+cc: Andrew Morton
Sorry, had missed akpm in the original patch.
On 10/3/22 13:28, Michal Hocko wrote:
> 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!
>
Michal Hocko/Muchun Song,
Thank you so much for the review.
>> ---
>> 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
>
--
Thanks,
Kamalesh
