tcp: properly initialize tcp memory limits

Commit 4acb419 tries to fix the using uninitialized value introduced by commit 3dc43e3, but it would make the per-socket memory limits too small. This patch fixes this and also remove the redundant codes introduced in 4acb419. Signed-off-by: Jason Wang <[email protected]> Acked-by: Glauber Costa <[email protected]> Signed-off-by: David S. Miller <[email protected]>
mrcsosa · Feb 2, 2012 · c43b874 · c43b874
1 parent 786f528
commit c43b874
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Showing 2 changed files with 2 additions and 8 deletions.
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
@@ -778,7 +778,6 @@ EXPORT_SYMBOL_GPL(net_ipv4_ctl_path);
 static __net_init int ipv4_sysctl_init_net(struct net *net)
 {
 	struct ctl_table *table;
-	unsigned long limit;
 
 	table = ipv4_net_table;
 	if (!net_eq(net, &init_net)) {
@@ -815,11 +814,6 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 	net->ipv4.sysctl_rt_cache_rebuild_count = 4;
 
 	tcp_init_mem(net);
-	limit = nr_free_buffer_pages() / 8;
-	limit = max(limit, 128UL);
-	net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3;
-	net->ipv4.sysctl_tcp_mem[1] = limit;
-	net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2;
 
 	net->ipv4.ipv4_hdr = register_net_sysctl_table(net,
 			net_ipv4_ctl_path, table);

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
@@ -3229,7 +3229,6 @@ __setup("thash_entries=", set_thash_entries);
 
 void tcp_init_mem(struct net *net)
 {
-	/* Set per-socket limits to no more than 1/128 the pressure threshold */
 	unsigned long limit = nr_free_buffer_pages() / 8;
 	limit = max(limit, 128UL);
 	net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3;
@@ -3298,7 +3297,8 @@ void __init tcp_init(void)
 	sysctl_max_syn_backlog = max(128, cnt / 256);
 
 	tcp_init_mem(&init_net);
-	limit = nr_free_buffer_pages() / 8;
+	/* Set per-socket limits to no more than 1/128 the pressure threshold */
+	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 10);
 	limit = max(limit, 128UL);
 	max_share = min(4UL*1024*1024, limit);