From: Yafang Shao <laoar.shao@gmail.com>
To: edumazet@google.com, davem@davemloft.net
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH net-next] tcp: remove useless add operation when init sysctl_max_tw_buckets
Date: Sat, 1 Sep 2018 20:21:05 +0800 [thread overview]
Message-ID: <1535804465-11795-2-git-send-email-laoar.shao@gmail.com> (raw)
In-Reply-To: <1535804465-11795-1-git-send-email-laoar.shao@gmail.com>
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 <laoar.shao@gmail.com>
---
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
next prev parent reply other threads:[~2018-09-01 12:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-01 12:21 [PATCH net-next v3] tcp: propagate gso_segs to the new skb built in tcp collapse Yafang Shao
2018-09-01 12:21 ` Yafang Shao [this message]
2018-09-02 23:13 ` [PATCH net-next] tcp: remove useless add operation when init sysctl_max_tw_buckets David Miller
2018-09-02 20:34 ` [PATCH net-next v3] tcp: propagate gso_segs to the new skb built in tcp collapse Eric Dumazet
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