minutes: IO Visor/TSC Dev Meeting

Brenden Blanco

Hi all,

Thanks for joining the call today. As usual, here are my notes from the

=== Discussion ===
LSF/MM - BPF track
* overall went quite well
* planning BPF conference for next year
* notes @

* Compiler work to support compile-once-run-anywhere
* LLVM code review fabricator - search for yonghong to find patch
* Send signal bpf helper RFC1 has some issues
* trying instead to send to current, even if in interrupt context
* Other updates: some work for map of maps support in bcc

* Some progress on bounded loop
* Performing arithmetic on induction variables in one pass through loop
* Many loops have simple enough induction variable strides to satisfy this
simple algorithm
* other sockmap and ktls fixes
* release/acquire socket lock issue in ktls
* fuzzing fixes

* 32 bit patchset work continues
* Currently determining how to test
* Setting up arm 32 bit qemu environment has issues
* Cross-compiling kernel + selftest suite
* Some offers to test on 32 bit x86

* BPF book is currently being reviewed
* If someone on the call would like to contribute reviews, reach out to
* bpftrace syntax to be finalized
* some compiler hints would be nice to pass __user pointer annotation to the
scripts, otherwise explicit wrapper is necessary
* necessary only for mixed mode tools

* socket_assign helper for proxying support in bpf
* tproxy working for tcp, working on udp
* skc_lookup[_tcp] helper needed?
* some leakiness in the socket api/bpf abstraction, needs to be worked out

* Out of bounds fix
* cgroups hooks for sendmsg
* breaks for DNS
* add recvmsg hooks for reverse path, to avoid lookup failure
* some minor fixes for connected (tcp) case

* Improving libbpf for BTF (and in prior kernels)
* BTF to C converter
* next: using BTF to define bpf maps

=== Attendees ===
Alexei Starovoitov
Andrii Nakryiko
Augusto Caringi
Dan Siemon
Jesper Brouer
Richard Elling
Brenden Blanco
Yonghong Song
Andy Gospodarek
Daniel Borkmann
Jakub Kicinski
Brendan Gregg
John Fastabend
Mauricio Vasquez
Paul Chaignon
Joe Stringer