net: add add indirect call wrapper in skb_release_head_state()

While stress testing UDP senders on a host with expensive indirect
calls, I found cpus processing TX completions where showing
a very high cost (20%) in sock_wfree() due to
CONFIG_MITIGATION_RETPOLINE=y.

Take care of TCP and UDP TX destructors and use INDIRECT_CALL_3() macro.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251014171907.3554413-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6be01454f262a2acbf3f5905498961d132442d2c..8eb3c58207243f0575481e5b55d8691ff49e8c4d 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1136,7 +1136,16 @@ void skb_release_head_state(struct sk_buff *skb)
        skb_dst_drop(skb);
        if (skb->destructor) {
                DEBUG_NET_WARN_ON_ONCE(in_hardirq());
-               skb->destructor(skb);
+#ifdef CONFIG_INET
+               INDIRECT_CALL_3(skb->destructor,
+                               tcp_wfree, __sock_wfree, sock_wfree,
+                               skb);
+#else
+               INDIRECT_CALL_1(skb->destructor,
+                               sock_wfree,
+                               skb);
+
+#endif
        }
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
        nf_conntrack_put(skb_nfct(skb));