On Thu, Oct 08, 2020 at 01:42:00PM +0200, Vlastimil Babka wrote: > Currently, pcplists are drained during set_migratetype_isolate() which means > once per pageblock processed start_isolate_page_range(). This is somewhat > wasteful. Moreover, the callers might need different guarantees, and the > draining is currently prone to races and does not guarantee that no page > from isolated pageblock will end up on the pcplist after the drain. > > Better guarantees are added by later patches and require explicit actions > by page isolation users that need them. Thus it makes sense to move the > current imperfect draining to the callers also as a preparation step. > > Suggested-by: David Hildenbrand <david@xxxxxxxxxx> > Suggested-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> > Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> > Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> > Acked-by: Michal Hocko <mhocko@xxxxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> -- Oscar Salvador SUSE L3
