From: Stanislav Fomichev <sdf@google.com>
To: netdev@vger.kernel.org, bpf@vger.kernel.org
Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net,
Stanislav Fomichev <sdf@google.com>,
Eric Dumazet <edumazet@google.com>,
Priyaranjan Jha <priyarjha@google.com>,
Yuchung Cheng <ycheng@google.com>,
Soheil Hassas Yeganeh <soheil@google.com>
Subject: [PATCH bpf-next 1/8] bpf: add BPF_CGROUP_SOCK_OPS callback that is executed on every RTT
Date: Mon, 1 Jul 2019 13:48:14 -0700 [thread overview]
Message-ID: <20190701204821.44230-2-sdf@google.com> (raw)
In-Reply-To: <20190701204821.44230-1-sdf@google.com>
Performance impact should be minimal because it's under a new
BPF_SOCK_OPS_RTT_CB_FLAG flag that has to be explicitly enabled.
Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Priyaranjan Jha <priyarjha@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
include/net/tcp.h | 8 ++++++++
include/uapi/linux/bpf.h | 6 +++++-
net/ipv4/tcp_input.c | 4 ++++
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9d36cc88d043..e16d8a3fd3b4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2221,6 +2221,14 @@ static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk)
return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1);
}
+static inline void tcp_bpf_rtt(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RTT_CB_FLAG))
+ tcp_call_bpf(sk, BPF_SOCK_OPS_RTT_CB, 0, NULL);
+}
+
#if IS_ENABLED(CONFIG_SMC)
extern struct static_key_false tcp_have_smc;
#endif
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index cffea1826a1f..9cdd0aaeba06 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1770,6 +1770,7 @@ union bpf_attr {
* * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
* * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
* * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
+ * * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT)
*
* Therefore, this function can be used to clear a callback flag by
* setting the appropriate bit to zero. e.g. to disable the RTO
@@ -3314,7 +3315,8 @@ struct bpf_sock_ops {
#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0)
#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1)
#define BPF_SOCK_OPS_STATE_CB_FLAG (1<<2)
-#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x7 /* Mask of all currently
+#define BPF_SOCK_OPS_RTT_CB_FLAG (1<<3)
+#define BPF_SOCK_OPS_ALL_CB_FLAGS 0xF /* Mask of all currently
* supported cb flags
*/
@@ -3369,6 +3371,8 @@ enum {
BPF_SOCK_OPS_TCP_LISTEN_CB, /* Called on listen(2), right after
* socket transition to LISTEN state.
*/
+ BPF_SOCK_OPS_RTT_CB, /* Called on every RTT.
+ */
};
/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b71efeb0ae5b..c21e8a22fb3b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -778,6 +778,8 @@ static void tcp_rtt_estimator(struct sock *sk, long mrtt_us)
tp->rttvar_us -= (tp->rttvar_us - tp->mdev_max_us) >> 2;
tp->rtt_seq = tp->snd_nxt;
tp->mdev_max_us = tcp_rto_min_us(sk);
+
+ tcp_bpf_rtt(sk);
}
} else {
/* no previous measure. */
@@ -786,6 +788,8 @@ static void tcp_rtt_estimator(struct sock *sk, long mrtt_us)
tp->rttvar_us = max(tp->mdev_us, tcp_rto_min_us(sk));
tp->mdev_max_us = tp->rttvar_us;
tp->rtt_seq = tp->snd_nxt;
+
+ tcp_bpf_rtt(sk);
}
tp->srtt_us = max(1U, srtt);
}
--
2.22.0.410.gd8fdbe21b5-goog
next prev parent reply other threads:[~2019-07-01 20:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-01 20:48 [PATCH bpf-next 0/8] bpf: TCP RTT sock_ops bpf callback Stanislav Fomichev
2019-07-01 20:48 ` Stanislav Fomichev [this message]
2019-07-01 20:48 ` [PATCH bpf-next 2/8] bpf: split shared bpf_tcp_sock and bpf_sock_ops implementation Stanislav Fomichev
2019-07-01 20:48 ` [PATCH bpf-next 3/8] bpf: add dsack_dups/delivered{,_ce} to bpf_tcp_sock Stanislav Fomichev
2019-07-01 20:48 ` [PATCH bpf-next 4/8] bpf: add icsk_retransmits " Stanislav Fomichev
2019-07-01 20:48 ` [PATCH bpf-next 5/8] bpf/tools: sync bpf.h Stanislav Fomichev
2019-07-01 20:48 ` [PATCH bpf-next 6/8] selftests/bpf: test BPF_SOCK_OPS_RTT_CB Stanislav Fomichev
2019-07-01 23:40 ` Y Song
2019-07-02 0:07 ` Stanislav Fomichev
2019-07-02 0:26 ` Y Song
2019-07-01 20:48 ` [PATCH bpf-next 7/8] samples/bpf: add sample program that periodically dumps TCP stats Stanislav Fomichev
2019-07-02 0:15 ` Y Song
2019-07-02 0:31 ` Stanislav Fomichev
2019-07-02 0:39 ` Y Song
2019-07-01 20:48 ` [PATCH bpf-next 8/8] samples/bpf: fix tcp_bpf.readme detach command Stanislav Fomichev
2019-07-01 21:03 ` [PATCH bpf-next 0/8] bpf: TCP RTT sock_ops bpf callback Soheil Hassas Yeganeh
2019-07-01 21:15 ` Yuchung Cheng
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