From: Johannes Weiner <hannes@xxxxxxxxxxx> Subject: mm: vmscan: move inactive_list_is_low() swap check to the caller 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(). Link: http://lkml.kernel.org/r/20191022144803.302233-4-hannes@xxxxxxxxxxx Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Reviewed-by: Roman Gushchin <guro@xxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) --- a/mm/vmscan.c~mm-vmscan-move-inactive_list_is_low-swap-check-to-the-caller +++ a/mm/vmscan.c @@ -2226,13 +2226,6 @@ static bool inactive_list_is_low(struct 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 pgl * 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); } _
