Subject: Re: [PATCH v5 perf,bpf 08/15] perf, bpf: save btf in a rbtree in perf_env

From: Jiri Olsa <[email-masked]>
Date: Mon, 4 Mar 2019 14:52:31 +0100

On Wed, Feb 27, 2019 at 09:06:36PM -0800, Song Liu wrote:
> btf contains information necessary to annotate bpf programs. This patch
> saves btf for bpf programs loaded in the system.
> 
> Signed-off-by: Song Liu <[email-masked]>
> ---
>  tools/perf/util/bpf-event.c | 24 ++++++++++++++
>  tools/perf/util/bpf-event.h |  7 ++++
>  tools/perf/util/env.c       | 65 +++++++++++++++++++++++++++++++++++++
>  tools/perf/util/env.h       |  4 +++
>  4 files changed, 100 insertions(+)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index ce81b2c43a51..370b830f2433 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -34,6 +34,29 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
>  	return 0;
>  }
>  
> +static int perf_env__fetch_btf(struct perf_env *env,
> +			       u32 btf_id,
> +			       struct btf *btf)
> +{
> +	struct btf_node *node;
> +	u32 data_size;
> +	const void *data;
> +
> +	data = btf__get_raw_data(btf, &data_size);
> +
> +	node = malloc(data_size + sizeof(struct btf_node));
> +
> +	if (!node)
> +		return -1;
> +
> +	node->id = btf_id;
> +	node->data_size = data_size;
> +	memcpy(node->data, data, data_size);

why don't we store just struct btf itself?

thanks,
jirka