Re: [dpdk-dev] [EXT] Default cacheline size for ARM

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

> > > > > > Hi,
> > > > > >
> > > > > > The cacheline size (RTE_CACHE_LINE_SIZE) for ARM CPUs is set
> > > > > > to be 128B by default. Mellanox's BlueField is an ARM CPU
> > > > > > having
> > > > > > Cortex-A72
> > > > > > and its CL size is 64B.
> > > > Just wondering how many devices are out there with 128B cache
> > > > line? I also have not heard about any future devices with 128B
> > > > cache line. If the majority is 64B, why not keep 64B as the
> > > > default?
> > >
> > > The problem is, In the armv8 spec the cache line size is
> > > IMPLEMENTATION DEFINED. Marvell's embedded processors has 128B CL
> > > and Server processors has 64B CL.
> > >
> > > Assuming the defconfig_arm64-armv8a-linuxapp-gcc will be used by
> > > distro folks then that configuration should support all the devices
> > > with
> > > armv8.1 spec. For instance, marvells new chips are armv8.2 but we
> > > can not make that as default.
> > What will happen in the future when we will have v9, v10 etc? I think
> > the distro(generic/binary portable) config should get rid of v8.
> 
> Will it be too much overhead if the image is same for v8, v9 and v10.
> I think, we can inline with what distro folks are doing for other packages, I
> think, DPDK package does not need any exception.
Yes, we need to be inline with any other package. My understanding is that the image will be same for v8,v9,v10 (any input from distro engineers will help here). So, my question is, should the config file/name used by distros contain anything specific to armv8?