Infinite looping observed in __offline_pages

[Michal Hocko]

On Wed 22-08-18 11:58:02, Mike Kravetz wrote:
> On 08/22/2018 02:30 AM, Aneesh Kumar K.V wrote:
[...]
> > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> > index 4eb6e824a80c..f9bdea685cf4 100644
> > --- a/mm/memory_hotplug.c
> > +++ b/mm/memory_hotplug.c
> > @@ -1338,7 +1338,8 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
> >  				return pfn;
> >  			if (__PageMovable(page))
> >  				return pfn;
> > -			if (PageHuge(page)) {
> > +			if (IS_ENABLED(CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION) &&
> > +			    PageHuge(page)) {
> 
> How about using hugepage_migration_supported instead?  It would automatically
> catch those non-migratable huge page sizes.  Something like:
> 
> 			if (PageHuge(page) &&
> 			    hugepage_migration_supported(page_hstate(page))) {

Ohh, definitely, this is much better.
-- 
Michal Hocko
SUSE Labs