> -----Original Message-----
> From: Thomas Monjalon <tho...@monjalon.net>
> Sent: Thursday, July 8, 2021 3:33 PM
> To: Ruifeng Wang <ruifeng.w...@arm.com>; Jerin Jacob
> <jerinjac...@gmail.com>
> Cc: Bruce Richardson <bruce.richard...@intel.com>; Jan Viktorin
> <vikto...@rehivetech.com>; jer...@marvell.com; dev@dpdk.org;
> david.march...@redhat.com; nd <n...@arm.com>; Honnappa Nagarahalli
> <honnappa.nagaraha...@arm.com>
> Subject: Re: [dpdk-dev] [PATCH v4 3/3] build: add option to enable wait until
> equal
>
> 08/07/2021 08:32, Jerin Jacob:
> > On Thu, Jul 8, 2021 at 11:55 AM Ruifeng Wang <ruifeng.w...@arm.com>
> wrote:
> > > From: Jerin Jacob <jerinjac...@gmail.com>
> > > > On Wed, Jul 7, 2021 at 5:57 PM Bruce Richardson
> > > > <bruce.richard...@intel.com> wrote:
> > > > > On Wed, Jul 07, 2021 at 06:46:33AM +0000, Ruifeng Wang wrote:
> > > > > > From: Thomas Monjalon <tho...@monjalon.net>
> > > > > > > 07/07/2021 07:48, Ruifeng Wang:
> > > > > > > > Introduce a meson option 'use_wfe' to select wait until equal
> method.
> > > > > > > > The default is disable. Traditional polling loop is used.
> > > > > > > > When enabled, architecture specific mechanism is relied on
> > > > > > > > to do the wait.
> > > > > > >
> > > > > > > Why do we need an option?
> > > > > > > Can it be automatic to enable it when supported?
> > > > > > >
> > > > > > The problem is inconsistency in performance on different Arm
> platforms.
> > > > We had decided that each platform needs to enable it after some
> testing.
> > > > > >
> > > > > Can that not be done via variables in the cross-file for the
> > > > > builds, or via automatic detection if it's a native build? Is it
> > > > > likely that individual users of DPDK will be knowledgable enough
> > > > > to use this option
> > > > correctly?
> > > >
> > > > +1 to add this in cross-file instead of the top of config option
> > > > +as
> > > > scope if is only for arm64 builds.
> > >
> > > Currently this option is in config/arm/meson.build (flags_common).
> > > SoCs can build with this option enabled/disabled. And the ability is
> > > available for both native build and cross build as cross build also goes
> through meson.build.
> > > If a SoC needs to enable the option by default, an entry and be added to
> the SoC flags.
> > >
> > > The key difference here is whether this option need to be exposed to
> the top level config.
> >
> > In the view of limiting top-level config options and it is specific to
> > Arm, I think, it better to be a cross file only option.
>
> +1, sorry for the late notice.
> I would advocate to take this patch in 21.08-rc2.
>
If the decision is not to expose this option in top-level config, we can just
drop 3/3 patch.
Do I need to send a new version?
