Subject: Re: [PATCH v4 perf,bpf 15/15] perf, bpf: save information about short living bpf programs

From: Jiri Olsa <[email-masked]>
Date: Wed, 27 Feb 2019 14:21:16 +0100

On Mon, Feb 25, 2019 at 04:20:19PM -0800, Song Liu wrote:

SNIP

> +	btf_id = info_linear->info.btf_id;
> +
> +	info_node = malloc(sizeof(struct bpf_prog_info_node));
> +	if (info_node) {
> +		info_node->info_linear = info_linear;
> +		perf_env__insert_bpf_prog_info(env, info_node);
> +	} else
> +		free(info_linear);
> +
> +	if (btf_id == 0)
> +		goto out;
> +
> +	if (btf__get_from_id(btf_id, &btf)) {
> +		pr_debug("%s: failed to get BTF of id %u, aborting\n",
> +			 __func__, btf_id);
> +		goto out;
> +	}
> +	perf_env__fetch_btf(env, btf_id, btf);

so is this the main reason we are doing this? getting the btf
data for bpf prog ids and store them?

please describe the whole bpf events/features data flow in
changelog as I asked in previous email

thanks,
jirka