per-netns ipv4 sysctl_tcp_mem

This patch allows each namespace to independently set up
its levels for tcp memory pressure thresholds. This patch
alone does not buy much: we need to make this values
per group of process somehow. This is achieved in the
patches that follows in this patchset.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: David S. Miller <davem@davemloft.net>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index d786b4f..bbd023a 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -55,6 +55,7 @@ struct netns_ipv4 {
        int current_rt_cache_rebuild_count;
 
        unsigned int sysctl_ping_group_range[2];
+       long sysctl_tcp_mem[3];
 
        atomic_t rt_genid;
        atomic_t dev_addr_genid;

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 913473b..a4f52e1 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -230,7 +230,6 @@ extern int sysctl_tcp_fack;
 extern int sysctl_tcp_reordering;
 extern int sysctl_tcp_ecn;
 extern int sysctl_tcp_dsack;
-extern long sysctl_tcp_mem[3];
 extern int sysctl_tcp_wmem[3];
 extern int sysctl_tcp_rmem[3];
 extern int sysctl_tcp_app_win;

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 15dc4c4..f7b5670 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1672,6 +1672,8 @@ static int __init inet_init(void)
        ip_static_sysctl_init();
 #endif
 
+       tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
+
        /*
         *      Add all the base protocols.
         */

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 69fd720..bbd67ab 100644 (file)
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/nsproxy.h>
+#include <linux/swap.h>
 #include <net/snmp.h>
 #include <net/icmp.h>
 #include <net/ip.h>
@@ -174,6 +175,36 @@ static int proc_allowed_congestion_control(ctl_table *ctl,
        return ret;
 }
 
+static int ipv4_tcp_mem(ctl_table *ctl, int write,
+                          void __user *buffer, size_t *lenp,
+                          loff_t *ppos)
+{
+       int ret;
+       unsigned long vec[3];
+       struct net *net = current->nsproxy->net_ns;
+
+       ctl_table tmp = {
+               .data = &vec,
+               .maxlen = sizeof(vec),
+               .mode = ctl->mode,
+       };
+
+       if (!write) {
+               ctl->data = &net->ipv4.sysctl_tcp_mem;
+               return proc_doulongvec_minmax(ctl, write, buffer, lenp, ppos);
+       }
+
+       ret = proc_doulongvec_minmax(&tmp, write, buffer, lenp, ppos);
+       if (ret)
+               return ret;
+
+       net->ipv4.sysctl_tcp_mem[0] = vec[0];
+       net->ipv4.sysctl_tcp_mem[1] = vec[1];
+       net->ipv4.sysctl_tcp_mem[2] = vec[2];
+
+       return 0;
+}
+
 static struct ctl_table ipv4_table[] = {
        {
                .procname       = "tcp_timestamps",
@@ -433,13 +464,6 @@ static struct ctl_table ipv4_table[] = {
                .proc_handler   = proc_dointvec
        },
        {
-               .procname       = "tcp_mem",
-               .data           = &sysctl_tcp_mem,
-               .maxlen         = sizeof(sysctl_tcp_mem),
-               .mode           = 0644,
-               .proc_handler   = proc_doulongvec_minmax
-       },
-       {
                .procname       = "tcp_wmem",
                .data           = &sysctl_tcp_wmem,
                .maxlen         = sizeof(sysctl_tcp_wmem),
@@ -721,6 +745,12 @@ static struct ctl_table ipv4_net_table[] = {
                .mode           = 0644,
                .proc_handler   = ipv4_ping_group_range,
        },
+       {
+               .procname       = "tcp_mem",
+               .maxlen         = sizeof(init_net.ipv4.sysctl_tcp_mem),
+               .mode           = 0644,
+               .proc_handler   = ipv4_tcp_mem,
+       },
        { }
 };
 
@@ -734,6 +764,7 @@ 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)) {
@@ -769,6 +800,12 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 
        net->ipv4.sysctl_rt_cache_rebuild_count = 4;
 
+       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);
        if (net->ipv4.ipv4_hdr == NULL)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 43dfccc..9bcdec3 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -282,11 +282,9 @@ int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
 struct percpu_counter tcp_orphan_count;
 EXPORT_SYMBOL_GPL(tcp_orphan_count);
 
