Attendees: glebius@, rrs@, rscheff@, tuexen@

  * Gleb is suggesting to remove the compressed TCP TIMEWAIT state. The memory savings are limited, memory is not that critical anymore and it would simplify the code and allow further optimizations of the code. glebius@ will reach out to people if there are some objections. It was also discussed which information would be need to reduce the time a TCP connections stays in TIMEWAIT state. One thing he will implement is a counter how many compressed states where used at all. Discussion has been started on net@.
  * ECN implementation has been improved. The code is now contained in one file [[https://cgit.freebsd.org/src/tree/sys/netinet/tcp_ecn.c|tcp_ecn.c]].
  * iSCSI changes [[https://reviews.freebsd.org/D32540|D32540]], [[https://reviews.freebsd.org/D34198|D34198]], [[https://reviews.freebsd.org/D34230|D34230]]. rscheff@ is looking for reviewers.
  * [[https://reviews.freebsd.org/D21011|D21011]] is implementing Accurate ECN and has been updated and will be reviewed by rrs@ and tuexen@.
  * [[https://reviews.freebsd.org/D23230|D23230]] is implementing ECN++.
  * [[https://reviews.freebsd.org/D30043|D30043]] is a small whitespace cleanup.
  * [[https://reviews.freebsd.org/D28822|D28822]] improves PRR, needs some cleanup.
  * There was bug reported on the current@ mailing list. When a TCP client connects to a server running on the same host, but using a global IPv6 address, the transmission and the first retransmission is reported as received on the interface the global IPv6 address is configured on. The second retransmission is reported on the loopback device. This results in dropping the first two packets if the ''%%sysctl%%'' variable ''%%net.inet6.ip6.source_address_validation%%'' is set to 1. The support for this ''%%sysctl%%'' variable was introduced by this [[https://cgit.freebsd.org/src/commit/?id=1817be481b8703ae86730b151a6f49cc3022930f|commit]]. glebius@ and tuexen@ will look into this.
  * The panic rrs@ was observing is not occuring anymore. There is a code path which should not be taken (and might be relevant for this problem), which should never be executed according to a comment from rwatson@ and the understanding of the code by glebius@, rrs@, and tuexen@. tuexen@ will add a panic() under INVARIANTS to figure out if this code path is actually not taken.
  * [[https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=263445|PR 263445]]: The dump looks similar to a bug which was fixed by [[https://reviews.freebsd.org/D33979|D33979]]. However, this fix is in 13.1RC3. rscheff@ will ask for a core dump and if it possible to recreate the problem (once he figures out how to log into the bugtracker).

Next meeting: 05 May 2022 @ 1500 UTC