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

[Alexei Starovoitov]

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.