tcp: remove sk_{tr}x_skb_cache

This reverts the following patches :

- commit 2e05fcae83c4 ("tcp: fix compile error if !CONFIG_SYSCTL")
- commit 4f661542a402 ("tcp: fix zerocopy and notsent_lowat issues")
- commit 472c2e07eef0 ("tcp: add one skb cache for tx")
- commit 8b27dae5a2e8 ("tcp: add one skb cache for rx")

Having a cache of one skb (in each direction) per TCP socket is fragile,
since it can cause a significant increase of memory needs,
and not good enough for high speed flows anyway where more than one skb
is needed.

We want instead to add a generic infrastructure, with more flexible
per-cpu caches, for alien NUMA nodes.

Acked-by: Paolo Abeni <[email protected]>
Acked-by: Mat Martineau <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

1 files changed, 0 insertions, 12 deletions

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 4680268f2e59..97eb54774924 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -585,18 +585,6 @@ static struct ctl_table ipv4_table[] = {
 		.extra1		= &sysctl_fib_sync_mem_min,
 		.extra2		= &sysctl_fib_sync_mem_max,
 	},
-	{
-		.procname	= "tcp_rx_skb_cache",
-		.data		= &tcp_rx_skb_cache_key.key,
-		.mode		= 0644,
-		.proc_handler	= proc_do_static_key,
-	},
-	{
-		.procname	= "tcp_tx_skb_cache",
-		.data		= &tcp_tx_skb_cache_key.key,
-		.mode		= 0644,
-		.proc_handler	= proc_do_static_key,
-	},
 	{ }
 };