At 2020-06-30 04:24:29, "Mike Rapoport" <rppt@kernel.org> wrote:
>On Mon, Jun 29, 2020 at 11:50:15AM -0700, David Rientjes wrote:
>> On Tue, 30 Jun 2020, Su Hui wrote:
>> 
>> > remove the redundancy code, the zone_start_pfn
>> > is assigned from zone->zone_start_pfn
>> > Signed-off-by: Su Hui <sh_def@163.com>
>> 
>> I don't think this is redundant, it's used by memory hotplug when onlining 
>> new memory.
>
>Right, it is:
>
>$ git grep -wn init_currently_empty_zone mm/memory_hotplug.c
>mm/memory_hotplug.c:697:            init_currently_empty_zone(zone, start_pfn, nr_pages);
>
>
>> > ---
>> >  mm/page_alloc.c | 2 --
>> >  1 file changed, 2 deletions(-)
>> > 
>> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> > index 3c4eb750a199..3372a8c9fbc4 100644
>> > --- a/mm/page_alloc.c
>> > +++ b/mm/page_alloc.c
>> > @@ -6215,8 +6215,6 @@ void __meminit init_currently_empty_zone(struct zone *zone,
>> >  	if (zone_idx > pgdat->nr_zones)
>> >  		pgdat->nr_zones = zone_idx;
>> >  
>> > -	zone->zone_start_pfn = zone_start_pfn;
>> > -
>> >  	mminit_dprintk(MMINIT_TRACE, "memmap_init",
>> >  			"Initialising map node %d zone %lu pfns %lu -> %lu\n",
>> >  			pgdat->node_id,
>> 
>
>-- 
>Sincerely yours,
>Mike.