[PATCH 2/2] memcg: dirty pages instrumentation

[David Rientjes]

On Sun, 21 Feb 2010, Andrea Righi wrote:

> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 0b19943..c9ff1cd 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -137,10 +137,11 @@ static struct prop_descriptor vm_dirties;
>   */
>  static int calc_period_shift(void)
>  {
> -	unsigned long dirty_total;
> +	unsigned long dirty_total, dirty_bytes;
>  
> -	if (vm_dirty_bytes)
> -		dirty_total = vm_dirty_bytes / PAGE_SIZE;
> +	dirty_bytes = mem_cgroup_dirty_bytes();
> +	if (dirty_bytes)
> +		dirty_total = dirty_bytes / PAGE_SIZE;
>  	else
>  		dirty_total = (vm_dirty_ratio * determine_dirtyable_memory()) /
>  				100;

This needs a comment since mem_cgroup_dirty_bytes() doesn't imply that it 
is responsible for returning the global vm_dirty_bytes when that's 
actually what it does (both for CONFIG_CGROUP_MEM_RES_CTRL=n and root 
cgroup).