net_buffer_tuner.so was failing to load BTF due to a failure to find netdev_max_backlog ksym.
netdev_max_backlog was an int prior to 6.9 then it got added to a netdev hotpath struct; rather than using it in calculations retrieve the sysctl value and set a bpf global for use in bpf prog context; update it in userspace when we bump sysctl value.
net_buffer_tuner.so was failing to load BTF due to a failure to find netdev_max_backlog ksym.
netdev_max_backlog was an int prior to 6.9 then it got added to a netdev hotpath struct; rather than using it in calculations retrieve the sysctl value and set a bpf global for use in bpf prog context; update it in userspace when we bump sysctl value.
Reported-by: HippieMitch https://github.com/HippieMitch