• cc@
• olivier@
• rrs@
• rscheff@
• tuexen@

• 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 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.
• D28822 improves PRR. rrs@ and tuexen@ will review.
• D39299 improves compliance to RFC 6675 with regard to the isLost variable. rrs@ and cc@ will review it. cc@ tested in Emulab.
• tuexen@ is working on fixing the DSCP setting for TCP/IPv6, The test suite will be updated to catch all code paths and then the fix will be put up for review. tuexen@ will notify olivier@, once the test suite has been updated.
• tuexen@ is working on fixing MD5 support for RACK to address PR253096. For proper testing, TCP-MD5 support will be added to packetdrill. BBR will also be tested.
• cc@ wants review on D40061, D39848. tuexen@ will review it.
• rscheff@ has received a patch from VMWare for cc_cubic. rscheff@ will split it up in small patches and brings them for review. cc@ will provide a first patch to address the original issue reported by VMWare.
• rrs@ reports that CUBIC has a problem in combination with RACK. rrs@ will put up a patch for review.
• It was discussed whether RACK and BBR can be build by default. rrs@ will talk to jtl@, who was pushing back in the past.
• 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: D36303. rrs@ will review it and implement it for the rack stack.
• 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.

01 June 2023 @ 1500 UTC