From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Willem de Bruijn <willemb@google.com>,
Mahesh Bandewar <maheshb@google.com>
Cc: netdev <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: [PATCH net-next 8/8] net/packet: introduce packet_rcv_try_clear_pressure() helper
Date: Wed, 12 Jun 2019 09:52:33 -0700 [thread overview]
Message-ID: <20190612165233.109749-9-edumazet@google.com> (raw)
In-Reply-To: <20190612165233.109749-1-edumazet@google.com>
There are two places where we want to clear the pressure
if possible, add a helper to make it more obvious.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Willem de Bruijn <willemb@google.com>
---
net/packet/af_packet.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d409e2fdaa7ee8ddf261354f91b682e403f40e9e..8c27e198268ab5148daa8e90aa2f53546623b9ed 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1271,6 +1271,13 @@ static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
return ret;
}
+static void packet_rcv_try_clear_pressure(struct packet_sock *po)
+{
+ if (READ_ONCE(po->pressure) &&
+ __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
+ WRITE_ONCE(po->pressure, 0);
+}
+
static void packet_sock_destruct(struct sock *sk)
{
skb_queue_purge(&sk->sk_error_queue);
@@ -3308,8 +3315,7 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
if (skb == NULL)
goto out;
- if (READ_ONCE(pkt_sk(sk)->pressure))
- packet_rcv_has_room(pkt_sk(sk), NULL);
+ packet_rcv_try_clear_pressure(pkt_sk(sk));
if (pkt_sk(sk)->has_vnet_hdr) {
err = packet_rcv_vnet(msg, skb, &len);
@@ -4127,8 +4133,7 @@ static __poll_t packet_poll(struct file *file, struct socket *sock,
TP_STATUS_KERNEL))
mask |= EPOLLIN | EPOLLRDNORM;
}
- if (READ_ONCE(po->pressure) && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
- WRITE_ONCE(po->pressure, 0);
+ packet_rcv_try_clear_pressure(po);
spin_unlock_bh(&sk->sk_receive_queue.lock);
spin_lock_bh(&sk->sk_write_queue.lock);
if (po->tx_ring.pg_vec) {
--
2.22.0.rc2.383.gf4fbbf30c2-goog
next prev parent reply other threads:[~2019-06-12 16:53 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 16:52 [PATCH net-next 0/8] net/packet: better behavior under DDOS Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 1/8] net/packet: constify __packet_get_status() argument Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 2/8] net/packet: constify packet_lookup_frame() and __tpacket_has_room() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 3/8] net/packet: constify prb_lookup_block() and __tpacket_v3_has_room() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 4/8] net/packet: constify __packet_rcv_has_room() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 5/8] net/packet: make tp_drops atomic Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 6/8] net/packet: implement shortcut in tpacket_rcv() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 7/8] net/packet: remove locking from packet_rcv_has_room() Eric Dumazet
2019-06-12 16:52 ` Eric Dumazet [this message]
2019-06-13 0:11 ` [PATCH net-next 8/8] net/packet: introduce packet_rcv_try_clear_pressure() helper Vinicius Costa Gomes
2019-06-12 17:15 ` [PATCH net-next 0/8] net/packet: better behavior under DDOS Willem de Bruijn
2019-06-15 1:53 ` David Miller
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