcp_input.c 18 Sep 2021 07:53:45 -0000 > @@ -176,8 +176,7 @@ do { \ > struct ifnet *ifp = NULL; \ > if (m && (m->m_flags & M_PKTHDR)) \ > ifp = if_get(m->m_pkthdr.ph_ifidx); \ > - if (TCP_TIMER_ISARMED(tp, TCPT_DELACK) || \ > - (tcp_ack_on_push && (tiflags) & TH_PUSH) || \ > + if ((tcp_ack_on_push && (tiflags) & TH_PUSH) || \ > (ifp && (ifp->if_flags & IFF_LOOPBACK))) \ > tp->t_flags |= TF_ACKNOW; \ > else \ > Index: netinet/tcp_usrreq.c > =================================================================== > RCS file: /cvs/src/sys/netinet/tcp_usrreq.c,v > retrieving revision 1.181 > diff -u -p -r1.181 tcp_usrreq.c > --- netinet/tcp_usrreq.c 30 Apr 2021 13:52:48 -0000 1.181 > +++ netinet/tcp_usrreq.c 18 Sep 2021 07:53:45 -0000 > @@ -329,8 +329,15 @@ tcp_usrreq(struct socket *so, int req, s > * template for a listening socket and hence the kernel > * will panic. > */ > - if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) != 0) > + if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) != 0) { > + /* > + * If soreceive() empty the receive buffer, we have to > + * send a window update. > + */ > + if (so->so_rcv.sb_cc == 0) > + tp->t_flags |= TF_ACKNOW; > (void) tcp_output(tp); > + } > break; > > /*
