Re: [PATCH v4 1/5] mm/memcg: Move mod_objcg_state() to memcontrol.c

[Waiman Long <llong@redhat.com>]

On 4/19/21 11:21 AM, Waiman Long wrote:
> On 4/19/21 11:14 AM, Johannes Weiner wrote:
>> On Sun, Apr 18, 2021 at 08:00:28PM -0400, Waiman Long wrote:
>>> The mod_objcg_state() function is moved from mm/slab.h to 
>>> mm/memcontrol.c
>>> so that further optimization can be done to it in later patches without
>>> exposing unnecessary details to other mm components.
>>>
>>> Signed-off-by: Waiman Long <longman@redhat.com>
>>> ---
>>>   mm/memcontrol.c | 13 +++++++++++++
>>>   mm/slab.h       | 16 ++--------------
>>>   2 files changed, 15 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>>> index e064ac0d850a..dc9032f28f2e 100644
>>> --- a/mm/memcontrol.c
>>> +++ b/mm/memcontrol.c
>>> @@ -3150,6 +3150,19 @@ void __memcg_kmem_uncharge_page(struct page 
>>> *page, int order)
>>>       css_put(&memcg->css);
>>>   }
>>>   +void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data 
>>> *pgdat,
>>> +             enum node_stat_item idx, int nr)
>>> +{
>>> +    struct mem_cgroup *memcg;
>>> +    struct lruvec *lruvec = NULL;
>>> +
>>> +    rcu_read_lock();
>>> +    memcg = obj_cgroup_memcg(objcg);
>>> +    lruvec = mem_cgroup_lruvec(memcg, pgdat);
>>> +    mod_memcg_lruvec_state(lruvec, idx, nr);
>>> +    rcu_read_unlock();
>>> +}
>> It would be more naturally placed next to the others, e.g. below
>> __mod_lruvec_kmem_state().
>>
>> But no deal breaker if there isn't another revision.
>>
>> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
>>
> Yes, there will be another revision by rebasing patch series on the 
> linux-next. I will move the function then. 

OK, it turns out that mod_objcg_state() is only defined if 
CONFIG_MEMCG_KMEM. That was why I put it in the CONFIG_MEMCG_KMEM block 
with the other obj_stock functions. I think I will keep it there.

Thanks,
Longman