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

From: Jiri Olsa
Date: Mon Oct 08 2018 - 11:13:06 EST


On Mon, Oct 08, 2018 at 05:43:38PM +0300, Alexey Budankov wrote:
> Hi,
>
> On 08.10.2018 15:38, Jiri Olsa wrote:
> > On Mon, Oct 08, 2018 at 03:03:18PM +0300, Alexey Budankov wrote:
> <SNIP>
> >>
> >> Well, let's go with stub functions design as opposite to pure
> >> conditional compilation. However this may, probably, result in
> >> unintended Perf tool binary size growth, even if NO_AIO is
> >> defined during compilation.
> >
> > hum, empty functions are be optimized out
>
> Yes, but there will be references to stubs in else branch of
> record__mmap_read_evlist() so I am not sure that *all* compilers
> are smart enough to recognize and still optimize it out.

well, kernel is doing that and it seem to be fine,
so I wouldn't worry about it

jirka