Re: [PATCH] mm: take memory hotplug lock within numa_zonelist_order_handler()

[Heiko Carstens]

On Wed, Jul 26, 2017 at 01:31:12PM +0200, Michal Hocko wrote:
> On Wed 26-07-17 13:17:38, Heiko Carstens wrote:
> [...]
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index 6d30e914afb6..fc32aa81f359 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -4891,9 +4891,11 @@ int numa_zonelist_order_handler(struct ctl_table *table, int write,
> >  				NUMA_ZONELIST_ORDER_LEN);
> >  			user_zonelist_order = oldval;
> >  		} else if (oldval != user_zonelist_order) {
> > +			mem_hotplug_begin();
> >  			mutex_lock(&zonelists_mutex);
> >  			build_all_zonelists(NULL, NULL);
> >  			mutex_unlock(&zonelists_mutex);
> > +			mem_hotplug_done();
> >  		}
> >  	}
> >  out:
> 
> Please note that this code has been removed by
> http://lkml.kernel.org/r/20170721143915.14161-2-mhocko@xxxxxxxxxxx It
> will get to linux-next as soon as Andrew releases a new version mmotm
> tree.

We still would need something for 4.13, no?