Re: [PATCH 2/2] mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long

From: Michal Hocko
Date: Mon Sep 18 2017 - 02:37:18 EST


On Fri 15-09-17 22:53:49, YASUAKI ISHIMATSU wrote:
> find_{smallest|biggest}_section_pfn()s find the smallest/biggest section
> and return the pfn of the section. But the functions are defined as int.
> So the functions always return 0x00000000 - 0xffffffff. It means
> if memory address is over 16TB, the functions does not work correctly.
>
> To handle 64 bit value, the patch defines find_{smallest|biggest}_section_pfn()
> as unsigned long.
>

Fixes: 815121d2b5cd ("memory_hotplug: clear zone when removing the memory")
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
> mm/memory_hotplug.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 38c3c37..120e45b 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -582,7 +582,7 @@ int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
>
> #ifdef CONFIG_MEMORY_HOTREMOVE
> /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
> -static int find_smallest_section_pfn(int nid, struct zone *zone,
> +static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
> unsigned long start_pfn,
> unsigned long end_pfn)
> {
> @@ -607,7 +607,7 @@ static int find_smallest_section_pfn(int nid, struct zone *zone,
> }
>
> /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
> -static int find_biggest_section_pfn(int nid, struct zone *zone,
> +static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
> unsigned long start_pfn,
> unsigned long end_pfn)
> {
> --
> 1.8.3.1

--
Michal Hocko
SUSE Labs