[Devel] [PATCH v6 4/8] per-cgroup tcp buffers control

Glauber Costa glommer at parallels.com
Mon Oct 10 03:24:24 PDT 2011


With all the infrastructure in place, this patch implements
per-cgroup control for tcp memory pressure handling.

Signed-off-by: Glauber Costa <glommer at parallels.com>
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujtisu.com>
CC: David S. Miller <davem at davemloft.net>
CC: Eric W. Biederman <ebiederm at xmission.com>
---
 include/linux/memcontrol.h |    4 +
 include/net/sock.h         |   14 ++++
 include/net/tcp.h          |   17 +++++
 mm/memcontrol.c            |  141 ++++++++++++++++++++++++++++++++++++++++++++
 net/core/sock.c            |   39 +++++++++++-
 net/ipv4/tcp.c             |   47 +++++++--------
 net/ipv4/tcp_ipv4.c        |   11 ++++
 net/ipv6/tcp_ipv6.c        |   10 +++-
 8 files changed, 255 insertions(+), 28 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 99a8ba2..a27dad9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -393,6 +393,10 @@ void sock_update_memcg(struct sock *sk);
 void sock_release_memcg(struct sock *sk);
 void memcg_sockets_allocated_dec(struct mem_cgroup *memcg, struct proto *prot);
 void memcg_sockets_allocated_inc(struct mem_cgroup *memcg, struct proto *prot);
+int tcp_init_cgroup(const struct proto *prot, struct cgroup *cgrp,
+		    struct cgroup_subsys *ss);
+void tcp_destroy_cgroup(const struct proto *prot, struct cgroup *cgrp,
+			struct cgroup_subsys *ss);
 #else
 /* memcontrol includes sockets.h, that includes memcontrol.h ... */
 static inline void memcg_sockets_allocated_dec(struct mem_cgroup *memcg,
diff --git a/include/net/sock.h b/include/net/sock.h
index 163f87b..efd7664 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -64,6 +64,8 @@
 #include <net/dst.h>
 #include <net/checksum.h>
 
+int sockets_populate(struct cgroup *cgrp, struct cgroup_subsys *ss);
+void sockets_destroy(struct cgroup *cgrp, struct cgroup_subsys *ss);
 /*
  * This structure really needs to be cleaned up.
  * Most of it is for TCP, and not used by any of
@@ -819,6 +821,18 @@ struct proto {
 	/* Pointer to the per-cgroup version of the the sysctl_mem field */
 	long			*(*prot_mem)(const struct mem_cgroup *memcg);
 
+	/*
+	 * cgroup specific init/deinit functions. 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)(const struct proto *prot,
+					       struct cgroup *cgrp,
+					       struct cgroup_subsys *ss);
+	void			(*destroy_cgroup)(const struct proto *prot,
+						  struct cgroup *cgrp,
+						  struct cgroup_subsys *ss);
 	int			*sysctl_wmem;
 	int			*sysctl_rmem;
 	int			max_header;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index eac7bf6..ec57cf2 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -31,6 +31,7 @@
 #include <linux/crypto.h>
 #include <linux/cryptohash.h>
 #include <linux/kref.h>
+#include <linux/res_counter.h>
 
 #include <net/inet_connection_sock.h>
 #include <net/inet_timewait_sock.h>
@@ -255,6 +256,21 @@ extern int sysctl_tcp_thin_linear_timeouts;
 extern int sysctl_tcp_thin_dupack;
 
 struct mem_cgroup;
+struct tcp_memcontrol {
+	/* per-cgroup tcp memory pressure knobs */
+	struct res_counter tcp_memory_allocated;
+	struct percpu_counter tcp_sockets_allocated;
+	/* those two are read-mostly, leave them at the end */
+	long tcp_prot_mem[3];
+	int tcp_memory_pressure;
+};
+
+extern long *tcp_sysctl_mem_nocg(const struct mem_cgroup *memcg);
+struct percpu_counter *sockets_allocated_tcp_nocg(const struct mem_cgroup *memcg);
+int *memory_pressure_tcp_nocg(const struct mem_cgroup *memcg);
+long memory_allocated_tcp_add_nocg(struct mem_cgroup *memcg, long val,
+				   int *parent_status);
+
 extern long *tcp_sysctl_mem(const struct mem_cgroup *memcg);
 struct percpu_counter *sockets_allocated_tcp(const struct mem_cgroup *memcg);
 int *memory_pressure_tcp(const struct mem_cgroup *memcg);
@@ -1023,6 +1039,7 @@ static inline void tcp_openreq_init(struct request_sock *req,
 	ireq->loc_port = tcp_hdr(skb)->dest;
 }
 
+extern void tcp_enter_memory_pressure_nocg(struct sock *sk);
 extern void tcp_enter_memory_pressure(struct sock *sk);
 
 static inline int keepalive_intvl_when(const struct tcp_sock *tp)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ad55b28..efff83b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -49,6 +49,9 @@
 #include <linux/cpu.h>
 #include <linux/oom.h>
 #include "internal.h"
+#ifdef CONFIG_INET
+#include <net/tcp.h>
+#endif
 
