netdev - [PATCH v2 2/2] sctp: optimize the sctp_sysctl_net

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Date:	Tue, 11 Feb 2014 09:49:06 +0800
From:	Wang Weidong <wangweidong1@...wei.com>
To:	<nhorman@...driver.com>, <davem@...emloft.net>,
	<vyasevich@...il.com>
CC:	<dborkman@...hat.com>, <netdev@...r.kernel.org>
Subject: [PATCH v2 2/2] sctp: optimize the sctp_sysctl_net_register

Here, when the net is init_net, we needn't to kmemdup the ctl_table
again. So add a check for net. Also we can save some memory.

Signed-off-by: Wang Weidong <wangweidong1@...wei.com>
---
 net/sctp/sysctl.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index 2ddb401..b65396b 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -403,15 +403,17 @@ static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
 
 int sctp_sysctl_net_register(struct net *net)
 {
-	struct ctl_table *table;
-	int i;
+	struct ctl_table *table = sctp_net_table;
 
-	table = kmemdup(sctp_net_table, sizeof(sctp_net_table), GFP_KERNEL);
-	if (!table)
-		return -ENOMEM;
+	if (!net_eq(net, &init_net)) {
+		int i;
+		table = kmemdup(sctp_net_table, sizeof(sctp_net_table), GFP_KERNEL);
+		if (!table)
+			return -ENOMEM;
 
-	for (i = 0; table[i].data; i++)
-		table[i].data += (char *)(&net->sctp) - (char *)&init_net.sctp;
+		for (i = 0; table[i].data; i++)
+			table[i].data += (char *)(&net->sctp) - (char *)&init_net.sctp;
+	}
 
 	net->sctp.sysctl_header = register_net_sysctl(net, "net/sctp", table);
 	return 0;
-- 
1.7.12


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