On Tue 01-09-20 08:46:15, Pavel Tatashin wrote: [...] > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index e9d5ab5d3ca0..d6d54922bfce 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1575,6 +1575,15 @@ static int __ref __offline_pages(unsigned long start_pfn, > /* check again */ > ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, > NULL, check_pages_isolated_cb); > + /* > + * per-cpu pages are drained in start_isolate_page_range, but if > + * there are still pages that are not free, make sure that we > + * drain again, because when we isolated range we might > + * have raced with another thread that was adding pages to > + * pcp list. I would also add * Forward progress should be still guaranteed because * pages on the pcp list can only belong to MOVABLE_ZONE * because has_unmovable_pages explicitly checks for * PageBuddy on freed pages on other zones. > + */ > + if (ret) > + drain_all_pages(zone); > } while (ret); > > /* Ok, all of our target is isolated. > -- > 2.25.1 > -- Michal Hocko SUSE Labs
