Re: [PATCH] perf tools: Fix cross compiling error

Adrian Hunter
2015-08-31T14:05:32Z

On 31/08/15 17:02, Jiri Olsa wrote:
> On Mon, Aug 31, 2015 at 10:54:51AM -0300, Arnaldo Carvalho de Melo wrote:
>> Em Fri, Aug 28, 2015 at 12:54:02PM +0000, Wang Nan escreveu:
>>> Cross compiling perf to other platform failed due to missing symbol:
>>>
>>> ...
>>> AR /pathofperf/libperf.a
>>> LD /pathofperf/tests/perf-in.o
>>> LD /pathofperf/perf-in.o
>>> LINK /pathofperf/perf
>>> /pathofperf/libperf.a(libperf-in.o): In function `intel_pt_synth_branch_sample':
>>> /usr/src/kernel/tools/perf/util/intel-pt.c:899: undefined reference to `tsc_to_perf_time'
>>> /pathofperf/libperf.a(libperf-in.o): In function `intel_pt_synth_transaction_sample':
>>> /usr/src/kernel/tools/perf/util/intel-pt.c:992: undefined reference to `tsc_to_perf_time'
>>> /pathofperf/libperf.a(libperf-in.o): In function `intel_pt_synth_instruction_sample':
>>> /usr/src/kernel/tools/perf/util/intel-pt.c:943: undefined reference to `tsc_to_perf_time'
>>> ...
>>>
>>> This is because we allow newly introduced intel-pt-decoder to be
>>> compiled to not only X86, but tsc.c which required by it is compiled
>>> for x86 only.
>>>
>>> This patch fix the compiling error by allow tsc.c to be compiled if
>>> CONFIG_AUXTRACE is set, no matter the target platform.
>>
>> There were some changes in this area, i.e. x86 needs tsc, and auxtrace
>> as well, so both should express that via:
>>
>> libperf-$(CONFIG_X86) += tsc.o
>> libperf-$(CONFIG_AUXTRACE) += tsc.o
>>
>> Because on !x86 we want to process perf.data files containing Intel PT.
>>
>> Adding Jiri and Adrian to the CC list.
>>
>> - Arnaldo
>>
>>> Signed-off-by: Wang Nan <wangnan0@huawei.com>
>>> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
>>> ---
>>> tools/perf/util/Build | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
>>> index fd2f084..c8d9c7e 100644
>>> --- a/tools/perf/util/Build
>>> +++ b/tools/perf/util/Build
>>> @@ -74,7 +74,7 @@ libperf-y += stat-shadow.o
>>> libperf-y += record.o
>>> libperf-y += srcline.o
>>> libperf-y += data.o
>>> -libperf-$(CONFIG_X86) += tsc.o
>>> +libperf-$(CONFIG_AUXTRACE) += tsc.o
>
> hum, didn't you guys want to change it like this:
>
> libperf-$(CONFIG_X86) += tsc.o
> libperf-$(CONFIG_AUXTRACE) += tsc.o
>
> thats why I made that fix for duplicates objects in obj-y:
> 0bdede8a3e4f tools build: Allow duplicate objects in the object list

Yes. I need to send V2 of my original patch "perf tools: Fix build on
powerpc broken by pt/bts". Will do shortly.