linux-kernel - Re: [PATCH 1/3] mm/swap: simplify alloc_swap_slot

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Date:   Fri, 1 May 2020 14:46:31 -0700
From:   Tim Chen <tim.c.chen@...ux.intel.com>
To:     Zhen Lei <thunder.leizhen@...wei.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-mm <linux-mm@...ck.org>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/3] mm/swap: simplify alloc_swap_slot_cache()



On 4/29/20 11:11 PM, Zhen Lei wrote:
> Both "slots" and "slots_ret" are only need to be freed when cache already
> allocated. Make them closer, seems more clear.
> 
> No functional change.
> 
> Signed-off-by: Zhen Lei <thunder.leizhen@...wei.com>
> ---
>  mm/swap_slots.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> index 0975adc72253..01609b5f0c55 100644
> --- a/mm/swap_slots.c
> +++ b/mm/swap_slots.c
> @@ -136,9 +136,16 @@ static int alloc_swap_slot_cache(unsigned int cpu)
>  
>  	mutex_lock(&swap_slots_cache_mutex);
>  	cache = &per_cpu(swp_slots, cpu);
> -	if (cache->slots || cache->slots_ret)
> +	if (cache->slots || cache->slots_ret) {
>  		/* cache already allocated */
> -		goto out;
> +		mutex_unlock(&swap_slots_cache_mutex);
> +
> +		kvfree(slots);
> +		kvfree(slots_ret);
> +
> +		return 0;
> +	}
> +
>  	if (!cache->lock_initialized) {
>  		mutex_init(&cache->alloc_lock);
>  		spin_lock_init(&cache->free_lock);
> @@ -155,15 +162,8 @@ static int alloc_swap_slot_cache(unsigned int cpu)
>  	 */
>  	mb();
>  	cache->slots = slots;
> -	slots = NULL;
>  	cache->slots_ret = slots_ret;
> -	slots_ret = NULL;
> -out:
>  	mutex_unlock(&swap_slots_cache_mutex);
> -	if (slots)
> -		kvfree(slots);
> -	if (slots_ret)
> -		kvfree(slots_ret);
>  	return 0;
>  }
>  
> 

Acked-by: Tim Chen <tim.c.chen@...ux.intel.com>