From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yafang Shao Subject: [PATCH net-next] tcp: remove useless add operation when init sysctl_max_tw_buckets Date: Sat, 1 Sep 2018 20:21:05 +0800 Message-ID: <1535804465-11795-2-git-send-email-laoar.shao@gmail.com> References: <1535804465-11795-1-git-send-email-laoar.shao@gmail.com> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Yafang Shao To: edumazet@google.com, davem@davemloft.net Return-path: In-Reply-To: <1535804465-11795-1-git-send-email-laoar.shao@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org cp_hashinfo.ehash_mask is always an odd number, which is set in function alloc_large_system_hash(). See bellow, if (_hash_mask) *_hash_mask = (1 << log2qty) - 1; <<< always odd number Hence the local variable 'cnt' is a even number, as a result of that it is no difference to do the incrementation here. Signed-off-by: Yafang Shao --- net/ipv4/tcp_ipv4.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 44c09ed..09547ef 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2549,7 +2549,7 @@ static int __net_init tcp_sk_init(struct net *net) net->ipv4.sysctl_tcp_tw_reuse = 2; cnt = tcp_hashinfo.ehash_mask + 1; - net->ipv4.tcp_death_row.sysctl_max_tw_buckets = (cnt + 1) / 2; + net->ipv4.tcp_death_row.sysctl_max_tw_buckets = cnt / 2; net->ipv4.tcp_death_row.hashinfo = &tcp_hashinfo; net->ipv4.sysctl_max_syn_backlog = max(128, cnt / 256); -- 1.8.3.1