On Fri 30-09-22 19:14:33, Kamalesh Babulal wrote:
> Replace the checks for memcg is root memcg, with mem_cgroup_is_root()
> helper.
>
> Signed-off-by: Kamalesh Babulal <kamalesh.babulal@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks!
> ---
> mm/memcontrol.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index b69979c9ced5..99b3d0cbd426 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1148,7 +1148,7 @@ static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg)
> * cgroup root (root_mem_cgroup). So we have to handle
> * dead_memcg from cgroup root separately.
> */
> - if (last != root_mem_cgroup)
> + if (!mem_cgroup_is_root(last))
> __invalidate_reclaim_iterators(root_mem_cgroup,
> dead_memcg);
> }
> @@ -1172,7 +1172,7 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
> struct mem_cgroup *iter;
> int ret = 0;
>
> - BUG_ON(memcg == root_mem_cgroup);
> + BUG_ON(mem_cgroup_is_root(memcg));
>
> for_each_mem_cgroup_tree(iter, memcg) {
> struct css_task_iter it;
> @@ -1201,7 +1201,7 @@ void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
> memcg = folio_memcg(folio);
>
> if (!memcg)
> - VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio);
> + VM_BUG_ON_FOLIO(!mem_cgroup_is_root(lruvec_memcg(lruvec)), folio);
> else
> VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio);
> }
> @@ -1982,7 +1982,7 @@ struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
> rcu_read_lock();
>
> memcg = mem_cgroup_from_task(victim);
> - if (memcg == root_mem_cgroup)
> + if (mem_cgroup_is_root(memcg))
> goto out;
>
> /*
> @@ -2940,7 +2940,7 @@ static struct obj_cgroup *__get_obj_cgroup_from_memcg(struct mem_cgroup *memcg)
> {
> struct obj_cgroup *objcg = NULL;
>
> - for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) {
> + for (; !mem_cgroup_is_root(memcg); memcg = parent_mem_cgroup(memcg)) {
> objcg = rcu_dereference(memcg->objcg);
> if (objcg && obj_cgroup_tryget(objcg))
> break;
> @@ -7073,7 +7073,7 @@ void mem_cgroup_sk_alloc(struct sock *sk)
>
> rcu_read_lock();
> memcg = mem_cgroup_from_task(current);
> - if (memcg == root_mem_cgroup)
> + if (mem_cgroup_is_root(memcg))
> goto out;
> if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active)
> goto out;
> @@ -7208,7 +7208,7 @@ static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
> * The root cgroup cannot be destroyed, so it's refcount must
> * always be >= 1.
> */
> - if (WARN_ON_ONCE(memcg == root_mem_cgroup)) {
> + if (WARN_ON_ONCE(mem_cgroup_is_root(memcg))) {
> VM_BUG_ON(1);
> break;
> }
> @@ -7369,7 +7369,7 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
>
> if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
> return nr_swap_pages;
> - for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg))
> + for (; !mem_cgroup_is_root(memcg); memcg = parent_mem_cgroup(memcg))
> nr_swap_pages = min_t(long, nr_swap_pages,
> READ_ONCE(memcg->swap.max) -
> page_counter_read(&memcg->swap));
> @@ -7391,7 +7391,7 @@ bool mem_cgroup_swap_full(struct page *page)
> if (!memcg)
> return false;
>
> - for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) {
> + for (; !mem_cgroup_is_root(memcg); memcg = parent_mem_cgroup(memcg)) {
> unsigned long usage = page_counter_read(&memcg->swap);
>
> if (usage * 2 >= READ_ONCE(memcg->swap.high) ||
> @@ -7556,7 +7556,7 @@ bool obj_cgroup_may_zswap(struct obj_cgroup *objcg)
> return true;
>
> original_memcg = get_mem_cgroup_from_objcg(objcg);
> - for (memcg = original_memcg; memcg != root_mem_cgroup;
> + for (memcg = original_memcg; !mem_cgroup_is_root(memcg);
> memcg = parent_mem_cgroup(memcg)) {
> unsigned long max = READ_ONCE(memcg->zswap_max);
> unsigned long pages;
>
> base-commit: 987a926c1d8a40e4256953b04771fbdb63bc7938
> --
> 2.34.3
--
Michal Hocko
SUSE Labs
