Re: [PATCH v6 6/9] mm: multigenerational lru: aging

From: Michal Hocko
Date: Mon Jan 10 2022 - 11:57:45 EST


On Tue 04-01-22 13:22:25, Yu Zhao wrote:
[...]
> +static void walk_mm(struct lruvec *lruvec, struct mm_struct *mm, struct lru_gen_mm_walk *walk)
> +{
> + static const struct mm_walk_ops mm_walk_ops = {
> + .test_walk = should_skip_vma,
> + .p4d_entry = walk_pud_range,
> + };
> +
> + int err;
> +#ifdef CONFIG_MEMCG
> + struct mem_cgroup *memcg = lruvec_memcg(lruvec);
> +#endif
> +
> + walk->next_addr = FIRST_USER_ADDRESS;
> +
> + do {
> + unsigned long start = walk->next_addr;
> + unsigned long end = mm->highest_vm_end;
> +
> + err = -EBUSY;
> +
> + rcu_read_lock();
> +#ifdef CONFIG_MEMCG
> + if (memcg && atomic_read(&memcg->moving_account))
> + goto contended;
> +#endif

Why do you need to check for moving_account?
--
Michal Hocko
SUSE Labs