Messages in this thread | | | Date | Wed, 30 Mar 2016 11:24:38 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH] mm/highmem: simplify is_highmem() |
| |
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.min@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
| |