Jason Xing wrote: > "Timestamping is key to debugging network stack latency. With > SO_TIMESTAMPING, bugs that are otherwise incorrectly assumed to be > network issues can be attributed to the kernel." This is extracted > from the talk "SO_TIMESTAMPING: Powering Fleetwide RPC Monitoring" > addressed by Willem de Bruijn at netdevconf 0x17). > > There are a few areas that need optimization with the consideration of > easier use and less performance impact, which I highlighted and mainly > discussed at netconf 2024 with Willem de Bruijn and John Fastabend: > uAPI compatibility, extra system call overhead, and the need for > application modification. I initially managed to solve these issues > by writing a kernel module that hooks various key functions. However, > this approach is not suitable for the next kernel release. Therefore, > a BPF extension was proposed. During recent period, Martin KaFai Lau > provides invaluable suggestions about BPF along the way. Many thanks > here! > > This series adds the BPF networking timestamping infrastructure through > reusing most of the tx timestamping callback that is currently enabled > by the SO_TIMESTAMPING.. This series also adds TX timestamping support > for TCP. The RX timestamping and UDP support will be added in the future. This series addresses all my feedback. The timestamping patches all have my Reviewed-by. The BPF parts I am less qualified to review. They LGTM, but I defer to Martin as the expert reviewer.
