Re: [PATCH v2 5/8] mm/memory_hotplug: Drop MHP_MEMBLOCK_API

[Dan Williams]

On Tue, May 7, 2019 at 11:38 AM David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> No longer needed, the callers of arch_add_memory() can handle this
> manually.
>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxxx>
> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
> Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> Cc: Qian Cai <cai@xxxxxx>
> Cc: Arun KS <arunks@xxxxxxxxxxxxxx>
> Cc: Mathieu Malaterre <malat@xxxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
>  include/linux/memory_hotplug.h | 8 --------
>  mm/memory_hotplug.c            | 9 +++------
>  2 files changed, 3 insertions(+), 14 deletions(-)
>
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 2d4de313926d..2f1f87e13baa 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -128,14 +128,6 @@ extern void arch_remove_memory(int nid, u64 start, u64 size,
>  extern void __remove_pages(struct zone *zone, unsigned long start_pfn,
>                            unsigned long nr_pages, struct vmem_altmap *altmap);
>
> -/*
> - * Do we want sysfs memblock files created. This will allow userspace to online
> - * and offline memory explicitly. Lack of this bit means that the caller has to
> - * call move_pfn_range_to_zone to finish the initialization.
> - */
> -
> -#define MHP_MEMBLOCK_API               (1<<0)
> -
>  /* reasonably generic interface to expand the physical pages */
>  extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
>                        struct mhp_restrictions *restrictions);
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index e1637c8a0723..107f72952347 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -250,7 +250,7 @@ void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
>  #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
>
>  static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
> -               struct vmem_altmap *altmap, bool want_memblock)
> +                                  struct vmem_altmap *altmap)
>  {
>         int ret;
>
> @@ -293,8 +293,7 @@ int __ref __add_pages(int nid, unsigned long phys_start_pfn,
>         }
>
>         for (i = start_sec; i <= end_sec; i++) {
> -               err = __add_section(nid, section_nr_to_pfn(i), altmap,
> -                               restrictions->flags & MHP_MEMBLOCK_API);
> +               err = __add_section(nid, section_nr_to_pfn(i), altmap);
>
>                 /*
>                  * EEXIST is finally dealt with by ioresource collision
> @@ -1066,9 +1065,7 @@ static int online_memory_block(struct memory_block *mem, void *arg)
>   */
>  int __ref add_memory_resource(int nid, struct resource *res)
>  {
> -       struct mhp_restrictions restrictions = {
> -               .flags = MHP_MEMBLOCK_API,
> -       };
> +       struct mhp_restrictions restrictions = {};

With mhp_restrictions.flags no longer needed, can we drop
mhp_restrictions and just go back to a plain @altmap argument?