openwrt/target/linux/generic/hack-5.15/661-kernel-ct-size-the-hashtable-more-adequately.patch

From 804fbb3f2ec9283f7b778e057a68bfff440a0be6 Mon Sep 17 00:00:00 2001
From: Rui Salvaterra <rsalvaterra@gmail.com>
Date: Wed, 30 Mar 2022 22:51:55 +0100
Subject: [PATCH] kernel: ct: size the hashtable more adequately

To set the default size of the connection tracking hash table, a divider of
16384 becomes inadequate for a router handling lots of connections. Divide by
2048 instead, making the default size scale better with the available RAM.

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
---
 net/netfilter/nf_conntrack_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -2738,7 +2738,7 @@ int nf_conntrack_init_start(void)
 
 	if (!nf_conntrack_htable_size) {
 		nf_conntrack_htable_size
-			= (((nr_pages << PAGE_SHIFT) / 16384)
+			= (((nr_pages << PAGE_SHIFT) / 2048)
 			   / sizeof(struct hlist_head));
 		if (BITS_PER_LONG >= 64 &&
 		    nr_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))