On Fri, Jul 27, 2018 at 03:17:27PM -0600, Jane Chu wrote: > +++ b/include/linux/mm.h > @@ -387,6 +387,13 @@ enum page_entry_size { > * These are the virtual MM functions - opening of an area, closing and > * unmapping it (needed to keep files on disk up-to-date etc), pointer > * to the functions called when a no-page or a wp-page exception occurs. > + * > + * Note, when a new function is introduced to vm_operations_struct and > + * added to hugetlb_vm_ops, please consider adding the function to > + * shm_vm_ops. This is because under System V memory model, though > + * mappings created via shmget/shmat with "huge page" specified are > + * backed by hugetlbfs files, their original vm_ops are overwritten with > + * shm_vm_ops. > */ > struct vm_operations_struct { I don't think this header file is the right place for this comment. I'd think a better place for it would be at the definition of hugetlb_vm_ops.