> On 26. Jan 2021, at 16:09, Richard Scheffenegger <[email protected]> wrote: > > The branch main has been updated by rscheff: > > URL: > https://cgit.FreeBSD.org/src/commit/?id=6a376af0cd212be4e16d013d35a0e2eec1dbb8ae > > commit 6a376af0cd212be4e16d013d35a0e2eec1dbb8ae > Author: Richard Scheffenegger <[email protected]> > AuthorDate: 2021-01-26 15:06:32 +0000 > Commit: Richard Scheffenegger <[email protected]> > CommitDate: 2021-01-26 15:06:32 +0000 > > TCP PRR: Patch div/0 in tcp_prr_partialack > > With clearing of recover_fs in bc7ee8e5bc555, div/0 > was observed while processing partial_acks. > > Suspect that rewind of an erraneous RTO may be > causing this - with the above change, recover_fs > would no longer retained at the last calculated > value, and reset. But CC_RTO_ERR can reenable > IN_RECOVERY(), without setting this again. > > Adding a safety net prior to the division in that > function, which I missed in D28114. Any plans to MFC this to stable/13?
This commit intends to address an issue reported by mm@ in https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=252958 Best regards Michael > --- > sys/netinet/tcp_input.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c > index 4b8f91ed9d0b..459b78cd444a 100644 > --- a/sys/netinet/tcp_input.c > +++ b/sys/netinet/tcp_input.c > @@ -510,7 +510,6 @@ cc_post_recovery(struct tcpcb *tp, struct tcphdr *th) > } > /* XXXLAS: EXIT_RECOVERY ? */ > tp->t_bytes_acked = 0; > - tp->sackhint.recover_fs = 0; > } > > /* > @@ -3948,10 +3947,13 @@ tcp_prr_partialack(struct tcpcb *tp, struct tcphdr > *th) > /* > * Proportional Rate Reduction > */ > - if (pipe > tp->snd_ssthresh) > + if (pipe > tp->snd_ssthresh) { > + if (tp->sackhint.recover_fs == 0) > + tp->sackhint.recover_fs = > + max(1, tp->snd_nxt - tp->snd_una); > snd_cnt = (tp->sackhint.prr_delivered * tp->snd_ssthresh / > tp->sackhint.recover_fs) - tp->sackhint.sack_bytes_rexmit; > - else { > + } else { > if (V_tcp_do_prr_conservative) > limit = tp->sackhint.prr_delivered - > tp->sackhint.sack_bytes_rexmit; _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/dev-commits-src-all To unsubscribe, send any mail to "[email protected]"
