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minutes: IO Visor TSC/Dev Meeting

Brenden Blanco
 

Hi All,

Thanks for attending the meeting today. As usual, here are my notes.

=== Discussion ===

Brenden:
- working on fc28 packaging
- pr available
- includes some python3 fixes
- not to be included in next release tag :(
- v0.6.0 tagged

Yonghong:
- Some rewriter changes, working with Paul
- 4.17 changed some syscall parameters
- some fixes in bcc, when __syscall prefix is seen
- tracepoint structure bugfix
- introduce option to change license option

Alexei:
- bcc release schedule
- want to release within short timeframe of kernel release
- have tried to keep backwards compatible, but still highly dependent on
kernel

Saeed:
- xdp offloads update
- working on examples for using the new api/metadata
- perf numbers to be published after that
- currently experimenting with dynamic hw metadata
- e.g.: vlan, csum complete, hash, flow tag
- can hardware provide offsets to tcp data as a new metadata field?

Okash:
- BTF
- some WIP patches for pretty printing maps, currently for array maps

John:
- sockhash fixes from fuzzbot
- bugs in locking and ipv6 ports
- Working on RFC for bounded loop support
- need to expand from finding loop induction vars to all induction vars
- llvm likes to build nested loops, and always jumps with a conditional in
the middle, makes finding loop induction variables hard
- also important to add overflow checks
- possible to modify llvm to make verifying easier?
- annotations? how to rely on them for safety...
- introduce rep counter
- more crazy ideas discussed - pass SSA, dom tree info to verifier

Brendan:
- bcc+btf support?
- not yet, still working on dwarf->btf converter
- pahole has some gaps to be able to convert kernel dwarf
- probably good enough though


=== Attendees ===
Brenden Blanco
Opher
Bjorn Topel
Marco Leogrande
Martin Lau
Nic Viljoen
Saeed
Jakub Kicinski
George
Jesper Brouer
Alexander Duyck
Quentin Monnet
Daniel Borkmann
William Tu
Yonghong Song
Brendan Gregg
Yifeng Sun
John Fastabend
Okash