Re: [PATCH v11 1/3]: perf util: map data buffer for preserving collected data

[Alexey Budankov <alexey.budankov@linux.intel.com>]

Hi,

On 08.10.2018 13:50, Jiri Olsa wrote:
> On Mon, Oct 08, 2018 at 09:14:29AM +0300, Alexey Budankov wrote:
>>
<SNIP>
>> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
>> index f6d1a03c7523..2e90f4ce9214 100644
>> --- a/tools/perf/Makefile.config
>> +++ b/tools/perf/Makefile.config
>> @@ -355,6 +355,11 @@ endif # NO_LIBELF
>>  
>>  ifeq ($(feature-glibc), 1)
>>    CFLAGS += -DHAVE_GLIBC_SUPPORT
>> +  ifndef NO_AIO
> 
> hum, do we need NO_AIO? we have the --aio option to enable that right?

Right. Enable that *in runtime*.

> I guess BIONIC does not support aio, but but will it fail when it's
> compiled in there?

Please see updated section of the cover letter for more information 
regarding this. Possible compilation issues is that's why we better 
have this capability in advance:
  
  objdump -T tools/perf/perf | grep aio

  0000000000000000      DF *UND*	0000000000000000  GLIBC_2.2.5 aio_suspend64
  0000000000000000      DF *UND*	0000000000000000  GLIBC_2.2.5 aio_return64
  0000000000000000      DF *UND*	0000000000000000  GLIBC_2.2.5 aio_error64
  0000000000000000      DF *UND*	0000000000000000  GLIBC_2.2.5 aio_write64

IMHO, it is worth implementing NO_AIO define.

Thanks,
Alexey

> 
> jirka
> 
>> +    ifndef BIONIC
>> +        CFLAGS += -DHAVE_AIO_SUPPORT
>> +    endif
>> +  endif
>>  endif
> 
> SNIP
>