Re: [dpdk-dev] [PATCH] config: change default cache line size for ARMv8 with meson

[Luca Boccassi <bluca@debian.org>]

On Wed, 2019-01-09 at 15:34 +0000, Jerin Jacob Kollanukkaran wrote:
> > > Please check below thread and patch.
> > > 
> > > http://mails.dpdk.org/archives/dev/2019-January/122676.html
> > > https://patches.dpdk.org/patch/49477/
> > > 
> > > Debian folks are building like this for the _generic_ image.
> > > What ever works for every distros, I am fine with that.
> > > 
> > > meson configure -Dmachine=default
> > > meson build
> > > cd build
> > > ninja
> > > ninja install
> > 
> > I think we agree on the idea of having different configs
> > for unmodified A72 core and generic build working for all.
> 
> Yes, I agree. config or some scheme to address the generic and
> default
> usecase.
> 
> > The remaining bits to discuss are:
> > 	- do we want to use the armv8 config for unmodified A72?
> > 	- what should be the name of the generic config?
> 
> If all distros following "meson configure -Dmachine=default" scheme
> why not follow that to make generic image. i.e when machine=default
> set then Cache lize size 128B CL specific stuff be kicked in else
> it probe the value based on MIDR from sysfs.
> 
> 
> > When digging more the config files in meson, I found this:
> > 	
> > http://mesonbuild.com/Cross-compilation.html#cross-file-locations
> > It says that distros or compilers should provide some config files.
> > It means we should check if some standard names are emerging
> > and try to follow the same naming, or even re-use existing config
> > files.
> 
> I think this for cross compilation. if I understand it correctly,
> distro folks build arm64 image on arm64 target(not on x86) with
> generic
> images with lowest denominator cpu flags and such that works for all
> platforms.
> 
> Something similar found in arch linux website for arm64.
> https://archlinuxarm.org/platforms/armv8/generic
> 
> See Platforms: ARMv8
> 
> Anyway I am leaving this decision to distro folks or whoever is
> expert
> in meson based distro build generic creation.

Just a comment to confirm that yes, in general distributions do not do
cross-builds, but native builds. That is certainly the case for Debian,
and I am 99% sure it is also the case for Ubuntu and SUSE.

-- 
Kind regards,
Luca Boccassi