Re: [OE-core] [PATCH 2/2] lz4: use CFLAGS from bitbake

["Mikko Rapeli" <mikko.rapeli@bmw.de>]

On Thu, Apr 22, 2021 at 08:05:20AM -0700, Khem Raj wrote:
> On Thu, Apr 22, 2021 at 7:42 AM Mikko Rapeli <mikko.rapeli@bmw.de> wrote:
> 
> > Currently lz4 uses it's own defaults which include O3 optimization.
> > Switch from O3 to bitbake default O2 reduces binary package size
> > from 467056 to 331888 bytes. Enables also building with Os if needed.
> 
> 
> These could impact runtime performance have you
> Checked what the rough impact is ?

Nope, have not checked this. I've build my targets with this patch
and have not noticed any major performance regression. If there is
a performance problem, then I'd rather see O3 explicitly set in the recipe,
for example for native target.

> Secondly we will be using non default set which could result in errors less
> seen by others over time I have realized it’s also good to open a dialog
> upstream and get the reasoning behind not letting distro defaults apply
> some packages do have valid reasons

I've seen bugs with O3 optimziation level too on some target archs.
I would not enable that by default. But I do understand your concern.

In similar ways, I was checking ffmpeg, attr, acl etc which were defaulting
to O3 in older versions but with new poky master versions now behave well
and use bitbake default O2. I guess there too no major performance regressions
have been detected.

Cheers,

-Mikko