Re: [dpdk-dev] [EXT] Re: [PATCH v2 2/4] meson: change default cache line size for armv8

[Hemant Agrawal <hemant.agrawal@nxp.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Honnappa Nagarahalli
> Sent: Thursday, April 18, 2019 10:31 AM
> To: yskoh@mellanox.com; bruce.richardson@intel.com; jerinj@marvell.com;
> pbhagavatula@marvell.com; shahafs@mellanox.com
> Cc: dev@dpdk.org; thomas@monjalon.net; Gavin Hu (Arm Technology
> China) <Gavin.Hu@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; nd <nd@arm.com>; nd <nd@arm.com>
> Subject: [EXT] Re: [dpdk-dev] [PATCH v2 2/4] meson: change default cache
> line size for armv8
> 
 
> >
> > Currently, the cache line size of armv8 CPUs having Implementor ID of
> > 0x41 is
> > 64 bytes.
> I guess you meant to say 128 bytes


"the current default is 128, changing it to 64."
 
> 
> >
> > Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
> > ---
> >
> > v2:
> > * introduce flags_arm replacing flags_generic instead of using the
> > extra flags
> >
> >  config/arm/meson.build | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/config/arm/meson.build b/config/arm/meson.build index
> > 22a062bad9..1db4ad2ee7 100644
> > --- a/config/arm/meson.build
> > +++ b/config/arm/meson.build
> > @@ -32,6 +32,11 @@ flags_generic = [
> >       ['RTE_MAX_LCORE', 256],
> >       ['RTE_USE_C11_MEM_MODEL', true],
> >       ['RTE_CACHE_LINE_SIZE', 128]]
> > +flags_arm = [
> > +     ['RTE_MACHINE', '"armv8a"'],
> > +     ['RTE_MAX_LCORE', 256],
> I am not aware of any implementations with implementor ID 0x41. Bluefield
> is the first one I am aware of. May be we can keep this smaller, 16?

NXP also support implementer as 0x41, 16 will be good. 

> 
> > +     ['RTE_USE_C11_MEM_MODEL', true],
> > +     ['RTE_CACHE_LINE_SIZE', 64]]
> >  flags_cavium = [
> >       ['RTE_CACHE_LINE_SIZE', 128],
> >       ['RTE_MAX_NUMA_NODES', 2],
> > @@ -88,7 +93,7 @@ machine_args_cavium = [
> >
> >  ## Arm implementer ID (ARM DDI 0487C.a, Section G7.2.106, Page
> > G7-5321) impl_generic = ['Generic armv8', flags_generic,
> > machine_args_generic]
> > -impl_0x41 = ['Arm', flags_generic, machine_args_generic]
> > +impl_0x41 = ['Arm', flags_arm, machine_args_generic]
> >  impl_0x42 = ['Broadcom', flags_generic, machine_args_generic]
> >  impl_0x43 = ['Cavium', flags_cavium, machine_args_cavium]
> >  impl_0x44 = ['DEC', flags_generic, machine_args_generic]
> > --
> > 2.11.0