[PATCH v2 5/7] per-netns ipv4 sysctl_tcp_mem

Glauber Costa
2011-09-15T01:48:23Z

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>
CC: David S. Miller <davem@davemloft.net>
CC: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
CC: Eric W. Biederman <ebiederm@xmission.com>
---
include/net/netns/ipv4.h | 1 +
include/net/tcp.h | 1 -
mm/memcontrol.c | 9 +++++--
net/ipv4/sysctl_net_ipv4.c | 51 +++++++++++++++++++++++++++++++++++++------
net/ipv4/tcp.c | 13 ++--------
5 files changed, 54 insertions(+), 21 deletions(-)

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index d786b4f..bbd023a 100644
--- 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 ce3c211..257e1f9 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -231,7 +231,6 @@ 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/mm/memcontrol.c b/mm/memcontrol.c
index 7db430c..039cb79 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -358,6 +358,8 @@ static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
#ifdef CONFIG_INET
#include <net/tcp.h>
#include <net/ip.h>
+#include <linux/nsproxy.h>
+
void memcg_sock_mem_alloc(struct mem_cgroup *mem, struct proto *prot,
int amt, int *parent_failure)
{
@@ -470,6 +472,7 @@ int tcp_init_cgroup(struct proto *prot, struct cgroup *cgrp,
{
struct mem_cgroup *cg = mem_cgroup_from_cont(cgrp);
unsigned long limit;
+ struct net *net = current->nsproxy->net_ns;

cg->tcp_memory_pressure = 0;
atomic_long_set(&cg->tcp_memory_allocated, 0);
@@ -478,9 +481,9 @@ int tcp_init_cgroup(struct proto *prot, struct cgroup *cgrp,
limit = nr_free_buffer_pages() / 8;
limit = max(limit, 128UL);

- cg->tcp_prot_mem[0] = sysctl_tcp_mem[0];
- cg->tcp_prot_mem[1] = sysctl_tcp_mem[1];
- cg->tcp_prot_mem[2] = sysctl_tcp_mem[2];
+ cg->tcp_prot_mem[0] = net->ipv4.sysctl_tcp_mem[0];
+ cg->tcp_prot_mem[1] = net->ipv4.sysctl_tcp_mem[1];
+ cg->tcp_prot_mem[2] = net->ipv4.sysctl_tcp_mem[2];

tcp_init_cgroup_fill(prot, cgrp, ss);
return 0;
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 69fd720..bbd67ab 100644
--- 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 156b836..a94a0f1 100644
--- 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);

@@ -333,7 +331,7 @@ EXPORT_SYMBOL(tcp_enter_memory_pressure_nocg);

long *tcp_sysctl_mem_nocg(struct mem_cgroup *sg)
{
- return sysctl_tcp_mem;
+ return init_net.ipv4.sysctl_tcp_mem;
}
EXPORT_SYMBOL(tcp_sysctl_mem_nocg);

@@ -3296,14 +3294,9 @@ 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;
--
1.7.6