From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751329AbbGQEPX (ORCPT ); Fri, 17 Jul 2015 00:15:23 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:57750 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750735AbbGQEPW (ORCPT ); Fri, 17 Jul 2015 00:15:22 -0400 Message-ID: <55A88137.7020609@huawei.com> Date: Fri, 17 Jul 2015 12:14:47 +0800 From: "Wangnan (F)" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Alexei Starovoitov , He Kuang , pi3orama , Namhyung Kim CC: "rostedt@goodmis.org" , "masami.hiramatsu.pt@hitachi.com" , "acme@kernel.org" , "a.p.zijlstra@chello.nl" , "mingo@redhat.com" , "jolsa@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH v4 3/3] bpf: Introduce function for outputing data to perf event References: <1436522587-136825-1-git-send-email-hekuang@huawei.com> <1436522587-136825-4-git-send-email-hekuang@huawei.com> <55A042DC.6030809@plumgrid.com> <55A3404B.6020904@huawei.com> <20150713135223.GB9917@danjae.kornet> <4D441676-21A7-46EE-AAB0-EB529D408082@163.com> <20150713140915.GD9917@danjae.kornet> <55A46928.9090708@plumgrid.com> <55A4F869.1020705@huawei.com> <55A88085.8090407@plumgrid.com> In-Reply-To: <55A88085.8090407@plumgrid.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.66.109] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/7/17 12:11, Alexei Starovoitov wrote: > On 7/14/15 4:54 AM, He Kuang wrote: >>> I'm not sure llvm generates proper dwarf along with bpf code (I didn't >>> test that part. If there are any issues they should be fixable. If you >>> can prepapre a patch for llvm that would be even better :) >>> >> >> I found objdump can't get dwarf info from bpf object file: >> >> $ objdump --dwarf=info bpf.o >> bpf.o: file format elf64-little >> >> $ readelf -a bpf.o |grep debug_info >> > > yeah. looks like this part is not working. > Interesting that when I do: clang -O2 -target bpf a.c -g -S > there is some minimal debug info in the .s, but .o lacks > debuginfo completely. Digging further... Glad to see you start look at it. We are not familiar with LLVM, but I was told that LLVM has a clean structure and very easy to introduce new features. Could you please give us some hits on it so we can work together? Thank you.