Re: [dpdk-dev] [PATCH v3] build: establish an invariant machine type

[Christian Ehrhardt <christian.ehrhardt@canonical.com>]

On Wed, Nov 14, 2018 at 3:33 PM Christian Ehrhardt
<christian.ehrhardt@canonical.com> wrote:
>
> Add the machine definition 'default' 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 'default'.
>
> Changes in v2:
> - fixed the non 64 bit arm default type
> - changed baseline to default to match the old build system
>
> Changes in v3:
> - add acked-by's
> - removed old wording from commit message
> - adding Fixes line per request by Luca Boccassi

FYI: I'll drop the version update from the commit (I didn't have a
cover letter to add them instead).
Also I'll add the Acked-by of Luca to the other patch as well and move
the Fixes line as it was meant for the 1/2 of these.

Overall I think v4 will then be fine, all acks in place and hopefully
making it in before -rc4 is defined to fix more peoples builds.
Replying to this mail with both updated patches soon, let me know if
anything else is holding these back from being accepted.

> Fixes: 54d609a13876 ("build: add ppc64 meson build")
>
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
> Acked-by: Luca Boccassi <bluca@debian.org>
> 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..db32499b3 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 'default' 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 == 'default'
> +       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 = 'armv7-a'
> +       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 = []
>
> --
> 2.17.1
>


-- 
Christian Ehrhardt
Software Engineer, Ubuntu Server
Canonical Ltd