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

   1 From 804fbb3f2ec9283f7b778e057a68bfff440a0be6 Mon Sep 17 00:00:00 2001
   2 From: Rui Salvaterra <rsalvaterra@gmail.com>
   3 Date: Wed, 30 Mar 2022 22:51:55 +0100
   4 Subject: [PATCH] kernel: ct: size the hashtable more adequately
   5
   6 To set the default size of the connection tracking hash table, a divider of
   7 16384 becomes inadequate for a router handling lots of connections. Divide by
   8 2048 instead, making the default size scale better with the available RAM.
   9
  10 Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
  11 ---
  12  net/netfilter/nf_conntrack_core.c | 2 +-
  13  1 file changed, 1 insertion(+), 1 deletion(-)
  14
  15 --- a/net/netfilter/nf_conntrack_core.c
  16 +++ b/net/netfilter/nf_conntrack_core.c
  17 @@ -2727,7 +2727,7 @@ int nf_conntrack_init_start(void)
  18
  19         if (!nf_conntrack_htable_size) {
  20                 nf_conntrack_htable_size
  21 -                       = (((nr_pages << PAGE_SHIFT) / 16384)
  22 +                       = (((nr_pages << PAGE_SHIFT) / 2048)
  23                            / sizeof(struct hlist_head));
  24                 if (BITS_PER_LONG >= 64 &&
  25                     nr_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))