Re: [RFC PATCH 21/22] perf bpf: probe at kprobe points.

From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Wang Nan <wangnan0@huawei.com>,
	ast@plumgrid.com, davem@davemloft.net, acme@kernel.org,
	mingo@redhat.com, a.p.zijlstra@chello.nl, jolsa@kernel.org
Cc: lizefan@kernel.org, linux-kernel@vger.kernel.org,
	pi3orama@163.com, hekuang@huawei.com
Subject: Re: [RFC PATCH 21/22] perf bpf: probe at kprobe points.
Date: Wed, 06 May 2015 01:34:14 +0900	[thread overview]
Message-ID: <5548F106.3010902@hitachi.com> (raw)
In-Reply-To: <1430391165-30267-22-git-send-email-wangnan0@huawei.com>

At least we need a description what this patch does... what will be
done with this patch, and what the user will see and what/how they can do.

Thank you,

On 2015/04/30 19:52, Wang Nan wrote:
> ---
>  tools/perf/util/bpf-loader.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
> index 208f5e8..186a3d0 100644
> --- a/tools/perf/util/bpf-loader.c
> +++ b/tools/perf/util/bpf-loader.c
> @@ -952,8 +952,26 @@ out:
>  	return -1;
>  }
>  
> +static int bpf_probe(void)
> +{
> +	int err = add_perf_probe_events(params.event_array,
> +					params.nr_events,
> +					MAX_PROBES, 0);
> +	/* add_perf_probe_events return negative when fail */
> +	if (err < 0)
> +		pr_err("bpf probe: failed to probe events\n");
> +
> +	return err < 0 ? err : 0;
> +}
> +
>  int bpf__run(void)
>  {
> +	int err;
> +
> +	pr_debug("bpf: probing\n");
> +	if ((err = bpf_probe()))
> +		return err;
> +
>  	pr_info("BPF is running. Use Ctrl-c to stop.\n");
>  	while(1)
>  		sleep(1);
> 

-- 
Masami HIRAMATSU
Linux Technology Research Center, System Productivity Research Dept.
Center for Technology Innovation - Systems Engineering
Hitachi, Ltd., Research & Development Group
E-mail: masami.hiramatsu.pt@hitachi.com