Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [RFC PATCH] samples:bpf: introduce task detector
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrii Nakryiko <andriin@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@chromium.org>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:BPF (Safe dynamic programs and tools)" 
        <netdev@vger.kernel.org>,
        "open list:BPF (Safe dynamic programs and tools)" 
        <bpf@vger.kernel.org>
References: <6561a67d-6dac-0302-8590-5f46bb0205c2@linux.alibaba.com>
 <CAEf4BzYwO59x0kJWNk1sfwKz=Lw+Sb_ouyRpx8-v1x8XFoqMOw@mail.gmail.com>
From:   =?UTF-8?B?546L6LSH?= <yun.wang@linux.alibaba.com>
Message-ID: <9a78329c-8bfe-2b83-b418-3de88e972c5a@linux.alibaba.com>
Date:   Thu, 28 May 2020 16:14:43 +0800
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:68.0)
 Gecko/20100101 Thunderbird/68.8.0
MIME-Version: 1.0
In-Reply-To: <CAEf4BzYwO59x0kJWNk1sfwKz=Lw+Sb_ouyRpx8-v1x8XFoqMOw@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi, Andrii

Thanks for your comments :-)

On 2020/5/28 下午2:36, Andrii Nakryiko wrote:
[snip]
>> ---
> 
> I haven't looked through implementation thoroughly yet. But I have few
> general remarks.
> 
> This looks like a useful and generic tool. I think it will get most
> attention and be most useful if it will be part of BCC tools. There is
> already a set of generic tools that use libbpf and CO-RE, see [0]. It
> feels like this belongs there.
> 
> Some of the annoying parts (e.g., syscall name translation) is already
> generalized as part of syscount tool PR (to be hopefully merged soon),
> so you'll be able to save quite a lot of code with this. There is also
> a common build infra that takes care of things like vmlinux.h, which
> would provide definitions for all those xxx_args structs that you had
> to manually define.
> 
> With CO-RE, it also will allow to compile this tool once and run it on
> many different kernels without recompilation. Please do take a look
> and submit a PR there, it will be a good addition to the toolkit (and
> will force you write a bit of README explaining use of this tool as
> well ;).

Aha, I used to think bcc only support python and cpp :-P

I'll try to rework it and submit PR, I'm glad to know that you think
this tool as a helpful one, we do solved some tough issue with it
already.

> 
> As for the code itself, I haven't gone through it much, but please
> convert map definition syntax to BTF-defined one. The one you are
> using is a legacy one. Thanks!
> 
>   [0] https://github.com/iovisor/bcc/tree/master/libbpf-tools

Will check the example there :-)

Regards,
Michael Wang

> 
>>  samples/bpf/Makefile             |   3 +
>>  samples/bpf/task_detector.h      | 382 +++++++++++++++++++++++++++++++++++++++
>>  samples/bpf/task_detector_kern.c | 329 +++++++++++++++++++++++++++++++++
>>  samples/bpf/task_detector_user.c | 314 ++++++++++++++++++++++++++++++++
>>  4 files changed, 1028 insertions(+)
>>  create mode 100644 samples/bpf/task_detector.h
>>  create mode 100644 samples/bpf/task_detector_kern.c
>>  create mode 100644 samples/bpf/task_detector_user.c
>>
> 
> [...]
>