24August2023 [FreeBSD WIKI]

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====== Attendees ======
  * cc@
  * glebius@
  * peterlei@
  * rscheff@
  * tuexen@

====== Ongoing Short Term Projects ======
  * glebius@ asks whether it makes sense to improve the TCP timer precision. tuexen@ states that this is very useful for testing purposes. glebius@ will provide a patch to tuexen@ for testing and tuexen@ will provide feedback, if such a patch us useful for %%FreeBSD%% in general. This applies to the default stack only, not the the RACK or BBR stack, which uses HPTS for timers. Setting the ''%%sysctl%%'' variable ''%%kern.timecounter.alloweddeviation%%'' to zero allows the timers to run of very precisely, which is useful when running ''%%packetdrill%%''. However, it affects the overall system performance.
  * At least for testing purposes (packetdrill) it would be good to have LRO support for tun interfaces. tuexen@ suggested to generalize LRO to not depend on an Ethernet header being present. gallatin@ prefers to not make the LRO code more complex, since it most likely will impact the performance. tjh@ has [[https://reviews.freebsd.org/D37437|D37437]] under review, which allows the tun interface to add an Ethernet header. tuexen@ will test this to see if it can also be used to enable LRO for the tun interface. This seems netmap specific. tuexen@ will consider to use tap interfaces in packetdrill.
  * [[https://reviews.freebsd.org/D28822|D28822]] improves PRR. rrs@ and tuexen@ will review. Will be committed after stable/14 is branched.
  * [[https://reviews.freebsd.org/D39299|D39299]] improves compliance to [[https://www.rfc-editor.org/rfc/rfc6675|RFC 6675]] with regard to the ''%%isLost%%'' variable. rrs@ and cc@ will review it. cc@ tested in Emulab. Will be committed after stable/14 is branched.
  * BBLog is missing a man page. tuexen@ will write one.
  * tuexen@ will add tests for handling RST ACK segments in all states and test the base, RACK and BBR stack.

====== Ongoing Longer Term Projects ======
  * It was discussed whether RACK and BBR can be build by default. RACK will be enabled in after stable/14 has been branched. It will be discussed with security@ and announced on mailing lists first.
  * It was discussed that it would be a good idea to move the freebsd stack from ticks to micro seconds.
  * rscheff@ is improving %%AccECN%% code: [[https://reviews.freebsd.org/D36303|D36303]]. rrs@ will review it and implement it for the rack stack.
  * [[https://reviews.freebsd.org/D23230|D23230]] is implementing ECN++. rrs@ will review it.
  * tuexen@ wants to write a tool which dumps the BBLog information of a TCP endpoint from a life system or a core. Using ''%%kvm_read()%%'' has drawbacks as glebius@ pointed out, using a python kgdb script may be an alternative. An alternative is to write a python kgdb script which pumps data into ''%%tcplog_dumper%%''. This would allow to minimize code duplication. @glebius will try to work on this soon.
  * tuexen@ was asking about the semantics of ''%%pr_disconnect()%%'' and ''%%pr_close()%%''. They are called right after each other. tuexen@ will look at potential cleanups.

====== Next Meeting ======
07 September 2023 @ 1500 UTC