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From: Martin KaFai Lau <kafai@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>,
	<netdev@vger.kernel.org>, Andrii Nakryiko <andrii@kernel.org>
Subject: [PATCH v2 bpf-next 13/14] bpf: selftests: bpf_cubic and bpf_dctcp calling kernel functions
Date: Wed, 24 Mar 2021 18:52:46 -0700	[thread overview]
Message-ID: <20210325015246.1551062-1-kafai@fb.com> (raw)
In-Reply-To: <20210325015124.1543397-1-kafai@fb.com>

This patch removes the bpf implementation of tcp_slow_start()
and tcp_cong_avoid_ai().  Instead, it directly uses the kernel
implementation.

It also replaces the bpf_cubic_undo_cwnd implementation by directly
calling tcp_reno_undo_cwnd().  bpf_dctcp also directly calls
tcp_reno_cong_avoid() instead.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 tools/testing/selftests/bpf/bpf_tcp_helpers.h | 29 ++-----------------
 tools/testing/selftests/bpf/progs/bpf_cubic.c |  6 ++--
 tools/testing/selftests/bpf/progs/bpf_dctcp.c | 22 ++++----------
 3 files changed, 11 insertions(+), 46 deletions(-)

diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index 91f0fac632f4..029589c008c9 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -187,16 +187,6 @@ struct tcp_congestion_ops {
 	typeof(y) __y = (y);			\
 	__x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
 
-static __always_inline __u32 tcp_slow_start(struct tcp_sock *tp, __u32 acked)
-{
-	__u32 cwnd = min(tp->snd_cwnd + acked, tp->snd_ssthresh);
-
-	acked -= cwnd - tp->snd_cwnd;
-	tp->snd_cwnd = min(cwnd, tp->snd_cwnd_clamp);
-
-	return acked;
-}
-
 static __always_inline bool tcp_in_slow_start(const struct tcp_sock *tp)
 {
 	return tp->snd_cwnd < tp->snd_ssthresh;
@@ -213,22 +203,7 @@ static __always_inline bool tcp_is_cwnd_limited(const struct sock *sk)
 	return !!BPF_CORE_READ_BITFIELD(tp, is_cwnd_limited);
 }
 
-static __always_inline void tcp_cong_avoid_ai(struct tcp_sock *tp, __u32 w, __u32 acked)
-{
-	/* If credits accumulated at a higher w, apply them gently now. */
-	if (tp->snd_cwnd_cnt >= w) {
-		tp->snd_cwnd_cnt = 0;
-		tp->snd_cwnd++;
-	}
-
-	tp->snd_cwnd_cnt += acked;
-	if (tp->snd_cwnd_cnt >= w) {
-		__u32 delta = tp->snd_cwnd_cnt / w;
-
-		tp->snd_cwnd_cnt -= delta * w;
-		tp->snd_cwnd += delta;
-	}
-	tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_cwnd_clamp);
-}
+extern __u32 tcp_slow_start(struct tcp_sock *tp, __u32 acked) __ksym;
+extern void tcp_cong_avoid_ai(struct tcp_sock *tp, __u32 w, __u32 acked) __ksym;
 
 #endif
diff --git a/tools/testing/selftests/bpf/progs/bpf_cubic.c b/tools/testing/selftests/bpf/progs/bpf_cubic.c
index 33c4d2bded64..f62df4d023f9 100644
--- a/tools/testing/selftests/bpf/progs/bpf_cubic.c
+++ b/tools/testing/selftests/bpf/progs/bpf_cubic.c
@@ -525,11 +525,11 @@ void BPF_STRUCT_OPS(bpf_cubic_acked, struct sock *sk,
 		hystart_update(sk, delay);
 }
 
+extern __u32 tcp_reno_undo_cwnd(struct sock *sk) __ksym;
+
 __u32 BPF_STRUCT_OPS(bpf_cubic_undo_cwnd, struct sock *sk)
 {
-	const struct tcp_sock *tp = tcp_sk(sk);
-
-	return max(tp->snd_cwnd, tp->prior_cwnd);
+	return tcp_reno_undo_cwnd(sk);
 }
 
 SEC(".struct_ops")
diff --git a/tools/testing/selftests/bpf/progs/bpf_dctcp.c b/tools/testing/selftests/bpf/progs/bpf_dctcp.c
index 4dc1a967776a..fd42247da8b4 100644
--- a/tools/testing/selftests/bpf/progs/bpf_dctcp.c
+++ b/tools/testing/selftests/bpf/progs/bpf_dctcp.c
@@ -194,22 +194,12 @@ __u32 BPF_PROG(dctcp_cwnd_undo, struct sock *sk)
 	return max(tcp_sk(sk)->snd_cwnd, ca->loss_cwnd);
 }
 
-SEC("struct_ops/tcp_reno_cong_avoid")
-void BPF_PROG(tcp_reno_cong_avoid, struct sock *sk, __u32 ack, __u32 acked)
-{
-	struct tcp_sock *tp = tcp_sk(sk);
-
-	if (!tcp_is_cwnd_limited(sk))
-		return;
+extern void tcp_reno_cong_avoid(struct sock *sk, __u32 ack, __u32 acked) __ksym;
 