-long sysctl_tcp_mem[3] __read_mostly;
 int sysctl_tcp_wmem[3] __read_mostly;
 int sysctl_tcp_rmem[3] __read_mostly;
 
-EXPORT_SYMBOL(sysctl_tcp_mem);
 EXPORT_SYMBOL(sysctl_tcp_rmem);
 EXPORT_SYMBOL(sysctl_tcp_wmem);
 
@@ -3278,14 +3276,9 @@ void __init tcp_init(void)
        sysctl_tcp_max_orphans = cnt / 2;
        sysctl_max_syn_backlog = max(128, cnt / 256);
 
-       limit = nr_free_buffer_pages() / 8;
-       limit = max(limit, 128UL);
-       sysctl_tcp_mem[0] = limit / 4 * 3;
-       sysctl_tcp_mem[1] = limit;
-       sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
-
        /* Set per-socket limits to no more than 1/128 the pressure threshold */
-       limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
+       limit = ((unsigned long)init_net.ipv4.sysctl_tcp_mem[1])
+               << (PAGE_SHIFT - 7);
        max_share = min(4UL*1024*1024, limit);
 
        sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 42714cb..1eb4ad5 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2623,7 +2623,6 @@ struct proto tcp_prot = {
        .orphan_count           = &tcp_orphan_count,
        .memory_allocated       = &tcp_memory_allocated,
        .memory_pressure        = &tcp_memory_pressure,
-       .sysctl_mem             = sysctl_tcp_mem,
        .sysctl_wmem            = sysctl_tcp_wmem,
        .sysctl_rmem            = sysctl_tcp_rmem,
        .max_header             = MAX_TCP_HEADER,

diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
index 4a68d2c..bfb0c2b 100644 (file)
--- a/net/ipv4/tcp_memcontrol.c
+++ b/net/ipv4/tcp_memcontrol.c
@@ -1,6 +1,8 @@
 #include <net/tcp.h>
 #include <net/tcp_memcontrol.h>
 #include <net/sock.h>
+#include <net/ip.h>
+#include <linux/nsproxy.h>
 #include <linux/memcontrol.h>
 #include <linux/module.h>
 
@@ -28,6 +30,7 @@ int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
        struct tcp_memcontrol *tcp;
        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
        struct mem_cgroup *parent = parent_mem_cgroup(memcg);
+       struct net *net = current->nsproxy->net_ns;
 
        cg_proto = tcp_prot.proto_cgroup(memcg);
        if (!cg_proto)
@@ -35,9 +38,9 @@ int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
 
        tcp = tcp_from_cgproto(cg_proto);
 
-       tcp->tcp_prot_mem[0] = sysctl_tcp_mem[0];
-       tcp->tcp_prot_mem[1] = sysctl_tcp_mem[1];
-       tcp->tcp_prot_mem[2] = sysctl_tcp_mem[2];
+       tcp->tcp_prot_mem[0] = net->ipv4.sysctl_tcp_mem[0];
+       tcp->tcp_prot_mem[1] = net->ipv4.sysctl_tcp_mem[1];
+       tcp->tcp_prot_mem[2] = net->ipv4.sysctl_tcp_mem[2];
        tcp->tcp_memory_pressure = 0;
 
        parent_cg = tcp_prot.proto_cgroup(parent);

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 7694c82..273f48d 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -1116,6 +1116,8 @@ static int __init inet6_init(void)
        if (err)
                goto static_sysctl_fail;
 #endif
+       tcpv6_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
+
        /*
         *      ipngwg API draft makes clear that the correct semantics
         *      for TCP and UDP is to consider one TCP and UDP instance

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 95d3cfb..906c7ca 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2215,7 +2215,6 @@ struct proto tcpv6_prot = {
        .memory_allocated       = &tcp_memory_allocated,
        .memory_pressure        = &tcp_memory_pressure,
        .orphan_count           = &tcp_orphan_count,
-       .sysctl_mem             = sysctl_tcp_mem,
        .sysctl_wmem            = sysctl_tcp_wmem,
        .sysctl_rmem            = sysctl_tcp_rmem,
        .max_header             = MAX_TCP_HEADER,