Re: [patch 2/3] memcg: prevent endless loop when charging huge pages to near-limit group

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 1 Feb 2011 01:04:55 +0100
Johannes Weiner <hannes@cmpxchg.org> wrote:

> Maybe it would be better to use res_counter_margin(cnt) >= wanted
> throughout the code.

yup.

> --- a/include/linux/res_counter.h
> +++ b/include/linux/res_counter.h
> @@ -182,6 +182,14 @@ static inline bool res_counter_check_under_limit(struct res_counter *cnt)
>  	return ret;
>  }
>  
> +/**
> + * res_counter_check_margin - check if the counter allows charging
> + * @cnt: the resource counter to check
> + * @bytes: the number of bytes to check the remaining space against
> + *
> + * Returns a boolean value on whether the counter can be charged
> + * @bytes or whether this would exceed the limit.
> + */
>  static inline bool res_counter_check_margin(struct res_counter *cnt,
>  					    unsigned long bytes)
>  {

mem_cgroup_check_margin() needs some lipstick too.