Commit 2a4319cf authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: lockless implementation of SO_BUSY_POLL, SO_PREFER_BUSY_POLL, SO_BUSY_POLL_BUDGET 



Setting sk->sk_ll_usec, sk_prefer_busy_poll and sk_busy_poll_budget
do not require the socket lock, readers are lockless anyway.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b1202515

net/core/sock.c

+20 −24
Original line number Diff line number Diff line
@@ -1140,6 +1140,26 @@ int sk_setsockopt(struct sock *sk, int level, int optname, 
	case SO_DOMAIN:

	case SO_ERROR:

		return -ENOPROTOOPT;

#ifdef CONFIG_NET_RX_BUSY_POLL

	case SO_BUSY_POLL:

		if (val < 0)

			return -EINVAL;

		WRITE_ONCE(sk->sk_ll_usec, val);

		return 0;

	case SO_PREFER_BUSY_POLL:

		if (valbool && !sockopt_capable(CAP_NET_ADMIN))

			return -EPERM;

		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);

		return 0;

	case SO_BUSY_POLL_BUDGET:

		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&

		    !sockopt_capable(CAP_NET_ADMIN))

			return -EPERM;

		if (val < 0 || val > U16_MAX)

			return -EINVAL;

		WRITE_ONCE(sk->sk_busy_poll_budget, val);

		return 0;

#endif

	}



	sockopt_lock_sock(sk);
@@ -1402,30 +1422,6 @@ int sk_setsockopt(struct sock *sk, int level, int optname, 
		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);

		break;



#ifdef CONFIG_NET_RX_BUSY_POLL

	case SO_BUSY_POLL:

		if (val < 0)

			ret = -EINVAL;

		else

			WRITE_ONCE(sk->sk_ll_usec, val);

		break;

	case SO_PREFER_BUSY_POLL:

		if (valbool && !sockopt_capable(CAP_NET_ADMIN))

			ret = -EPERM;

		else

			WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);

		break;

	case SO_BUSY_POLL_BUDGET:

		if (val > READ_ONCE(sk->sk_busy_poll_budget) && !sockopt_capable(CAP_NET_ADMIN)) {

			ret = -EPERM;

		} else {

			if (val < 0 || val > U16_MAX)

				ret = -EINVAL;

			else

				WRITE_ONCE(sk->sk_busy_poll_budget, val);

		}

		break;

#endif



	case SO_MAX_PACING_RATE:

		{