From 4acb41903b2f99f3dffd4c3df9acc84ca5942cb2 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Mon, 30 Jan 2012 01:20:17 +0000 Subject: net/tcp: Fix tcp memory limits initialization when !CONFIG_SYSCTL sysctl_tcp_mem() initialization was moved to sysctl_tcp_ipv4.c in commit 3dc43e3e4d0b52197d3205214fe8f162f9e0c334, since it became a per-ns value. That code, however, will never run when CONFIG_SYSCTL is disabled, leading to bogus values on those fields - causing hung TCP sockets. This patch fixes it by keeping an initialization code in tcp_init(). It will be overwritten by the first net namespace init if CONFIG_SYSCTL is compiled in, and do the right thing if it is compiled out. It is also named properly as tcp_init_mem(), to properly signal its non-sysctl side effect on TCP limits. Reported-by: Ingo Molnar Signed-off-by: Glauber Costa Cc: David S. Miller Link: http://lkml.kernel.org/r/4F22D05A.8030604@parallels.com [ renamed the function, tidied up the changelog a bit ] Signed-off-by: Ingo Molnar Signed-off-by: David S. Miller --- net/ipv4/sysctl_net_ipv4.c | 1 + net/ipv4/tcp.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 4aa7e9dc0cbb..4cb9cd2f2c39 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -814,6 +814,7 @@ 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; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 9bcdec3ad772..06373b4a449a 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3216,6 +3216,16 @@ static int __init set_thash_entries(char *str) } __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; + net->ipv4.sysctl_tcp_mem[1] = limit; + net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2; +} + void __init tcp_init(void) { struct sk_buff *skb = NULL; @@ -3276,9 +3286,9 @@ void __init tcp_init(void) sysctl_tcp_max_orphans = cnt / 2; sysctl_max_syn_backlog = max(128, cnt / 256); - /* Set per-socket limits to no more than 1/128 the pressure threshold */ - limit = ((unsigned long)init_net.ipv4.sysctl_tcp_mem[1]) - << (PAGE_SHIFT - 7); + tcp_init_mem(&init_net); + limit = nr_free_buffer_pages() / 8; + limit = max(limit, 128UL); max_share = min(4UL*1024*1024, limit); sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; -- cgit v1.2.1