On Mon 27-05-19 13:11:44, David Hildenbrand wrote:
> Will come in handy when wanting to handle errors after
> arch_add_memory().
I do not understand this. Why do you add a code for something that is
not possible on this HW (based on the comment - is it still valid btw?)
> Cc: Martin Schwidefsky <schwidef...@de.ibm.com>
> Cc: Heiko Carstens <heiko.carst...@de.ibm.com>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: Michal Hocko <mho...@suse.com>
> Cc: Mike Rapoport <r...@linux.vnet.ibm.com>
> Cc: David Hildenbrand <da...@redhat.com>
> Cc: Vasily Gorbik <g...@linux.ibm.com>
> Cc: Oscar Salvador <osalva...@suse.com>
> Signed-off-by: David Hildenbrand <da...@redhat.com>
> ---
> arch/s390/mm/init.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index d552e330fbcc..14955e0a9fcf 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -243,12 +243,13 @@ int arch_add_memory(int nid, u64 start, u64 size,
> void arch_remove_memory(int nid, u64 start, u64 size,
> struct vmem_altmap *altmap)
> {
> - /*
> - * There is no hardware or firmware interface which could trigger a
> - * hot memory remove on s390. So there is nothing that needs to be
> - * implemented.
> - */
> - BUG();
> + unsigned long start_pfn = start >> PAGE_SHIFT;
> + unsigned long nr_pages = size >> PAGE_SHIFT;
> + struct zone *zone;
> +
> + zone = page_zone(pfn_to_page(start_pfn));
> + __remove_pages(zone, start_pfn, nr_pages, altmap);
> + vmem_remove_mapping(start, size);
> }
> #endif
> #endif /* CONFIG_MEMORY_HOTPLUG */
> --
> 2.20.1
>
--
Michal Hocko
SUSE Labs
