Re: [PATCH net-next v15 11/14] net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags

On 6/27/24 6:32 PM, Mina Almasry wrote:

@@ -1049,6 +1050,62 @@ static int sock_reserve_memory(struct sock *sk, int bytes) return 0; } +#ifdef CONFIG_PAGE_POOL +static noinline_for_stack int +sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) +{

• unsigned int num_tokens, i, j, k, netmem_num = 0;
• struct dmabuf_token *tokens;
• netmem_ref netmems[16];
• int ret = 0;
• if (sk->sk_type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP)

• return -EBADF;
  

• if (optlen % sizeof(struct dmabuf_token) ||

•    optlen > sizeof(*tokens) * 128)
  

• return -EINVAL;
  

• tokens = kvmalloc_array(128, sizeof(*tokens), GFP_KERNEL);

The '128' should be a named macro with a comment on why that value.