-	/* In "safe" area, increase. */
-	if (tcp_in_slow_start(tp)) {
-		acked = tcp_slow_start(tp, acked);
-		if (!acked)
-			return;
-	}
-	/* In dangerous area, increase slowly. */
-	tcp_cong_avoid_ai(tp, tp->snd_cwnd, acked);
+SEC("struct_ops/dctcp_reno_cong_avoid")
+void BPF_PROG(dctcp_cong_avoid, struct sock *sk, __u32 ack, __u32 acked)
+{
+	tcp_reno_cong_avoid(sk, ack, acked);
 }
 
 SEC(".struct_ops")
@@ -226,7 +216,7 @@ struct tcp_congestion_ops dctcp = {
 	.in_ack_event   = (void *)dctcp_update_alpha,
 	.cwnd_event	= (void *)dctcp_cwnd_event,
 	.ssthresh	= (void *)dctcp_ssthresh,
-	.cong_avoid	= (void *)tcp_reno_cong_avoid,
+	.cong_avoid	= (void *)dctcp_cong_avoid,
 	.undo_cwnd	= (void *)dctcp_cwnd_undo,
 	.set_state	= (void *)dctcp_state,
 	.flags		= TCP_CONG_NEEDS_ECN,
-- 
2.30.2


  parent reply	other threads:[~2021-03-25  1:53 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-25  1:51 [PATCH v2 bpf-next 00/14] bpf: Support calling kernel function Martin KaFai Lau
2021-03-25  1:51 ` [PATCH v2 bpf-next 01/14] bpf: Simplify freeing logic in linfo and jited_linfo Martin KaFai Lau
2021-03-25  1:51 ` [PATCH v2 bpf-next 02/14] bpf: Refactor btf_check_func_arg_match Martin KaFai Lau
2021-03-25  1:51 ` [PATCH v2 bpf-next 03/14] bpf: Support bpf program calling kernel function Martin KaFai Lau
2021-03-25 22:02   ` Toke Høiland-Jørgensen
2021-03-25 23:09     ` Martin KaFai Lau
2021-03-26 10:11       ` Toke Høiland-Jørgensen
2021-03-26 14:20         ` Alexei Starovoitov
2021-03-26 15:14           ` Toke Høiland-Jørgensen
2021-03-27  3:59   ` Alexei Starovoitov
2021-03-25  1:51 ` [PATCH v2 bpf-next 04/14] bpf: Support kernel function call in x86-32 Martin KaFai Lau
2021-03-25  1:51 ` [PATCH v2 bpf-next 05/14] tcp: Rename bictcp function prefix to cubictcp Martin KaFai Lau
2021-03-25  1:52 ` [PATCH v2 bpf-next 06/14] bpf: tcp: Put some tcp cong functions in allowlist for bpf-tcp-cc Martin KaFai Lau
2021-03-25  1:52 ` [PATCH v2 bpf-next 07/14] libbpf: Refactor bpf_object__resolve_ksyms_btf_id Martin KaFai Lau
2021-03-25  1:52 ` [PATCH v2 bpf-next 08/14] libbpf: Refactor codes for finding btf id of a kernel symbol Martin KaFai Lau
2021-03-25  1:52 ` [PATCH v2 bpf-next 09/14] libbpf: Rename RELO_EXTERN to RELO_EXTERN_VAR Martin KaFai Lau
2021-03-25  1:52 ` [PATCH v2 bpf-next 10/14] libbpf: Record extern sym relocation first Martin KaFai Lau
2021-03-25  1:52 ` [PATCH v2 bpf-next 11/14] libbpf: Support extern kernel function Martin KaFai Lau
2021-03-25  1:52 ` [PATCH v2 bpf-next 12/14] bpf: selftests: Rename bictcp to bpf_cubic Martin KaFai Lau
2021-03-25  1:52 ` Martin KaFai Lau [this message]
2021-03-25  1:52 ` [PATCH v2 bpf-next 14/14] bpf: selftests: Add kfunc_call test Martin KaFai Lau
2021-03-27  3:50 ` [PATCH v2 bpf-next 00/14] bpf: Support calling kernel function patchwork-bot+netdevbpf
2021-03-27 21:25 ` Cong Wang
2021-03-27 21:28   ` Alexei Starovoitov
2021-03-27 22:07     ` Cong Wang
2021-03-27 22:53       ` Alexei Starovoitov
2021-03-28 20:13         ` Cong Wang
2021-03-29  1:24           ` Martin KaFai Lau
2021-03-29 16:06             ` Lorenz Bauer
2021-03-29 19:08               ` Martin KaFai Lau
2021-03-31  6:44                 ` Andrii Nakryiko
2021-04-01 19:51                   ` Martin KaFai Lau
2021-04-01 19:52                     ` Andrii Nakryiko
2021-03-29 20:18             ` Cong Wang
2021-03-30  9:43 ` Lorenz Bauer
2021-03-30 14:35   ` Alexei Starovoitov
2021-03-30 19:58     ` Cong Wang
2021-03-30 21:43       ` Martin KaFai Lau
2021-03-31  3:28         ` [External] " Jiang Wang .
2021-03-31  4:55           ` Martin KaFai Lau

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