Re: [PATCH] memcg: correct return value at mem_cgroup reclaim

[Balbir Singh <balbir@linux.vnet.ibm.com>]

* Daisuke Nishimura <d-nishimura@mtf.biglobe.ne.jp> [2009-12-06 22:30:46]:

> hi,
> 
> On Sun, 6 Dec 2009 18:16:14 +0800
> Liu bo <bo-liu@hotmail.com> wrote:
> 
> > 
> > In order to indicate reclaim has succeeded, mem_cgroup_hierarchical_reclaim() used to return 1.
> > Now the return value is without indicating whether reclaim has successded usage, so just return the total reclaimed pages don't plus 1.
> >  
> > Signed-off-by: Liu Bo <bo-liu@hotmail.com>
> > ---
> >  
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index 14593f5..51b6b3c 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -737,7 +737,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
> >    css_put(&victim->css);
> >    total += ret;
> >    if (mem_cgroup_check_under_limit(root_mem))
> > -   return 1 + total;
> > +   return total;
> >   }
> >   return total;
> >  } 		 	   		  
> What's the benefit of this change ?
> I can't find any benefit to bother changing current behavior.
>

I agree, I added the "1 +" for a reason, if the new group is under its
limit magically without us having to reclaim anything (task exits or
memory freed), I don't want to look at total and see we reclaimed
nothing and take action.
 
> P.S.
> You should run ./scripts/checkpatch.pl before sending your patch,
> and refer to Documentation/email-clients.txt and check your email client setting.
>

Yes, the tabbing and spaces seem to be broken 

-- 
	Balbir

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