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

Alexey Budankov
2018-10-08T11:55:44Z

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
>