On 1 Dec 2022 15:39:22 -0700 Yu Zhao <yuzhao@xxxxxxxxxx>
> @@ -477,6 +477,16 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid)
> struct mem_cgroup_per_node *mz;
> struct mem_cgroup_tree_per_node *mctz;
>
> + if (lru_gen_enabled()) {
> + struct lruvec *lruvec = &memcg->nodeinfo[nid]->lruvec;
> +
> + /* see the comment on MEMCG_NR_GENS */
> + if (soft_limit_excess(memcg) && lru_gen_memcg_seg(lruvec) != MEMCG_LRU_HEAD)
> + lru_gen_rotate_memcg(lruvec, MEMCG_LRU_HEAD);
> +
> + return;
The heuristic of rotation is so weak a signal in the background noise
produced by prandom_u32_max(MEMCG_NR_BINS), wonder if mcgroup lru works
no fine without it.
> + }
> +
> mctz = soft_limit_tree.rb_tree_per_node[nid];
> if (!mctz)
> return;
> @@ -3526,6 +3536,9 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
> struct mem_cgroup_tree_per_node *mctz;
> unsigned long excess;
>
> + if (lru_gen_enabled())
> + return 0;
> +
> if (order > 0)
> return 0;
>
