From: Joe Stringer <joe@wand.net.nz>
To: Martin KaFai Lau <kafai@fb.com>
Cc: Joe Stringer <joe@wand.net.nz>,
bpf@vger.kernel.org, netdev <netdev@vger.kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Lorenz Bauer <lmb@cloudflare.com>
Subject: Re: [PATCH bpf-next 4/7] dst: Prefetch established socket destinations
Date: Mon, 16 Mar 2020 20:17:59 -0700 [thread overview]
Message-ID: <CAOftzPjMO2Y=efeqYZCzYd2JX8JZULfvCNw2mc-io1anxNYgGA@mail.gmail.com> (raw)
In-Reply-To: <20200316230312.oxgsjpyzhp5iiyyx@kafai-mbp>
On Mon, Mar 16, 2020 at 4:03 PM Martin KaFai Lau <kafai@fb.com> wrote:
>
> On Thu, Mar 12, 2020 at 04:36:45PM -0700, Joe Stringer wrote:
> > Enhance the dst_sk_prefetch logic to temporarily store the socket
> > receive destination, to save the route lookup later on. The dst
> > reference is kept alive by the caller's socket reference.
> >
> > Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
> > Signed-off-by: Joe Stringer <joe@wand.net.nz>
> > ---
> > include/net/dst_metadata.h | 2 +-
> > net/core/dst.c | 20 +++++++++++++++++---
> > net/core/filter.c | 2 +-
> > 3 files changed, 19 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h
> > index 31574c553a07..4f16322b08d5 100644
> > --- a/include/net/dst_metadata.h
> > +++ b/include/net/dst_metadata.h
> > @@ -230,7 +230,7 @@ static inline bool skb_dst_is_sk_prefetch(const struct sk_buff *skb)
> > return dst_is_sk_prefetch(skb_dst(skb));
> > }
> >
> > -void dst_sk_prefetch_store(struct sk_buff *skb);
> > +void dst_sk_prefetch_store(struct sk_buff *skb, struct sock *sk);
> > void dst_sk_prefetch_fetch(struct sk_buff *skb);
> >
> > /**
> > diff --git a/net/core/dst.c b/net/core/dst.c
> > index cf1a1d5b6b0a..5068d127d9c2 100644
> > --- a/net/core/dst.c
> > +++ b/net/core/dst.c
> > @@ -346,11 +346,25 @@ EXPORT_SYMBOL(dst_sk_prefetch);
> >
> > DEFINE_PER_CPU(unsigned long, dst_sk_prefetch_dst);
> >
> > -void dst_sk_prefetch_store(struct sk_buff *skb)
> > +void dst_sk_prefetch_store(struct sk_buff *skb, struct sock *sk)
> > {
> > - unsigned long refdst;
> > + unsigned long refdst = 0L;
> > +
> > + WARN_ON(!rcu_read_lock_held() &&
> > + !rcu_read_lock_bh_held());
> > + if (sk_fullsock(sk)) {
> > + struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
> > +
> > + if (dst)
> > + dst = dst_check(dst, 0);
> v6 requires a cookie. tcp_v6_early_demux() could be a good example.
Nice catch. I plan to roll in the following incremental for v2:
diff --git a/net/core/dst.c b/net/core/dst.c
index 5068d127d9c2..b60f85227247 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -354,9 +354,14 @@ void dst_sk_prefetch_store(struct sk_buff *skb,
struct sock *sk)
!rcu_read_lock_bh_held());
if (sk_fullsock(sk)) {
struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
+ u32 cookie = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+ if (sk->sk_family == AF_INET6)
+ cookie = inet6_sk(sk)->rx_dst_cookie;
+#endif
if (dst)
- dst = dst_check(dst, 0);
+ dst = dst_check(dst, cookie);
if (dst)
refdst = (unsigned long)dst | SKB_DST_NOREF;
}
next prev parent reply other threads:[~2020-03-17 3:18 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 23:36 [PATCH bpf-next 0/7] Add bpf_sk_assign eBPF helper Joe Stringer
2020-03-12 23:36 ` [PATCH bpf-next 1/7] dst: Move skb_dst_drop to skbuff.c Joe Stringer
2020-03-12 23:36 ` [PATCH bpf-next 2/7] dst: Add socket prefetch metadata destinations Joe Stringer
2020-03-12 23:36 ` [PATCH bpf-next 3/7] bpf: Add socket assign support Joe Stringer
2020-03-16 10:08 ` Jakub Sitnicki
2020-03-16 21:23 ` Joe Stringer
2020-03-16 22:57 ` Martin KaFai Lau
2020-03-17 3:06 ` Joe Stringer
2020-03-17 6:26 ` Martin KaFai Lau
2020-03-18 0:46 ` Joe Stringer
2020-03-18 10:03 ` Jakub Sitnicki
2020-03-19 5:49 ` Joe Stringer
2020-03-18 18:48 ` Martin KaFai Lau
2020-03-19 6:24 ` Joe Stringer
2020-03-20 1:54 ` Martin KaFai Lau
2020-03-20 4:28 ` Joe Stringer
2020-03-17 10:09 ` Lorenz Bauer
2020-03-18 1:10 ` Joe Stringer
2020-03-18 2:03 ` Joe Stringer
2020-03-12 23:36 ` [PATCH bpf-next 4/7] dst: Prefetch established socket destinations Joe Stringer
2020-03-16 23:03 ` Martin KaFai Lau
2020-03-17 3:17 ` Joe Stringer [this message]
2020-03-12 23:36 ` [PATCH bpf-next 5/7] selftests: bpf: add test for sk_assign Joe Stringer
2020-03-17 6:30 ` Martin KaFai Lau
2020-03-17 20:56 ` Joe Stringer
2020-03-18 17:27 ` Martin KaFai Lau
2020-03-19 5:45 ` Joe Stringer
2020-03-19 17:36 ` Andrii Nakryiko
2020-03-12 23:36 ` [PATCH bpf-next 6/7] selftests: bpf: Extend sk_assign for address proxy Joe Stringer
2020-03-12 23:36 ` [PATCH bpf-next 7/7] selftests: bpf: Improve debuggability of sk_assign Joe Stringer
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