On Wed 14-12-22 10:57:52, Huang, Ying wrote: > Michal Hocko <mhocko@xxxxxxxx> writes: [...] > > This makes sense but I suspect that this wasn't intended also for > > memcg triggered reclaim. This would mean that a memory pressure in one > > hierarchy could trigger paging out pages of a different hierarchy if the > > demotion target is close to full. > > It seems that it's unnecessary to wake up kswapd of demotion target node > in most cases. Because we will try to reclaim on the demotion target > nodes in the loop of do_try_to_free_pages(). It may be better to loop > the zonelist in the reverse order. Because the demotion targets are > usually located at the latter of the zonelist. Reclaiming from demotion targets first would deal with that as well. Thanks! Let's establish whether this is something we really need/want fix first. -- Michal Hocko SUSE Labs
