Re: [PATCH] mm/hmm: kconfig split HMM address space mirroring from device memory

[Jerome Glisse]

On Wed, Apr 17, 2019 at 12:33:35PM -0700, Guenter Roeck wrote:
> On Wed, Apr 17, 2019 at 02:26:18PM -0400, Jerome Glisse wrote:
> > On Wed, Apr 17, 2019 at 11:21:18AM -0700, Guenter Roeck wrote:
> > > On Thu, Apr 11, 2019 at 02:03:26PM -0400, jglisse@xxxxxxxxxx wrote:
> > > > From: Jérôme Glisse <jglisse@xxxxxxxxxx>
> > > > 
> > > > To allow building device driver that only care about address space
> > > > mirroring (like RDMA ODP) on platform that do not have all the pre-
> > > > requisite for HMM device memory (like ZONE_DEVICE on ARM) split the
> > > > HMM_MIRROR option dependency from the HMM_DEVICE dependency.
> > > > 
> > > > Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx>
> > > > Cc: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> > > > Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> > > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > > > Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
> > > > Cc: John Hubbard <jhubbard@xxxxxxxxxx>
> > > > Tested-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> > > 
> > > In case it hasn't been reported already:
> > > 
> > > mm/hmm.c: In function 'hmm_vma_handle_pmd':
> > > mm/hmm.c:537:8: error: implicit declaration of function 'pmd_pfn'; did you mean 'pte_pfn'?
> > 
> > No it is pmd_pfn
> > 
> FWIW, this is a compiler message.
> 
> > > 
> > > and similar errors when building alpha:allmodconfig (and maybe others).
> > 
> > Does HMM_MIRROR get enabled in your config ? It should not
> > does adding depends on (X86_64 || PPC64) to ARCH_HAS_HMM
> > fix it ? I should just add that there for arch i do build.
> > 
> 
> The eror is seen with is alpha:allmodconfig. "make ARCH=alpha allmodconfig".
> It does set CONFIG_ARCH_HAS_HMM=y.
> 
> This patch has additional problems. For arm64:allmodconfig
> and many others, when running "make ARCH=arm64 allmodconfig":
> 
> WARNING: unmet direct dependencies detected for DEVICE_PRIVATE
>   Depends on [n]: ARCH_HAS_HMM_DEVICE [=n] && ZONE_DEVICE [=n]
>   Selected by [m]:
>   - DRM_NOUVEAU_SVM [=y] && HAS_IOMEM [=y] && ARCH_HAS_HMM [=y] && DRM_NOUVEAU [=m] && STAGING [=y]
> 
> WARNING: unmet direct dependencies detected for DEVICE_PRIVATE
>   Depends on [n]: ARCH_HAS_HMM_DEVICE [=n] && ZONE_DEVICE [=n]
>   Selected by [m]:
>   - DRM_NOUVEAU_SVM [=y] && HAS_IOMEM [=y] && ARCH_HAS_HMM [=y] && DRM_NOUVEAU [=m] && STAGING [=y]
> 
> WARNING: unmet direct dependencies detected for DEVICE_PRIVATE
>   Depends on [n]: ARCH_HAS_HMM_DEVICE [=n] && ZONE_DEVICE [=n]
>   Selected by [m]:
>   - DRM_NOUVEAU_SVM [=y] && HAS_IOMEM [=y] && ARCH_HAS_HMM [=y] && DRM_NOUVEAU [=m] && STAGING [=y]
> 
> This in turn results in:
> 
> arch64-linux-ld: mm/memory.o: in function `do_swap_page':
> memory.c:(.text+0x798c): undefined reference to `device_private_entry_fault'
> 
> not only on arm64, but on other architectures as well.
> 
> All those problems are gone after reverting this patch.
> 
> Guenter

Andrew let drop this patch i need to fix nouveau Kconfig first.

Cheers,
Jérôme