With all the infrastructure in place, this patch implements
per-cgroup control for tcp memory pressure handling.
Signed-off-by: Glauber Costa <glommer@xxxxxxxxxxxxx>
CC: David S. Miller <davem@xxxxxxxxxxxxx>
CC: Hiroyouki Kamezawa <kamezawa.hiroyu@xxxxxxxxxxxxxx>
CC: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
include/linux/kmem_cgroup.h | 7 ++++
include/net/sock.h | 10 ++++++-
mm/kmem_cgroup.c | 10 ++++++-
net/core/sock.c | 18 +++++++++++
net/ipv4/tcp.c | 67 +++++++++++++++++++++++++++++++++++++-----
5 files changed, 102 insertions(+), 10 deletions(-)
diff --git a/include/linux/kmem_cgroup.h b/include/linux/kmem_cgroup.h
index d983ba8..89ad0a1 100644
--- a/include/linux/kmem_cgroup.h
+++ b/include/linux/kmem_cgroup.h
@@ -23,6 +23,13 @@
struct kmem_cgroup {
struct cgroup_subsys_state css;
struct kmem_cgroup *parent;
+
+#ifdef CONFIG_INET
+ int tcp_memory_pressure;
+ atomic_long_t tcp_memory_allocated;
+ struct percpu_counter tcp_sockets_allocated;
+ long tcp_prot_mem[3];
+#endif
};
diff --git a/include/net/sock.h b/include/net/sock.h
index ab65640..91424e3 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -64,6 +64,7 @@
#include <net/dst.h>
#include <net/checksum.h>
+int sockets_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
/*
* This structure really needs to be cleaned up.
* Most of it is for TCP, and not used by any of
@@ -814,7 +815,14 @@ struct proto {
int *(*memory_pressure)(struct kmem_cgroup *sg);
/* Pointer to the per-cgroup version of the the sysctl_mem field */
long *(*prot_mem)(struct kmem_cgroup *sg);
-
+ /*
+ * cgroup specific initialization function. Called once for all
+ * protocols that implement it, from cgroups populate function.
+ * This function has to setup any files the protocol want to
+ * appear in the kmem cgroup filesystem.
+ */
+ int (*init_cgroup)(struct cgroup *cgrp,
+ struct cgroup_subsys *ss);
int *sysctl_wmem;
int *sysctl_rmem;
int max_header;
diff --git a/mm/kmem_cgroup.c b/mm/kmem_cgroup.c
index 7950e69..5e53d66 100644
--- a/mm/kmem_cgroup.c
+++ b/mm/kmem_cgroup.c
@@ -17,16 +17,24 @@
#include <linux/cgroup.h>
#include <linux/slab.h>
#include <linux/kmem_cgroup.h>
+#include <net/sock.h>
static int kmem_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
{
- return 0;
+ int ret = 0;
+#ifdef CONFIG_NET
+ ret = sockets_populate(ss, cgrp);
+#endif
+ return ret;
}
static void
kmem_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
{
struct kmem_cgroup *cg = kcg_from_cgroup(cgrp);
+#ifdef CONFIG_INET
+ percpu_counter_destroy(&cg->tcp_sockets_allocated);
+#endif
kfree(cg);
}
diff --git a/net/core/sock.c b/net/core/sock.c
index ead9c02..9d833cf 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -134,6 +134,24 @@
#include <net/tcp.h>
#endif
+static DEFINE_RWLOCK(proto_list_lock);
+static LIST_HEAD(proto_list);
+
+int sockets_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ struct proto *proto;
+ int ret = 0;
+
+ read_lock(&proto_list_lock);
+ list_for_each_entry(proto, &proto_list, node) {
+ if (proto->init_cgroup)
+ ret |= proto->init_cgroup(cgrp, ss);
+ }
+ read_unlock(&proto_list_lock);
+
+ return ret;
+}
+
/*
* Each address family might have different locking rules, so we have
* one slock key per address family:
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 76f03ed..0725dc4 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -289,13 +289,6 @@ int sysctl_tcp_rmem[3] __read_mostly;
EXPORT_SYMBOL(sysctl_tcp_rmem);
EXPORT_SYMBOL(sysctl_tcp_wmem);
-atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
-
-/*
- * Current number of TCP sockets.
- */
-struct percpu_counter tcp_sockets_allocated;
-
/*
* TCP splice context
*/
@@ -305,13 +298,68 @@ struct tcp_splice_state {
unsigned int flags;
};
+#ifdef CONFIG_CGROUP_KMEM
/*
* Pressure flag: try to collapse.
* Technical note: it is used by multiple contexts non atomically.
* All the __sk_mem_schedule() is of this nature: accounting
* is strict, actions are advisory and have some latency.
*/
-int tcp_memory_pressure __read_mostly;
+void tcp_enter_memory_pressure(struct sock *sk)
+{
+ struct kmem_cgroup *sg = sk->sk_cgrp;
+ if (!sg->tcp_memory_pressure) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
+ sg->tcp_memory_pressure = 1;
+ }
+}
+
+long *tcp_sysctl_mem(struct kmem_cgroup *sg)
+{
+ return sg->tcp_prot_mem;
+}
+
+atomic_long_t *memory_allocated_tcp(struct kmem_cgroup *sg)
+{
+ return &(sg->tcp_memory_allocated);
+}
+
+int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
+{
+ struct kmem_cgroup *sg = kcg_from_cgroup(cgrp);
+ unsigned long limit;
+ struct net *net = current->nsproxy->net_ns;
+
+ sg->tcp_memory_pressure = 0;
+ atomic_long_set(&sg->tcp_memory_allocated, 0);
+ percpu_counter_init(&sg->tcp_sockets_allocated, 0);
+
+ limit = nr_free_buffer_pages() / 8;
+ limit = max(limit, 128UL);
+
+ sg->tcp_prot_mem[0] = net->ipv4.sysctl_tcp_mem[0];
+ sg->tcp_prot_mem[1] = net->ipv4.sysctl_tcp_mem[1];
+ sg->tcp_prot_mem[2] = net->ipv4.sysctl_tcp_mem[2];
+
+ return 0;
+}
+EXPORT_SYMBOL(tcp_init_cgroup);
+
+int *memory_pressure_tcp(struct kmem_cgroup *sg)
+{
+ return &sg->tcp_memory_pressure;
+}
+
+struct percpu_counter *sockets_allocated_tcp(struct kmem_cgroup *sg)
+{
+ return &sg->tcp_sockets_allocated;
+}
+#else
+
+/* Current number of TCP sockets. */
+struct percpu_counter tcp_sockets_allocated;
+atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
+int tcp_memory_pressure;
int *memory_pressure_tcp(struct kmem_cgroup *sg)
{
@@ -340,6 +388,7 @@ atomic_long_t *memory_allocated_tcp(struct kmem_cgroup *sg)
{
return &tcp_memory_allocated;
}
+#endif /* CONFIG_CGROUP_KMEM */
EXPORT_SYMBOL(memory_pressure_tcp);
EXPORT_SYMBOL(sockets_allocated_tcp);
@@ -3247,7 +3296,9 @@ void __init tcp_init(void)
BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
+#ifndef CONFIG_CGROUP_KMEM
percpu_counter_init(&tcp_sockets_allocated, 0);
+#endif
percpu_counter_init(&tcp_orphan_count, 0);
tcp_hashinfo.bind_bucket_cachep =
kmem_cache_create("tcp_bind_bucket",
--
1.7.6
--
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