Re: [PATCH bpf-next 3/3] selftest/bpf: add BPF triggring benchmark

[Alexei Starovoitov <ast@xxxxxx>]

On 5/8/20 12:05 AM, Andrii Nakryiko wrote:
> base      :    9.200 ± 0.319M/s
> fentry    :    8.955 ± 0.241M/s

> +SEC("fentry/__x64_sys_getpgid")
> +int bench_trigger_fentry(void *ctx)
> +{
> +	__sync_add_and_fetch(&hits, 1);
> +	return 0;
> +}

adding 'lock xadd' is not cheap.
I wonder how much of the delta come from it and from the rest of
trampoline.