Re: [PATCHv3 bpf-next 03/13] bpf: Add multi kprobe link

[Alexei Starovoitov]

On Wed, Mar 16, 2022 at 01:24:09PM +0100, Jiri Olsa wrote:
> +static int
> +kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
> +			   struct pt_regs *regs)
> +{
> +	int err;
> +
> +	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
> +		err = 0;
> +		goto out;
> +	}

That's a heavy hammer.
It's ok-ish for now, but would be good to switch to
__this_cpu_inc_return(*(prog->active)) at some point.
The way fentry/fexit progs do.