Re: [RFC PATCH] memcg: oom: fix totalpages calculation forswappiness==0

[Michal Hocko]

On Mon 15-10-12 10:25:14, KOSAKI Motohiro wrote:
> > diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
> > index 078701f..308fd77 100644
> > --- a/Documentation/sysctl/vm.txt
> > +++ b/Documentation/sysctl/vm.txt
> > @@ -640,6 +640,9 @@ swappiness
> >  This control is used to define how aggressive the kernel will swap
> >  memory pages.  Higher values will increase agressiveness, lower values
> >  decrease the amount of swap.
> > +The value can be used from the [0, 100] range, where 0 means no swapping
> > +at all (even if there is a swap storage enabled) while 100 means that
> > +anonymous pages are reclaimed in the same rate as file pages.
> 
> I think this only correct when memcg. Even if swappiness==0, global reclaim swap
> out anon pages before oom.

Right you are (we really do swap when the file pages are really
low)! Sorry about the confusion. I kind of became if(global_reclaim)
block blind...

Then this really needs a memcg specific documentation fix. What about
the following?
---