diff mbox series

[net-next] net/tcp_fastopen: remove tcp_fastopen_ctx_lock

Message ID 20210719101107.3203943-1-eric.dumazet@gmail.com
State New
Headers show
Series [net-next] net/tcp_fastopen: remove tcp_fastopen_ctx_lock | expand

Commit Message

Eric Dumazet July 19, 2021, 10:11 a.m. UTC 
From: Eric Dumazet <edumazet@google.com>

Remove the (per netns) spinlock in favor of xchg() atomic operations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
---
 include/net/netns/ipv4.h |  1 -
 net/ipv4/tcp_fastopen.c  | 17 +++--------------
 net/ipv4/tcp_ipv4.c      |  1 -
 3 files changed, 3 insertions(+), 16 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org July 20, 2021, 11:30 a.m. UTC | #1 
Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Mon, 19 Jul 2021 03:11:07 -0700 you wrote:
> From: Eric Dumazet <edumazet@google.com>
> 
> Remove the (per netns) spinlock in favor of xchg() atomic operations.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Wei Wang <weiwan@google.com>
> Cc: Yuchung Cheng <ycheng@google.com>
> Cc: Neal Cardwell <ncardwell@google.com>
> 
> [...]

Here is the summary with links:
  - [net-next] net/tcp_fastopen: remove tcp_fastopen_ctx_lock
    https://git.kernel.org/netdev/net-next/c/e93abb840a2c

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index b8620519eace8191c76c41f37bd51ac0d3788bc2..2f65701a43c953bd3a9a9e3d491882cb7bb11859 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -174,7 +174,6 @@  struct netns_ipv4 {
 	int sysctl_tcp_fastopen;
 	const struct tcp_congestion_ops __rcu  *tcp_congestion_control;
 	struct tcp_fastopen_context __rcu *tcp_fastopen_ctx;
-	spinlock_t tcp_fastopen_ctx_lock;
 	unsigned int sysctl_tcp_fastopen_blackhole_timeout;
 	atomic_t tfo_active_disable_times;
 	unsigned long tfo_active_disable_stamp;
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index 47c32604d38fca960d2cd56f3588bfd2e390b789..1a9fbd5448a719bb5407a8d1e8fbfbe54f56f258 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -55,12 +55,7 @@  void tcp_fastopen_ctx_destroy(struct net *net)
 {
 	struct tcp_fastopen_context *ctxt;
 
-	spin_lock(&net->ipv4.tcp_fastopen_ctx_lock);
-
-	ctxt = rcu_dereference_protected(net->ipv4.tcp_fastopen_ctx,
-				lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));
-	rcu_assign_pointer(net->ipv4.tcp_fastopen_ctx, NULL);
-	spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock);
+	ctxt = xchg((__force struct tcp_fastopen_context **)&net->ipv4.tcp_fastopen_ctx, NULL);
 
 	if (ctxt)
 		call_rcu(&ctxt->rcu, tcp_fastopen_ctx_free);
@@ -89,18 +84,12 @@  int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk,
 		ctx->num = 1;
 	}
 
-	spin_lock(&net->ipv4.tcp_fastopen_ctx_lock);
 	if (sk) {
 		q = &inet_csk(sk)->icsk_accept_queue.fastopenq;
-		octx = rcu_dereference_protected(q->ctx,
-			lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));
-		rcu_assign_pointer(q->ctx, ctx);
+		octx = xchg((__force struct tcp_fastopen_context **)&q->ctx, ctx);
 	} else {
-		octx = rcu_dereference_protected(net->ipv4.tcp_fastopen_ctx,
-			lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));
-		rcu_assign_pointer(net->ipv4.tcp_fastopen_ctx, ctx);
+		octx = xchg((__force struct tcp_fastopen_context **)&net->ipv4.tcp_fastopen_ctx, ctx);
 	}
-	spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock);
 
 	if (octx)
 		call_rcu(&octx->rcu, tcp_fastopen_ctx_free);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index b9dc2d6197be8b8b03a4d052ad1c87987c7a62aa..e9321dd39cdbcb664843d4ada09a21685b93abb7 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2964,7 +2964,6 @@  static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_comp_sack_slack_ns = 100 * NSEC_PER_USEC;
 	net->ipv4.sysctl_tcp_comp_sack_nr = 44;
 	net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
-	spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);
 	net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 60 * 60;
 	atomic_set(&net->ipv4.tfo_active_disable_times, 0);