Re: [PATCH] mm/memcg: wrap mem_cgroup_from_css function

[Gavin Shan <shangw@linux.vnet.ibm.com>]

On Thu, Jul 19, 2012 at 05:23:09PM +0800, Wanpeng Li wrote:
>On Thu, Jul 19, 2012 at 12:14:20PM +0300, Kirill A. Shutemov wrote:
>>On Wed, Jul 18, 2012 at 11:05:30AM +0800, Wanpeng Li wrote:
>>> wrap mem_cgroup_from_css function to clarify get mem cgroup
>>> from cgroup_subsys_state.
>>> 
>>> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
>>> Cc: Michal Hocko <mhocko@suse.cz>
>>> Cc: Johannes Weiner <hannes@cmpxchg.org>
>>> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>> Cc: Andrew Morton <akpm@linux-foundation.org>
>>> Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
>>> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
>>> Cc: linux-kernel@vger.kernel.org
>>> ---
>>>  mm/memcontrol.c |   14 ++++++++++----
>>>  1 files changed, 10 insertions(+), 4 deletions(-)
>>> 
>>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>>> index 58a08fc..20f6a15 100644
>>> --- a/mm/memcontrol.c
>>> +++ b/mm/memcontrol.c
>>> @@ -396,6 +396,12 @@ static void mem_cgroup_put(struct mem_cgroup *memcg);
>>>  #include <net/sock.h>
>>>  #include <net/ip.h>
>>>  
>>> +static inline
>>> +struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
>>> +{
>>> +	return container_of(s, struct mem_cgroup, css);
>>> +}
>>> +
>>>  static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
>>>  void sock_update_memcg(struct sock *sk)
>>>  {
>>> @@ -820,7 +826,7 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
>>>  
>>>  struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
>>>  {
>>> -	return container_of(cgroup_subsys_state(cont,
>>> +	return mem_cgroup_from_css(cgroup_subsys_state(cont,
>>>  				mem_cgroup_subsys_id), struct mem_cgroup,
>>>  				css);
>>
>>Hm?.. Here and below too many args to mem_cgroup_from_css().
>>Have you tested the code?
>
>Hi, what's the meaning of "two many"?
>

It might be the typo for "two" here. I think it would be
"too". However, it seems that you had pass "two" more arguments
here to mem_cgroup_from_css() since the function only takes "one"
parameter as you implemented before.

+struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)

+   return mem_cgroup_from_css(cgroup_subsys_state(cont,
+		mem_cgroup_subsys_id), struct mem_cgroup,
+		css);

Thanks,
Gavin

>cgroup_subsys_state(cont, mem_cgroup_subsys_id) and 
>task_subsys_state(p, mem_cgroup_subsys_id) both are 
>just one arg in mem_cgroup_from_css. :-)
>
>>
>>>  }
>>> @@ -835,7 +841,7 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
>>>  	if (unlikely(!p))
>>>  		return NULL;
>>>  
>>> -	return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
>>> +	return mem_cgroup_from_css(task_subsys_state(p, mem_cgroup_subsys_id),
>>>  				struct mem_cgroup, css);
>>>  }
>>>  
>>> @@ -922,7 +928,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
>>>  		css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
>>>  		if (css) {
>>>  			if (css == &root->css || css_tryget(css))
>>> -				memcg = container_of(css,
>>> +				memcg = mem_cgroup_from_css(css,
>>>  						     struct mem_cgroup, css);
>>>  		} else
>>>  			id = 0;
>>> @@ -2406,7 +2412,7 @@ static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
>>>  	css = css_lookup(&mem_cgroup_subsys, id);
>>>  	if (!css)
>>>  		return NULL;
>>> -	return container_of(css, struct mem_cgroup, css);
>>> +	return mem_cgroup_from_css(css, struct mem_cgroup, css);
>>>  }
>>>  
>>>  struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
>>> -- 
>>> 1.7.5.4
>>> 
>>> --
>>> To unsubscribe, send a message with 'unsubscribe linux-mm' in
>>> the body to majordomo@kvack.org.  For more info on Linux MM,
>>> see: http://www.linux-mm.org/ .
>>> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
>>
>>-- 
>> Kirill A. Shutemov

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>