[Devel] Re: [ckrm-tech] [PATCH 11/13] BC: vmrss (preparations)

[Balbir Singh]

Kirill Korotaev wrote:
> This patch does simple things:
> - intruduces an bc_magic field on beancunter to make sure
>   union on struct page is correctly used in next patches
> - adds nr_beancounters
> - adds unused_privvmpages variable (counter of privvm pages
>   which are not mapped into VM address space and thus potentially
>   can be allocated later)
> 
> +static inline void privvm_uncharge(struct beancounter *bc, unsigned long sz)
> +{
> +	if (unlikely(bc->unused_privvmpages < sz)) {
> +		printk("BC: overuncharging %d unused pages: val %lu held %lu\n",
> +				bc->bc_id, sz, bc->unused_privvmpages);

I hit this path, when I do not enable CONFIG_BEANCOUNTERS_RSS. I suspect it has
something to do with the code in mod_rss_pages(). I suspect the that
CONFIG_BEANCOUNTERS_RSS needs to be enabled to get the accounting right.

In addition, Could you please make this a warning with KERN_WARNING.

> +		sz = bc->unused_privvmpages;
> +	}
> +	bc->unused_privvmpages -= sz;
> +	bc_update_privvmpages(bc);
> +}
> +
-- 

	Balbir Singh,
	Linux Technology Center,
	IBM Software Labs