diff mbox series

[net-next,5/5] ipv6: refactor ip6_finish_output2()

Message ID bd02b2a2e1c8ba93f48cad589f0354635a65d6f1.1651141755.git.asml.silence@gmail.com (mailing list archive)
State Accepted
Commit 58f71be58b8713e41f8568938a0199190f723d1d
Delegated to: Netdev Maintainers
Headers show
Series generic net and ipv6 minor optimisations | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 2 maintainers not CCed: yoshfuji@linux-ipv6.org pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: nested (un)?likely() calls, IS_ERR_OR_NULL already uses unlikely() internally
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Pavel Begunkov April 28, 2022, 10:58 a.m. UTC 
Throw neigh checks in ip6_finish_output2() under a single slow path if,
so we don't have the overhead in the hot path.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 net/ipv6/ip6_output.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index bda1d9f76f7e..afa5bd4ad167 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -119,19 +119,21 @@  static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *
 	rcu_read_lock_bh();
 	nexthop = rt6_nexthop((struct rt6_info *)dst, daddr);
 	neigh = __ipv6_neigh_lookup_noref(dev, nexthop);
-	if (unlikely(!neigh))
-		neigh = __neigh_create(&nd_tbl, nexthop, dev, false);
-	if (!IS_ERR(neigh)) {
-		sock_confirm_neigh(skb, neigh);
-		ret = neigh_output(neigh, skb, false);
-		rcu_read_unlock_bh();
-		return ret;
+
+	if (unlikely(IS_ERR_OR_NULL(neigh))) {
+		if (unlikely(!neigh))
+			neigh = __neigh_create(&nd_tbl, nexthop, dev, false);
+		if (IS_ERR(neigh)) {
+			rcu_read_unlock_bh();
+			IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES);
+			kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);
+			return -EINVAL;
+		}
 	}
+	sock_confirm_neigh(skb, neigh);
+	ret = neigh_output(neigh, skb, false);
 	rcu_read_unlock_bh();
-
-	IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES);
-	kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);
-	return -EINVAL;
+	return ret;
 }
 
 static int