On 2019-02-20 6:34 p.m., Jerome Glisse wrote: > On Wed, Feb 20, 2019 at 10:39:49PM +0000, Kuehling, Felix wrote: >> On 2019-02-20 5:12 p.m., Jerome Glisse wrote: >>> On Wed, Feb 20, 2019 at 07:18:17PM +0000, Kuehling, Felix wrote: >>>> [+Jerome] >>>> >>>> Why to we need ZONE_DEVICE. I didn't think this was needed for mirroring >>>> CPU page tables to device page tables. >>>> >>>> ARCH_HAS_HMM depends on (X86_64 || PPC64). Do we have some alternative >>>> for ARM support? >>>> >>>> Also, the name ARCH_HAS_HMM looks like it's meant to be selected by the >>>> CPU architecture rather than any driver. Jerome, do you have any advice? >>> This patch is wrong you need to depend on ARCH_HAS_HMM and >> Who selects ARCH_HAS_HMM? Currently I don't see this selected anywhere. >> So any config option that depends on it will be invisible in menuconfig. >> Do we need ARCH_HAS_HMM somewhere in the arch/x86/Kconfig and >> arch/powerpc/Kconfig? >> >> Also, ARCH_HAS_HMM does not currently support ARM. Does that mean we >> can't have ARM support in AMDGPU if we start using HMM? > ARCH_HAS_HMM is defined by architecture that support HMM. So par x86 > and PPC. It should not be hard to add it to ARM (i can not remember if > ARM has DAX yet or not, if ARM does not have DAX then you need to add > that first). Not having ARM support is a bummer. I just enabled KFD on ARM a few weeks ago. Now depending on HMM makes KFD unusable on ARM. [+Mark FYI] I hope this is only a temporary setback. >> Finally, ARCH_HAS_HMM has a bunch of dependencies. If they are not met, >> I guess it can't be enabled. Should those be "select"s instead? > No they should not be selected, people configuring their system need > to have the freedom of doing so. All those option are selected in all > the big distribution. As far as I can tell, the arch/x86/Kconfig doesn't select ARCH_HAS_HMM. Its default is "y", so it should be enabled on anything that meets the dependencies. But ZONE_DEVICE was not enabled by default. I think that's what broke our kernel configs. We'll fix our own kernel configs to enable ZONE_DEVICE and ARCH_HAS_HMM to get our internal builds to work again. I suspect other users with their own kernel configs will stumble over this and wonder why KFD and userptr support are disabled in their builds. Regards, Felix > >> config ARCH_HAS_HMM >> bool >> default y >> depends on (X86_64 || PPC64) >> depends on ZONE_DEVICE >> depends on MMU && 64BIT >> depends on MEMORY_HOTPLUG >> depends on MEMORY_HOTREMOVE >> depends on SPARSEMEM_VMEMMAP >> > Cheers, > Jérôme _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
