Re: perf BPF/elfdep intermitent build problems

["Wangnan (F)" <wangnan0@huawei.com>]

On 2015/11/19 10:29, Wangnan (F) wrote:
>
>
> On 2015/11/19 10:21, Wangnan (F) wrote:
>>

[SNIP]
>> Right. It should be
>>
>> $ cd tools/lib/bpf
>> $ make clean
>>   CLEAN    libbpf
>>   CLEAN    core-gen
>> $
>>
>>
>> After cleaning can you trigger this problem again?
>>
>
> Tiggered part of your problem:
>
> $ make
>
> Auto-detecting system features:
> ...                        libelf: [ on  ]
> ...                           bpf: [ on  ]
>
>   CC       libbpf.o
>   CC       bpf.o
>   LD       libbpf-in.o
>   LINK     libbpf.a
>   LINK     libbpf.so
> $ make clean
>   CLEAN    libbpf
>   CLEAN    core-gen
> $ make clean
>
> Auto-detecting system features:
> ...                        libelf: [ on  ]
> ...                           bpf: [ on  ]
>
>   CLEAN    libbpf
>   CLEAN    core-gen
>
> Feature check would be triggered the second time we make clean.
>
> Will look into it.
>

I understand this part of the problem.

There's no way for tools/build/Makefile.feature knowing whether
we are doing 'make clean' or 'make'. Therefore, even for
'make clean' those feature tests are mandatory to take action.

I posted a patch for it. Please see:

http://lkml.kernel.org/g/1447922706-99905-1-git-send-email-wangnan0@huawei.com

Thank you.