Re: [PATCH] net/core: use xx_zalloc instead xx_alloc and memset

[Joe Perches]

On Wed, 2020-11-18 at 16:15 +0800, Tian Tao wrote:
> use kmem_cache_zalloc instead kmem_cache_alloc and memset.
[]
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
[]
> @@ -313,12 +313,10 @@ struct sk_buff *__build_skb(void *data, unsigned int 
> frag_size)
>  {
>       struct sk_buff *skb;
>  
> -     skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC);
> +     skb = kmem_cache_zalloc(skbuff_head_cache, GFP_ATOMIC);
>       if (unlikely(!skb))
>               return NULL;
>  
> -     memset(skb, 0, offsetof(struct sk_buff, tail));
> -
>       return __build_skb_around(skb, data, frag_size);
>  }
>  
> 
> @@ -6170,12 +6168,10 @@ static void *skb_ext_get_ptr(struct skb_ext *ext, 
> enum skb_ext_id id)
>   */
>  struct skb_ext *__skb_ext_alloc(gfp_t flags)
>  {
> -     struct skb_ext *new = kmem_cache_alloc(skbuff_ext_cache, flags);
> +     struct skb_ext *new = kmem_cache_zalloc(skbuff_ext_cache, flags);
>  
> -     if (new) {
> -             memset(new->offset, 0, sizeof(new->offset));
> +     if (new)
>               refcount_set(&new->refcnt, 1);
> -     }
>  
>       return new;
>  }

I think it'd be nicer to use the same form for both of these functions.
This could be:

struct skb_ext *__skb_ext_alloc(gfp_t flags)
{
        struct skb_ext *new;

        new = kmem_cache_zalloc(skbbuff_ext_cache, flags);
        if (unlikely(!new))
                return NULL;

        refcount_set(&new->refcnt, 1);

        return new;
}