Re: [RFC PATCH v2 33/47] userfaultfd: add UFFD_FEATURE_MINOR_HUGETLBFS_HGM

[Peter Xu]

On Fri, Oct 21, 2022 at 04:36:49PM +0000, James Houghton wrote:
> Userspace must provide this new feature when it calls UFFDIO_API to
> enable HGM. Userspace can check if the feature exists in
> uffdio_api.features, and if it does not exist, the kernel does not
> support and therefore did not enable HGM.
> 
> Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx>

It's still slightly a pity that this can only be enabled by an uffd context
plus a minor fault, so generic hugetlb users cannot directly leverage this.

The patch itself looks good.

-- 
Peter Xu