> On Sat, 2019-01-05 at 22:47 +0000, Honnappa Nagarahalli wrote: > > > On Fri, 2019-01-04 at 19:59 +0000, Yongseok Koh wrote: > > > > --------------------------------------------------------------- > > > > ---- > > > > --- > > > > 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.
> > Target specific configuration can be used for optimized target specific > configuration. > > Or any other ideas for distro config. > > > > > > > I can add config/defconfig_arm64-bluefield-linuxapp-gcc for legacy > > > > build anyway. > > > > > > > > > > Makes sense. > > > > > > > For the meson build, I know it parses the Main ID register to > > > > figure > > > > out Implementor ID and Part Number. However, Mellanox doesn't > > > > program > > > > our own ID yet but we set the Part Number as 0xd08 (A72). > > > > According to my folks, ARM's A53, A57, A72, and A73 designs all > > > > have > > > > 64B CL. If that's true, can I push a patch to make the change? > > > > > > Yes. Broadcom Stingray has the same situation i.e Use > > > flags_generic, > > > machine_args_generic > > > > > This will solve only the native compilation issue. It will not > > address distro compilation (may be this is not your goal?). > > See above. > > > > > > > Please comment. > > > > > > > > > > > > Thanks, > > > > Yongseok > > > >
