Re: [patch 09/11] mm: memcg: split swapin charge function into private and public part

[Michal Hocko <mhocko@suse.cz>]

On Thu 05-07-12 02:45:01, Johannes Weiner wrote:
> When shmem is charged upon swapin, it does not need to check twice
> whether the memory controller is enabled.
> 
> Also, shmem pages do not have to be checked for everything that
> regular anon pages have to be checked for, so let shmem use the
> internal version directly and allow future patches to move around
> checks that are only required when swapping in anon pages.
> 
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

Acked-by: Michal Hocko <mhocko@suse.cz>

> ---
>  mm/memcontrol.c |   24 +++++++++++++++---------
>  1 files changed, 15 insertions(+), 9 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 6fe4101..a8bf86a 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2734,18 +2734,14 @@ int mem_cgroup_newpage_charge(struct page *page,
>   * struct page_cgroup is acquired. This refcnt will be consumed by
>   * "commit()" or removed by "cancel()"
>   */
> -int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
> -				 struct page *page,
> -				 gfp_t mask, struct mem_cgroup **memcgp)
> +static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
> +					  struct page *page,
> +					  gfp_t mask,
> +					  struct mem_cgroup **memcgp)
>  {
>  	struct mem_cgroup *memcg;
>  	int ret;
>  
> -	*memcgp = NULL;
> -
> -	if (mem_cgroup_disabled())
> -		return 0;
> -
>  	if (!do_swap_account)
>  		goto charge_cur_mm;
>  	/*
> @@ -2772,6 +2768,15 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
>  	return ret;
>  }
>  
> +int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
> +				 gfp_t gfp_mask, struct mem_cgroup **memcgp)
> +{
> +	*memcgp = NULL;
> +	if (mem_cgroup_disabled())
> +		return 0;
> +	return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp);
> +}
> +
>  void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
>  {
>  	if (mem_cgroup_disabled())
> @@ -2833,7 +2838,8 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
>  	if (!PageSwapCache(page))
>  		ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
>  	else { /* page is swapcache/shmem */
> -		ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
> +		ret = __mem_cgroup_try_charge_swapin(mm, page,
> +						     gfp_mask, &memcg);
>  		if (!ret)
>  			__mem_cgroup_commit_charge_swapin(page, memcg, type);
>  	}
> -- 
> 1.7.7.6
> 

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic