Re: Can perf record make buildid-mmap the default

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Nov 04, 2024 at 10:25:53AM +0000, James Clark wrote:
> 
> 
> On 03/11/2024 6:03 am, Ian Rogers wrote:
> > Hi,
> > 
> > Without command line flags perf record will post process samples
> > adding DSO buildid events with samples it will also populate the
> > buildid cache. The --buildid-mmap option is superior as mmap events
> > have buildids within them and the buildid cache isn't generated. As
> > buildid-mmap has been available since 5.12, a full major release, can
> > we just make its defaults the defaults for perf record?
> > 
> > Thanks,
> > Ian
> > 
> 
> There's already the perf_can_record_build_id() check when it's requested, so
> seems easy enough to have it on by default only when it's supported.

Probably we can move it to the missing feature detection and enable it
by default.

Thanks,
Namhyung

> 
> Ubuntu 20 is still in support and on 5.4 kernel so there could be a small
> potential to break someones workflow if we had it on unconditionally.
> 
> 
> 
>