[Devel] Re: [RFC][PATCH 5/7] UBC: kernel memory accounting (core)

[Rohit Seth]

On Wed, 2006-08-16 at 11:47 -0700, Dave Hansen wrote:
> On Wed, 2006-08-16 at 19:40 +0400, Kirill Korotaev wrote:
> > --- ./include/linux/mm.h.kmemcore       2006-08-16 19:10:38.000000000
> > +0400
> > +++ ./include/linux/mm.h        2006-08-16 19:10:51.000000000 +0400
> > @@ -274,8 +274,14 @@ struct page {
> >         unsigned int gfp_mask;
> >         unsigned long trace[8];
> >  #endif
> > +#ifdef CONFIG_USER_RESOURCE
> > +       union {
> > +               struct user_beancounter *page_ub;
> > +       } bc;
> > +#endif
> >  };
> 
> Is everybody OK with adding this accounting to the 'struct page'?  

My preference would be to have container (I keep on saying container,
but resource beancounter) pointer embeded in task, mm(not sure),
address_space and anon_vma structures.  This should allow us to track
user land pages optimally.  But for tracking kernel usage on behalf of
user, we will have to use an additional field (unless we can re-use
mapping).  Please correct me if I'm wrong, though all the kernel
resources will be allocated/freed in context of a user process.  And at
that time we know if a allocation should succeed or not.  So we may
actually not need to track kernel pages that closely.  We are not going
to run reclaim on any of them anyways.  

-rohit