Re: [PATCH] tracing: bpf: Hide bpf trace events when they are not used

[Steven Rostedt]

On Thu, 12 Oct 2017 18:38:36 -0700
Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote:

> actually just noticed that xdp tracepoints are not covered by ifdef.
> They depend on bpf_syscall too. So probably makes sense to wrap
> them together.
> bpf tracepoints are not being actively worked on whereas xdp tracepoints
> keep evolving quickly, so the best is probalby to go via net-next
> if you don't mind.

Hmm, they didn't trigger a warning, with the exception of
trace_xdp_redirect_map. I have code to check if tracepoints are used or
not, and it appears that the xdp can be used without BPF_SYSCALL.

I don't think they should be wrapped together until we know why they
are used. I can still take this patch and just not touch the xdp ones.

Note, my kernel was using trace_xdp_redirect_map_err,
trace_xdp_redirect_err, trace_xdp_redirect and trace_xdp_exception.

As they did appear.

-- Steve