Re: [PATCH 18/22] mm: mark DEVICE_PUBLIC as broken

Jason Gunthorpe
2019-06-13T19:44:37Z

On Thu, Jun 13, 2019 at 11:43:21AM +0200, Christoph Hellwig wrote:
> The code hasn't been used since it was added to the tree, and doesn't
> appear to actually be usable. Mark it as BROKEN until either a user
> comes along or we finally give up on it.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> mm/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 0d2ba7e1f43e..406fa45e9ecc 100644
> +++ b/mm/Kconfig
> @@ -721,6 +721,7 @@ config DEVICE_PRIVATE
> config DEVICE_PUBLIC
> bool "Addressable device memory (like GPU memory)"
> depends on ARCH_HAS_HMM
> + depends on BROKEN
> select HMM
> select DEV_PAGEMAP_OPS

This seems a bit harsh, we do have another kconfig that selects this
one today:

config DRM_NOUVEAU_SVM
bool "(EXPERIMENTAL) Enable SVM (Shared Virtual Memory) support"
depends on ARCH_HAS_HMM
depends on DRM_NOUVEAU
depends on STAGING
select HMM_MIRROR
select DEVICE_PRIVATE
default n
help
Say Y here if you want to enable experimental support for
Shared Virtual Memory (SVM).

Maybe it should be depends on STAGING not broken?

or maybe nouveau_svm doesn't actually need DEVICE_PRIVATE?

Jason