On Wed 30-03-16 13:43:42, Chanho Min wrote:
> The is_highmem() is can be simplified by use of is_highmem_idx().
> This patch removes redundant code and will make it easier to maintain
> if the zone policy is changed or a new zone is added.
>
> Signed-off-by: Chanho Min <chanho....@lge.com>
> ---
> include/linux/mmzone.h | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index e23a9e7..9ac90c3 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -817,10 +817,7 @@ static inline int is_highmem_idx(enum zone_type idx)
> static inline int is_highmem(struct zone *zone)
> {
> #ifdef CONFIG_HIGHMEM
> - int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
> - return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
> - (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
> - zone_movable_is_highmem());
> + return is_highmem_idx(zone_idx(zone));
This will reintroduce the pointer arithmetic removed by ddc81ed2c5d4
("remove sparse warning for mmzone.h") AFAICS. I have no idea how much
that matters though. The mentioned commit doesn't tell much about saves
except for
"
On X86_32 this saves a sar, but code size increases by one byte per
is_highmem() use due to 32-bit cmps rather than 16 bit cmps.
"
> #else
> return 0;
> #endif
> --
> 1.7.9.5
>
--
Michal Hocko
SUSE Labs
