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

Ralph Campbell
2019-06-13T19:53:02Z

On 6/13/19 12:44 PM, Jason Gunthorpe wrote:
> 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

I think you are confusing DEVICE_PRIVATE for DEVICE_PUBLIC.
DRM_NOUVEAU_SVM does use DEVICE_PRIVATE but not DEVICE_PUBLIC.