Re: [PATCH net-next] ipv6: sr: static percpu allocation for hmac_ring

[David Lebrun <david.lebrun@uclouvain.be>]

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On 01/12/2017 05:50 PM, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
> 
> Current allocations are not NUMA aware, and lack proper
> cleanup in case of error.
> 
> It is perfectly fine to use static per cpu allocations for 256 bytes
> per cpu.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: David Lebrun <david.lebrun@uclouvain.be>
> ---
>  net/ipv6/seg6_hmac.c |   43 ++---------------------------------------
>  1 file changed, 3 insertions(+), 40 deletions(-)
> 
> diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c
> index ef1c8a46e7aceee45b2044d4b4338dc3aed88807..6389bf3e9c9f28cdd3e30175f2880b74e099e273 100644
> --- a/net/ipv6/seg6_hmac.c
> +++ b/net/ipv6/seg6_hmac.c
> @@ -45,7 +45,7 @@
>  #include <net/seg6_hmac.h>
>  #include <linux/random.h>
>  
> -static char * __percpu *hmac_ring;
> +static DEFINE_PER_CPU(char [SEG6_HMAC_RING_SIZE], hmac_ring);
>  
>  static int seg6_hmac_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
>  {
> @@ -192,7 +192,7 @@ int seg6_hmac_compute(struct seg6_hmac_info *hinfo, struct ipv6_sr_hdr *hdr,
>  	 */
>  
>  	local_bh_disable();
> -	ring = *this_cpu_ptr(hmac_ring);
> +	ring = this_cpu_ptr(hmac_ring);
>  	off = ring;
>  
>  	/* source address */
> @@ -353,27 +353,6 @@ int seg6_push_hmac(struct net *net, struct in6_addr *saddr,
>  }
>  EXPORT_SYMBOL(seg6_push_hmac);
>  
> -static int seg6_hmac_init_ring(void)
> -{
> -	int i;
> -
> -	hmac_ring = alloc_percpu(char *);
> -
> -	if (!hmac_ring)
> -		return -ENOMEM;
> -
> -	for_each_possible_cpu(i) {
> -		char *ring = kzalloc(SEG6_HMAC_RING_SIZE, GFP_KERNEL);
> -
> -		if (!ring)
> -			return -ENOMEM;
> -
> -		*per_cpu_ptr(hmac_ring, i) = ring;
> -	}
> -
> -	return 0;
> -}
> -
>  static int seg6_hmac_init_algo(void)
>  {
>  	struct seg6_hmac_algo *algo;
> @@ -422,16 +401,7 @@ static int seg6_hmac_init_algo(void)
>  
>  int __init seg6_hmac_init(void)
>  {
> -	int ret;
> -
> -	ret = seg6_hmac_init_ring();
> -	if (ret < 0)
> -		goto out;
> -
> -	ret = seg6_hmac_init_algo();
> -
> -out:
> -	return ret;
> +	return seg6_hmac_init_algo();
>  }
>  EXPORT_SYMBOL(seg6_hmac_init);
>  
> @@ -450,13 +420,6 @@ void seg6_hmac_exit(void)
>  	struct seg6_hmac_algo *algo = NULL;
>  	int i, alg_count, cpu;
>  
> -	for_each_possible_cpu(i) {
> -		char *ring = *per_cpu_ptr(hmac_ring, i);
> -
> -		kfree(ring);
> -	}
> -	free_percpu(hmac_ring);
> -
>  	alg_count = sizeof(hmac_algos) / sizeof(struct seg6_hmac_algo);
>  	for (i = 0; i < alg_count; i++) {
>  		algo = &hmac_algos[i];
> 
> 

Acked-by: David Lebrun <david.lebrun@uclouvain.be>


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