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

Jiri Olsa
2018-10-08T12:37:28Z

On Mon, Oct 08, 2018 at 02:55:13PM +0300, Alexey Budankov wrote:
> 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.

ok, if there are c libs that won't compile with that,
then sure, we need it

thanks,
jirka