2022-09-30 14:56:39

by Kamalesh Babulal

Subject: [PATCH] mm: memcontrol: use mem_cgroup_is_root() helper

Replace the checks for memcg is root memcg, with mem_cgroup_is_root()
helper.

Signed-off-by: Kamalesh Babulal <[email protected]>
---
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

2022-10-02 04:31:32

by Muchun Song

Subject: Re: [PATCH] mm: memcontrol: use mem_cgroup_is_root() helper

> On Sep 30, 2022, at 21:44, Kamalesh Babulal <[email protected]> wrote:
>
> Replace the checks for memcg is root memcg, with mem_cgroup_is_root()
> helper.
>
> Signed-off-by: Kamalesh Babulal <[email protected]>

Reviewed-by: Muchun Song <[email protected]>

Thanks.

2022-10-03 09:30:03

by Michal Hocko

Subject: Re: [PATCH] mm: memcontrol: use mem_cgroup_is_root() helper

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 <[email protected]>

Acked-by: Michal Hocko <[email protected]>
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

2022-10-13 07:07:35

by Kamalesh Babulal

Subject: Re: [PATCH] mm: memcontrol: use mem_cgroup_is_root() helper

+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 <[email protected]>
>
> Acked-by: Michal Hocko <[email protected]>
> 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