[Devel] Re: [ckrm-tech] [RFC][PATCH] UBC: user resource beancounters

[Chandra Seetharaman]

On Fri, 2006-08-25 at 21:46 +0100, Alan Cox wrote:
> Ar Gwe, 2006-08-25 am 11:21 -0700, ysgrifennodd Chandra Seetharaman:
> > But, the problem is that the struct user_beancounter (part of
> > wombat_controller above) is a _copy_ of the original, not the original
> > itself. We cannot keep the original (in _each_ controller), as there may
> > be more than one controller in the system 
> 
> Why would you want more than one controller for a given beancounter (and
> thus a single measured resource). Can you give an example ?
> 

Hmm... from what I see, data structure user_beancounter is _not_ defined
for a single resource, it is a beancounter for _all_ resources.

struct user_beancounter
{
	atomic_t		ub_refcount;
	spinlock_t		ub_lock;
	uid_t			ub_uid;
	struct hlist_node	hash;

	struct user_beancounter	*parent;
	void			*private_data;

	/* resources statistics and settings */
	struct ubparm		ub_parms[UB_RESOURCES];
};

ub_parms of _all_ controllers are held in this data structure.

So, keeping the beancounter data structure inside _a_ controller
specific data structure doesn't sound right to me, as other controllers
might also have the same need ?!

Controller _owns_ only ub_parms[controller_id], not the whole
user_beancounter, right ?

-- 

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    Chandra Seetharaman               | Be careful what you choose....
              - sekharan at us.ibm.com   |      .......you may get it.
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