On Tue 04-01-22 13:22:25, Yu Zhao wrote:
[...]
> +static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_control *sc)
> +{
> + struct mem_cgroup *memcg;
> + bool success = false;
> + unsigned long min_ttl = READ_ONCE(lru_gen_min_ttl);
> +
> + VM_BUG_ON(!current_is_kswapd());
> +
> + current->reclaim_state->mm_walk = &pgdat->mm_walk;
> +
> + memcg = mem_cgroup_iter(NULL, NULL, NULL);
> + do {
> + struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat);
> +
> + if (age_lruvec(lruvec, sc, min_ttl))
> + success = true;
> +
> + cond_resched();
> + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)));
> +
> + if (!success && mutex_trylock(&oom_lock)) {
> + struct oom_control oc = {
> + .gfp_mask = sc->gfp_mask,
> + .order = sc->order,
> + };
> +
> + if (!oom_reaping_in_progress())
> + out_of_memory(&oc);
> +
> + mutex_unlock(&oom_lock);
> + }
Why do you need to trigger oom killer from this path? Why cannot you
rely on the page allocator to do that like we do now?
--
Michal Hocko
SUSE Labs
