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| author |   Pavel Begunkov <asml.silence@gmail.com> | 2022-01-27 00:36:22 +0000 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2022-01-27 19:46:10 -0800 |
| commit | cd3c748077365dde89f2a3da738ce556fd04b0a3 (patch) | |
| tree | 53cded77bfc603a21aa8008e2b0a0afade5dcb69 | |
| parent | Merge branch 'mlxsw-various-updates' (diff) | |
| download | linux-dev-cd3c748077365dde89f2a3da738ce556fd04b0a3.tar.xz linux-dev-cd3c748077365dde89f2a3da738ce556fd04b0a3.zip | |
ipv6: optimise dst refcounting on skb init
__ip6_make_skb() gets a cork->dst ref, hands it over to skb and shortly
after puts cork->dst. Save two atomics by stealing it without extra
referencing, ip6_cork_release() handles NULL cork->dst.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv6/ip6_output.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 2995f8d89e7e..14d607ccfeea 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1807,6 +1807,15 @@ int ip6_append_data(struct sock *sk, } EXPORT_SYMBOL_GPL(ip6_append_data); +static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork) +{ + struct dst_entry *dst = cork->base.dst; + + cork->base.dst = NULL; + cork->base.flags &= ~IPCORK_ALLFRAG; + skb_dst_set(skb, dst); +} + static void ip6_cork_release(struct inet_cork_full *cork, struct inet6_cork *v6_cork) { @@ -1889,7 +1898,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk, skb->tstamp = cork->base.transmit_time; - skb_dst_set(skb, dst_clone(&rt->dst)); + ip6_cork_steal_dst(skb, cork); IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); if (proto == IPPROTO_ICMPV6) { struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |