Re: [RFC PATCH v4 3/3] bpf: Introduce function for outputing data to perf event

From	"Wangnan (F)" <wangnan0@huawei.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH v4 3/3] bpf: Introduce function for outputing data to perf event
Date	2015-07-17 06:20 +0200
Message-ID	<pN5hU-2OF-3@gated-at.bofh.it> (permalink)
References	(6 earlier) <pLMKl-64q-11@gated-at.bofh.it> <pLN3I-6be-17@gated-at.bofh.it> <pLXw7-4lA-5@gated-at.bofh.it> <pM72q-1HL-15@gated-at.bofh.it> <pN5hU-2OF-5@gated-at.bofh.it>
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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
>>    <EMPTY>
>
> 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.

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Re: [RFC PATCH v4 3/3] bpf: Introduce function for outputing data  to perf event "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-17 06:20 +0200
  Re: [RFC PATCH v4 3/3] bpf: Introduce function for outputing data to  perf event Alexei Starovoitov <ast@plumgrid.com> - 2015-07-17 06:30 +0200

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