Re: [patch 02/11] mm: swapfile: clean up unuse_pte race handling

[Michal Hocko]

On Thu 05-07-12 02:44:54, Johannes Weiner wrote:
> The conditional mem_cgroup_cancel_charge_swapin() is a leftover from
> when the function would continue to reestablish the page even after
> mem_cgroup_try_charge_swapin() failed.  After 85d9fc8 "memcg: fix
> refcnt handling at swapoff", the condition is always true when this
> code is reached.
> 
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxx>

> ---
>  mm/swapfile.c |    3 +--
>  1 files changed, 1 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 64408be..75881ca 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -845,8 +845,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
>  
>  	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
>  	if (unlikely(!pte_same(*pte, swp_entry_to_pte(entry)))) {
> -		if (ret > 0)
> -			mem_cgroup_cancel_charge_swapin(memcg);
> +		mem_cgroup_cancel_charge_swapin(memcg);
>  		ret = 0;
>  		goto out;
>  	}
> -- 
> 1.7.7.6
> 

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/