From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6A7DC433F5 for ; Thu, 14 Apr 2022 15:59:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242943AbiDNQBY (ORCPT ); Thu, 14 Apr 2022 12:01:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359844AbiDNPrZ (ORCPT ); Thu, 14 Apr 2022 11:47:25 -0400 Received: from www62.your-server.de (www62.your-server.de [213.133.104.62]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B611F70FB; Thu, 14 Apr 2022 08:32:54 -0700 (PDT) Received: from sslproxy03.your-server.de ([88.198.220.132]) by www62.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1nf1Se-0006Mb-Q0; Thu, 14 Apr 2022 17:32:44 +0200 Received: from [85.1.206.226] (helo=linux.home) by sslproxy03.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nf1Se-000PQJ-F2; Thu, 14 Apr 2022 17:32:44 +0200 Subject: Re: [RFC PATCH 0/1] sample: bpf: introduce irqlat To: Song Chen References: <1649927240-18991-1-git-send-email-chensong_2000@189.cn> <2e6ee265-903c-2b5c-aefd-ec24f930c999@iogearbox.net> Cc: ast@kernel.org, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, brendan.d.gregg@gmail.com From: Daniel Borkmann Message-ID: Date: Thu, 14 Apr 2022 17:32:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.103.5/26512/Thu Apr 14 10:28:56 2022) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Song, On 4/14/22 1:25 PM, Song Chen wrote: > hi Daniel, > > Thanks for liking the idea. > > My target is embedded devices, that's why i get started from ebpf C.bcc and bpftrace is a good idea, but i prefer taking one thing at a time, what's more, i'm not familiar with python, it might take longer. > > Once C code is accepted, i will move myself to bcc and bpftrace. Is it ok for you? The libbpf-based tools from the mentioned link in BCC are all C, not Python. Also bpftrace has guidelines for building it more portably that would be suitable for embedded devices [2]. I'd presume these should still match your requirements? Right now samples/bpf/ is a bit of a dumping ground of random things, some BPF samples better maintained than others, but generally samples/bpf/ is a bit of a mess. BPF has a huge ecosystem outside of kernel in its various areas it covers, so it has outgrown the few samples in there long ago, and you'll find many resources on how to get started in the wild. Adding this as a samples/bpf/ will have little value to others, since people may not be aware of them, and if they are they need to manually build/ship it, etc. If you upstream and can improve the tools in bpftrace/bcc as pointed out, then a lot more people will be able to consume them and benefit from it, and you get the shipping via distros for free. [2] https://github.com/iovisor/bpftrace/blob/master/docs/embedded_builds.md Thanks again, Daniel > BR > > Song > > > 在 2022/4/14 17:47, Daniel Borkmann 写道: >> On 4/14/22 11:07 AM, Song Chen wrote: >>> I'm planning to implement a couple of ebpf tools for preempt rt, >>> including irq latency, preempt latency and so on, how does it sound >>> to you? >> >> Sounds great, thanks! Please add these tools for upstream inclusion either to bpftrace [0] or >> bcc [1], then a wider range of users would be able to benefit from them as well as they are >> also shipped as distro packages and generally more widely used compared to kernel samples. >> >> Thanks Song! >> >>    [0] https://github.com/iovisor/bpftrace/tree/master/tools >>    [1] https://github.com/iovisor/bcc/tree/master/libbpf-tools >> >>> Song Chen (1): >>>    sample: bpf: introduce irqlat >>> >>>   samples/bpf/.gitignore    |   1 + >>>   samples/bpf/Makefile      |   5 ++ >>>   samples/bpf/irqlat_kern.c |  81 ++++++++++++++++++++++++++++++ >>>   samples/bpf/irqlat_user.c | 100 ++++++++++++++++++++++++++++++++++++++ >>>   4 files changed, 187 insertions(+) >>>   create mode 100644 samples/bpf/irqlat_kern.c >>>   create mode 100644 samples/bpf/irqlat_user.c >>> >> >>