Re: [dpdk-dev] [PATCH v5] build: use platform option for generic and native

["Wang, Yinan" <yinan.wang@intel.com>]

Hi Linkeš，

This patch cause vhost/virtio basic pvp test with 1518 packet size performance drop about 9% on IA platform.

BR,
Yinan

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Juraj Linkeš
> Sent: 2021年4月21日 16:38
> To: Thomas Monjalon <thomas@monjalon.net>
> Cc: david.marchand@redhat.com; Richardson, Bruce
> <bruce.richardson@intel.com>; Honnappa.Nagarahalli@arm.com;
> Ruifeng.Wang@arm.com; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v5] build: use platform option for generic
> and native
> 
> 
> 
> > -----Original Message-----
> > From: Thomas Monjalon <thomas@monjalon.net>
> > Sent: Tuesday, April 20, 2021 10:36 AM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: david.marchand@redhat.com; bruce.richardson@intel.com;
> > Honnappa.Nagarahalli@arm.com; Ruifeng.Wang@arm.com;
> dev@dpdk.org
> > Subject: Re: [PATCH v5] build: use platform option for generic and native
> >
> > 20/04/2021 10:16, Juraj Linkeš:
> > > > option('platform', type: 'string', value: '',
> > > > -	description: 'use configuration for a particular platform (such as a
> SoC).')
> > > > +option('platform', type: 'string', value: 'generic',
> > > > +	description: 'Platform to build, either "native", "generic" or an
> > > > +Arm SoC. Please refer to the Linux build guide for more
> > > > +information.')
> > >
> > > The other thing we need to discuss is the fact that we're changing the
> behavior
> > in this patch from machine=native to platform=generic (and the implied
> > cpu_instruction_set=genetic which equals to machine=generic). We need
> more
> > feedback on this - Thomas, David? Should we include more people? The
> reason
> > for this change is we want the build without any meson options (specified
> on
> > cmdline) to be usable on as many different machines of the same
> architecture
> > (this is my understanding form the discussion with Bruce), which is the
> generic
> > platform. We could preserve the current behavior by setting the default
> to
> > native, so we just need more discussion.
> >
> > I don't understand why you need to change the behaviour.
> 
> Well, we don't *need* to change the behavior - I don't mind it either way.
> We've come to this point after discussing the change with Bruce. I believe
> Bruce mentioned the intention of the build without any meson cmdline
> options was to produce a build usable on most machines that match the
> build architecture and the generic build fits better (native build being more
> tailored to the build machine as opposed to the generic build).
> 
> I don't want to speak for Bruce though, so it'd be the best if he gave his
> thoughts on the matter.
> 
> > If we change the behaviour, it must be done carefully after a deprecation
> notice
> > and an agreement of the Technical Board.
> >
> >
> 
> Ok, one thing we could do is preserve the behavior in this patch and go
> through this process with a separate change.