On Wed 14-08-19 17:41:07, David Hildenbrand wrote:
> online_pages always corresponds to nr_pages. Simplify the code, getting
> rid of online_pages_blocks(). Add some comments.
>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks!
> ---
> mm/memory_hotplug.c | 36 ++++++++++++++++--------------------
> 1 file changed, 16 insertions(+), 20 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 10ad970f3f14..63b1775f7cf8 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -632,31 +632,27 @@ static void generic_online_page(struct page *page, unsigned int order)
> #endif
> }
>
> -static int online_pages_blocks(unsigned long start, unsigned long nr_pages)
> -{
> - unsigned long end = start + nr_pages;
> - int order, onlined_pages = 0;
> -
> - while (start < end) {
> - order = min(MAX_ORDER - 1,
> - get_order(PFN_PHYS(end) - PFN_PHYS(start)));
> - (*online_page_callback)(pfn_to_page(start), order);
> -
> - onlined_pages += (1UL << order);
> - start += (1UL << order);
> - }
> - return onlined_pages;
> -}
> -
> static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
> void *arg)
> {
> - unsigned long onlined_pages = *(unsigned long *)arg;
> + const unsigned long end_pfn = start_pfn + nr_pages;
> + unsigned long pfn;
> + int order;
> +
> + /*
> + * Online the pages. The callback might decide to keep some pages
> + * PG_reserved (to add them to the buddy later), but we still account
> + * them as being online/belonging to this zone ("present").
> + */
> + for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) {
> + order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn)));
> + (*online_page_callback)(pfn_to_page(pfn), order);
> + }
>
> - onlined_pages += online_pages_blocks(start_pfn, nr_pages);
> - online_mem_sections(start_pfn, start_pfn + nr_pages);
> + /* mark all involved sections as online */
> + online_mem_sections(start_pfn, end_pfn);
>
> - *(unsigned long *)arg = onlined_pages;
> + *(unsigned long *)arg += nr_pages;
> return 0;
> }
>
> --
> 2.21.0
>
--
Michal Hocko
SUSE Labs
