RE: [EXT] [PATCH 1/2] config/arm: update config for Neoverse N2

[Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>]

> -----Original Message-----
> From: Ruifeng Wang <Ruifeng.Wang@arm.com>
> Sent: Thursday, June 8, 2023 9:59 AM
> To: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>;
> bruce.richardson@intel.com
> Cc: dev@dpdk.org; Jerin Jacob Kollanukkaran <jerinj@marvell.com>;
> Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>; Feifei Wang
> <Feifei.Wang2@arm.com>; nd <nd@arm.com>; nd <nd@arm.com>
> Subject: RE: [EXT] [PATCH 1/2] config/arm: update config for Neoverse N2
> 
> > -----Original Message-----
> > From: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>
> > Sent: Wednesday, June 7, 2023 11:12 PM
> > To: Ruifeng Wang <Ruifeng.Wang@arm.com>; bruce.richardson@intel.com
> > Cc: dev@dpdk.org; jerinj@marvell.com; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>;
> > Feifei Wang <Feifei.Wang2@arm.com>; nd <nd@arm.com>
> > Subject: RE: [EXT] [PATCH 1/2] config/arm: update config for Neoverse N2
> >
> > > Updated maximum number of lcores and numa nodes to support
> platforms
> > > with multiple numa nodes.
> > > Added mcpu compiler option.
> > >
> > > Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > > Reviewed-by: Feifei Wang <feifei.wang2@arm.com>
> > > ---
> > >  config/arm/meson.build | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/config/arm/meson.build b/config/arm/meson.build index
> > > 5213434ca4..9e55e9f2a4 100644
> > > --- a/config/arm/meson.build
> > > +++ b/config/arm/meson.build
> > > @@ -91,11 +91,12 @@ part_number_config_arm = {
> > >      '0xd49': {
> > >          'march': 'armv8.5-a',
> > >          'march_features': ['sve2'],
> > > +	'compiler_options':  ['-mcpu=neoverse-n2'],
> >
> > Hi Ruifeng,
> 
> Hi Pavan,
> 
> > I see the following warning when compiling with GCC 12
> >
> > cc1: warning: switch '-mcpu=neoverse-n2' conflicts with '-march=armv8.5-
> a+sve2+crypto'
> > switch
> >
> > Removing 'armv8.5-a' from the list makes the warning go away but what's
> the correct march
> > for neoverse-n2?
> > Armv9.0-a is not a supported march flag in GCC.
> 
> Thanks for pointing this out.
> Neoverse-n2 is v9.0-a. The corresponding march flag in GCC is 'armv9-a' [1].
> 'armv8.5-a' should be removed from the list. It was used when armv9-
> a/neoverse-n2 is not available in compilers.

I see, should I send a fix? 

> 
> [1] https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__gcc.gnu.org_onlinedocs_gcc-2D12.3.0_gcc_AArch64-
> 2DOptions.html&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=E3SgYMjtKCM
> VsB-fmvgGV3o-
> g_fjLhk5Pupi9ijohpc&m=v0RqCjWj9zEynw7pgt6ghZX4BNI5Vnk0UxA4sYAxRr
> RtO8lLHUhKYCNTniy2Jb5L&s=tEj1y2WPKFeatDFYUFqX49tv-
> 2rG2wx0UiWklOYUvhY&e=
> 
> >
> > >          'flags': [
> > >              ['RTE_MACHINE', '"neoverse-n2"'],
> > >              ['RTE_ARM_FEATURE_ATOMICS', true],
> > > -            ['RTE_MAX_LCORE', 64],
> > > -            ['RTE_MAX_NUMA_NODES', 1]
> > > +            ['RTE_MAX_LCORE', 128],
> > > +            ['RTE_MAX_NUMA_NODES', 2]
> > >          ]
> > >      }
> > >  }
> > > --
> > > 2.25.1