Thanks Michal, I will add your comments. Pasha On Thu, Sep 3, 2020 at 3:07 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > 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
