Re: [RFC 2/2] perf-stat: enable counting events for BPF programs

[Song Liu]

> On Nov 23, 2020, at 3:47 PM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:

[...]

> 
> I still need to review this deeply, but so far I'm getting this error:
> 
> 	# ./perf stat -b 40
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: elf: skipping unrecognized data section(9) .eh_frame
> 	libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
> 	libbpf: XXX is not found in vmlinux BTF
> 	libbpf: failed to load object 'bpf_prog_profiler_bpf'
> 	libbpf: failed to load BPF skeleton 'bpf_prog_profiler_bpf': -2
> 	libbpf: Can't get the 0th fd from program fentry_XXX: only -1 instances
> 	libbpf: prog 'fentry_XXX': can't attach before loaded
> 	libbpf: failed to auto-attach program 'fentry_XXX': -22

I cannot reproduce this. Is 40 a valid BPF program ID? Could you please share 
more information about it with "bpftool prog show id 40"?

Thanks,
Song