On Tue 22-10-19 10:47:58, Johannes Weiner wrote: > inactive_list_is_low() should be about one thing: checking the ratio > between inactive and active list. Kitchensink checks like the one for > swap space makes the function hard to use and modify its > callsites. Luckly, most callers already have an understanding of the > swap situation, so it's easy to clean up. > > get_scan_count() has its own, memcg-aware swap check, and doesn't even > get to the inactive_list_is_low() check on the anon list when there is > no swap space available. > > shrink_list() is called on the results of get_scan_count(), so that > check is redundant too. > > age_active_anon() has its own totalswap_pages check right before it > checks the list proportions. > > The shrink_node_memcg() site is the only one that doesn't do its own > swap check. Add it there. > > Then delete the swap check from inactive_list_is_low(). > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> OK, makes sense to me. Acked-by: Michal Hocko <mhocko@xxxxxxxx> > --- > mm/vmscan.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index be3c22c274c1..622b77488144 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2226,13 +2226,6 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file, > unsigned long refaults; > unsigned long gb; > > - /* > - * If we don't have swap space, anonymous page deactivation > - * is pointless. > - */ > - if (!file && !total_swap_pages) > - return false; > - > inactive = lruvec_lru_size(lruvec, inactive_lru, sc->reclaim_idx); > active = lruvec_lru_size(lruvec, active_lru, sc->reclaim_idx); > > @@ -2653,7 +2646,7 @@ static void shrink_node_memcg(struct pglist_data *pgdat, struct mem_cgroup *memc > * Even if we did not try to evict anon pages at all, we want to > * rebalance the anon lru active/inactive ratio. > */ > - if (inactive_list_is_low(lruvec, false, sc, true)) > + if (total_swap_pages && inactive_list_is_low(lruvec, false, sc, true)) > shrink_active_list(SWAP_CLUSTER_MAX, lruvec, > sc, LRU_ACTIVE_ANON); > } > -- > 2.23.0 -- Michal Hocko SUSE Labs
