From 03485f2adcde0c2d4e9228b659be78e872486bbb Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Sat, 31 Jan 2015 10:40:17 -0500 Subject: [PATCH] udpv6: Add lockless sendmsg() support This commit adds the same functionaliy to IPv6 that commit 903ab86d195cca295379699299c5fc10beba31c7 Author: Herbert Xu Date: Tue Mar 1 02:36:48 2011 +0000 udp: Add lockless transmit path added to IPv4. UDP transmit path can now run without a socket lock, thus allowing multiple threads to send to a single socket more efficiently. This is only used when corking/MSG_MORE is not used. Signed-off-by: Vladislav Yasevich Signed-off-by: David S. Miller --- net/ipv6/udp.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 67a3d70f7ac4..d048d46779fc 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1177,6 +1177,7 @@ do_udp_sendmsg: if (len > INT_MAX - sizeof(struct udphdr)) return -EMSGSIZE; + getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; if (up->pending) { /* * There are pending frames. @@ -1307,6 +1308,20 @@ do_udp_sendmsg: goto do_confirm; back_from_confirm: + /* Lockless fast path for the non-corking case */ + if (!corkreq) { + struct sk_buff *skb; + + skb = ip6_make_skb(sk, getfrag, msg, ulen, + sizeof(struct udphdr), hlimit, tclass, opt, + &fl6, (struct rt6_info *)dst, + msg->msg_flags, dontfrag); + err = PTR_ERR(skb); + if (!IS_ERR_OR_NULL(skb)) + err = udp_v6_send_skb(skb, &fl6); + goto release_dst; + } + lock_sock(sk); if (unlikely(up->pending)) { /* The socket is already corked while preparing it. */ @@ -1324,7 +1339,6 @@ do_append_data: if (dontfrag < 0) dontfrag = np->dontfrag; up->len += ulen; - getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), hlimit, tclass, opt, &fl6, (struct rt6_info *)dst, @@ -1336,6 +1350,11 @@ do_append_data: else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) up->pending = 0; + if (err > 0) + err = np->recverr ? net_xmit_errno(err) : 0; + release_sock(sk); + +release_dst: if (dst) { if (connected) { ip6_dst_store(sk, dst, @@ -1352,9 +1371,6 @@ do_append_data: dst = NULL; } - if (err > 0) - err = np->recverr ? net_xmit_errno(err) : 0; - release_sock(sk); out: dst_release(dst); fl6_sock_release(flowlabel); -- 2.20.1