Re: [dpdk-dev] [PATCH 2/2] build: establish an invariant machine type

[Luca Boccassi <bluca@debian.org>]

On Wed, 2018-11-14 at 12:34 +0100, Christian Ehrhardt wrote:
> Add the machine definition 'baseline' which is special compared
> to 'native' (most optimized for current system) or any explicit
> type (external entity has to decide on the type).
> 
> It defaults to the per arch agreed common minimal baseline
> needed for DPDK to reasonable work.
> 
> That might not be the most optimized, but the most portable
> version while still being able to support the CPU features
> required for DPDK.
> 
> Going forward this can be bumped up by the DPDK project, but it
> can never be an invariant like 'native'.
> 
> Distributions and other needing portable code are expected to
> define the machine as 'baseline'.
> 
> Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> ---
>  config/meson.build | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/config/meson.build b/config/meson.build
> index 1af305f46..23f612457 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -7,6 +7,27 @@ if meson.is_cross_build()
>  else
>  	machine = get_option('machine')
>  endif
> +
> +# machine type 'baseline' is special, it defaults to the per arch
> agreed common
> +# minimal baseline needed for DPDK.
> +# That might not be the most optimized, but the most portable
> version while
> +# still being able to support the CPU features required for DPDK.
> +# This can be bumped up by the DPDK project, but it can never be an
> +# invariant like 'native'
> +if machine == 'baseline'
> +	if host_machine.cpu_family().startswith('x86')
> +		# matches the old pre-meson build systems default
> +		machine = 'corei7'
> +	elif host_machine.cpu_family().startswith('arm')
> +		machine = 'armv7a'

gcc complains, it wants armv7-a instead (tried on a native armhf
machine, with the change the meson configure passes and ninja is now
_slowly_ building its way through)

> +	elif host_machine.cpu_family().startswith('aarch')
> +		# arm64 manages defaults in config/arm/meson.build
> +		machine = 'default'
> +	elif host_machine.cpu_family().startswith('ppc')
> +		machine = 'power8'
> +	endif
> +endif
> +
>  dpdk_conf.set('RTE_MACHINE', machine)
>  machine_args = []
>  

-- 
Kind regards,
Luca Boccassi