[dpdk-dev] [PATCH v8 01/14] build: alias default build as generic

[Bruce Richardson]

On Mon, Nov 09, 2020 at 12:12:48PM +0000, Juraj Linkeš wrote:
> 
> 
> > -----Original Message-----
> > From: Honnappa Nagarahalli <Honnappa.Nagarahalli at arm.com>
> > Sent: Saturday, November 7, 2020 12:53 AM
> > To: Juraj Linkeš <juraj.linkes at pantheon.tech>; bruce.richardson at intel.com;
> > Ruifeng Wang <Ruifeng.Wang at arm.com>; Phil Yang <Phil.Yang at arm.com>;
> > vcchunga at amazon.com; Dharmik Thakkar <Dharmik.Thakkar at arm.com>;
> > jerinjacobk at gmail.com; hemant.agrawal at nxp.com; Ajit Khaparde
> > (ajit.khaparde at broadcom.com) <ajit.khaparde at broadcom.com>;
> > ferruh.yigit at intel.com; aconole at redhat.com
> > Cc: dev at dpdk.org; nd <nd at arm.com>; Honnappa Nagarahalli
> > <Honnappa.Nagarahalli at arm.com>; nd <nd at arm.com>
> > Subject: RE: [PATCH v8 01/14] build: alias default build as generic
> > 
> > <snip>
> > 
> > >
> > > The current machine='default' build name is not descriptive. The
> > > actual default build is machine='native'. Add an alternative string
> > > which does the same build and better describes what we're building:
> > > machine='generic'. Leave machine='default' for backwards compatibility.
> > >
> > > Signed-off-by: Juraj Linkeš <juraj.linkes at pantheon.tech>
> > > ---
> > >  config/arm/meson.build                    | 5 +++--
> > >  config/meson.build                        | 9 +++++----
> > >  doc/guides/prog_guide/build-sdk-meson.rst | 4 ++--
> > >  meson_options.txt                         | 2 +-
> > >  4 files changed, 11 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/config/arm/meson.build b/config/arm/meson.build index
> > > 42b4e43c7..d4066ade8 100644
> > > --- a/config/arm/meson.build
> > > +++ b/config/arm/meson.build
> > > @@ -1,12 +1,13 @@
> > >  # SPDX-License-Identifier: BSD-3-Clause  # Copyright(c) 2017 Intel
> > > Corporation.
> > >  # Copyright(c) 2017 Cavium, Inc
> > > +# Copyright(c) 2020 PANTHEON.tech s.r.o.
> > >
> > >  # for checking defines we need to use the correct compiler flags
> > > march_opt =
> > > '-march=@0@'.format(machine)
> > >
> > >  arm_force_native_march = false
> > > -arm_force_default_march = (machine == 'default')
> > > +arm_force_generic_march = (machine == 'generic')
> > >
> > >  flags_common_default = [
> > >  	# Accelarate rte_memcpy. Be sure to run unit test
> > > (memcpy_perf_autotest) @@ -148,7 +149,7 @@ else
> > >  	cmd_generic = ['generic', '', '', 'default', '']
> > >  	cmd_output = cmd_generic # Set generic by default
> > >  	machine_args = [] # Clear previous machine args
> > > -	if arm_force_default_march and not meson.is_cross_build()
> > > +	if arm_force_generic_march and not meson.is_cross_build()
> > >  		machine = impl_generic
> > >  		impl_pn = 'default'
> > >  	elif not meson.is_cross_build()
> > > diff --git a/config/meson.build b/config/meson.build index
> > > 258b01d06..c7f7aa6e2 100644
> > > --- a/config/meson.build
> > > +++ b/config/meson.build
> > > @@ -68,13 +68,14 @@ else
> > >  	machine = get_option('machine')
> > >  endif
> > >
> > > -# machine type 'default' is special, it defaults to the per arch
> > > agreed common -# minimal baseline needed for DPDK.
> > > +# machine type 'generic' is special, it defaults to the per arch
> > > +agreed common # minimal baseline needed for DPDK. Machine type
> > > +'default' is also supported # with the same meaning for backwards
> > compatibility.
> > >  # 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 machine == 'default' or machine == 'generic'
> > >  	if host_machine.cpu_family().startswith('x86')
> > >  		# matches the old pre-meson build systems default
> > >  		machine = 'corei7'
> > > @@ -82,7 +83,7 @@ if machine == 'default'
> > >  		machine = 'armv7-a'
> > >  	elif host_machine.cpu_family().startswith('aarch')
> > >  		# arm64 manages defaults in config/arm/meson.build
> > > -		machine = 'default'
> > > +		machine = 'generic'
> > >  	elif host_machine.cpu_family().startswith('ppc')
> > >  		machine = 'power8'
> > >  	endif
> > > diff --git a/doc/guides/prog_guide/build-sdk-meson.rst
> > > b/doc/guides/prog_guide/build-sdk-meson.rst
> > > index 3429e2647..c7e12eedf 100644
> > > --- a/doc/guides/prog_guide/build-sdk-meson.rst
> > > +++ b/doc/guides/prog_guide/build-sdk-meson.rst
> > > @@ -85,7 +85,7 @@ Project-specific options are passed used -
> > > Doption=value::
> > >
> > >  	meson -Denable_docs=true fullbuild  # build and install docs
> > >
> > > -	meson -Dmachine=default  # use builder-independent baseline -
> > > march
> > > +	meson -Dmachine=generic  # use builder-independent baseline -
> > > march
> > >
> > >  	meson -Ddisable_drivers=event/*,net/tap  # disable tap driver and all
> > >  					# eventdev PMDs for a smaller build
> > @@ -114,7 +114,7 @@ Examples
> > > of setting some of the same options using meson configure::
> > >          re-scan from meson.
> > >
> > >  .. note::
> > > -        machine=default uses a config that works on all supported architectures
> > > +        machine=generic uses a config that works on all supported
> > > + architectures
> > >          regardless of the capabilities of the machine where the build
> > > is happening.
> > >
> > >  As well as those settings taken from ``meson configure``, other
> > > options diff -- git a/meson_options.txt b/meson_options.txt index
> > > 9bf18ab6b..ce23289e3
> > > 100644
> > > --- a/meson_options.txt
> > > +++ b/meson_options.txt
> > > @@ -23,7 +23,7 @@ option('kernel_dir', type: 'string', value: '',
> > > option('lib_musdk_dir', type: 'string', value: '',
> > >  	description: 'path to the MUSDK library installation directory')
> > > option('machine', type: 'string', value: 'native',
> > > -	description: 'set the target machine type')
> > > +	description: 'set the target machine type. Set to generic for a
> > > +build usable on most machines of the build machine architecture, set
> > > +to
> >                         ^^^^ all
> 
> I don't think we've settled this with Bruce. According to him, the build with "machine=generic" on x86 won't necessarily produce a build usable on all machines, so I went with most machines.
> 
It will produce a build that works on all supported machines, so I think
"all" is probably ok to use.

/Bruce