 #include <asm/uaccess.h>
 
@@ -294,6 +297,10 @@ struct mem_cgroup {
 	 */
 	struct mem_cgroup_stat_cpu nocpu_base;
 	spinlock_t pcp_counter_lock;
+
+#ifdef CONFIG_INET
+	struct tcp_memcontrol tcp;
+#endif
 };
 
 /* Stuffs for move charges at task migration. */
@@ -377,10 +384,12 @@ enum mem_type {
 #define MEM_CGROUP_RECLAIM_SOFT		(1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
 
 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);
+static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont);
 /* Writing them here to avoid exposing memcg's inner layout */
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
 #ifdef CONFIG_INET
 #include <net/sock.h>
+#include <net/ip.h>
 
 void sock_update_memcg(struct sock *sk)
 {
@@ -426,6 +435,119 @@ void memcg_sockets_allocated_inc(struct mem_cgroup *memcg, struct proto *prot)
 		percpu_counter_inc(prot->sockets_allocated(memcg));
 }
 EXPORT_SYMBOL(memcg_sockets_allocated_inc);
+
+/*
+ * 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.
+ */
+void tcp_enter_memory_pressure(struct sock *sk)
+{
+	struct mem_cgroup *memcg = sk->sk_cgrp;
+	if (!memcg->tcp.tcp_memory_pressure) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
+		memcg->tcp.tcp_memory_pressure = 1;
+	}
+}
+EXPORT_SYMBOL(tcp_enter_memory_pressure);
+
+#define CONSTCG(m) ((struct mem_cgroup *)(m))
+long *tcp_sysctl_mem(const struct mem_cgroup *memcg)
+{
+	return CONSTCG(memcg)->tcp.tcp_prot_mem;
+}
+EXPORT_SYMBOL(tcp_sysctl_mem);
+
+/*
+ * We will be passed a value in pages. But our limits are internally
+ * all in bytes. We need to convert it before testing the allocation,
+ * and convert it back when returning data to the network layer
+ */
+long memory_allocated_tcp_add(struct mem_cgroup *memcg, long val,
+			      int *parent_status)
+{
+	int ret = 0;
+	struct res_counter *failed;
+
+	if (val > 0) {
+		val <<= PAGE_SHIFT;
+		ret = res_counter_charge(&memcg->tcp.tcp_memory_allocated,
+					 val, &failed);
+		if (!ret)
+			*parent_status = UNDER_LIMIT;
+		else
+			*parent_status = OVER_LIMIT;
+	} else if (val < 0) {
+		if (*parent_status == OVER_LIMIT)
+			/*
+			 * res_counter charge already surely uncharged the
+			 * parent if something went wrong.
+			 */
+			WARN_ON(1);
+		else {
+			val = (-val) << PAGE_SHIFT;
+			res_counter_uncharge(&memcg->tcp.tcp_memory_allocated,
+					     val);
+		}
+	}
+
+	return res_counter_read_u64(&memcg->tcp.tcp_memory_allocated,
+				    RES_USAGE) >> PAGE_SHIFT;
+}
+EXPORT_SYMBOL(memory_allocated_tcp_add);
+
+int *memory_pressure_tcp(const struct mem_cgroup *memcg)
+{
+	return &CONSTCG(memcg)->tcp.tcp_memory_pressure;
+}
+EXPORT_SYMBOL(memory_pressure_tcp);
+
+struct percpu_counter *sockets_allocated_tcp(const struct mem_cgroup *memcg)
+{
+	return &CONSTCG(memcg)->tcp.tcp_sockets_allocated;
+}
+EXPORT_SYMBOL(sockets_allocated_tcp);
+
+static void tcp_create_cgroup(struct mem_cgroup *cg, struct cgroup_subsys *ss)
+{
+	struct res_counter *parent_res_counter = NULL;
+	struct mem_cgroup *parent = parent_mem_cgroup(cg);
+
+	if (parent)
+		parent_res_counter = &parent->tcp.tcp_memory_allocated;
+
+	cg->tcp.tcp_memory_pressure = 0;
+	res_counter_init(&cg->tcp.tcp_memory_allocated, parent_res_counter);
+	percpu_counter_init(&cg->tcp.tcp_sockets_allocated, 0);
+}
+
+int tcp_init_cgroup(const struct proto *prot, struct cgroup *cgrp,
+		    struct cgroup_subsys *ss)
+{
+	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+	/*
+	 * We need to initialize it at populate, not create time.
+	 * This is because net sysctl tables are not up until much
+	 * later
+	 */
+	memcg->tcp.tcp_prot_mem[0] = sysctl_tcp_mem[0];
+	memcg->tcp.tcp_prot_mem[1] = sysctl_tcp_mem[1];
+	memcg->tcp.tcp_prot_mem[2] = sysctl_tcp_mem[2];
+
+	return 0;
+}
+EXPORT_SYMBOL(tcp_init_cgroup);
+
+void tcp_destroy_cgroup(const struct proto *prot, struct cgroup *cgrp,
+			struct cgroup_subsys *ss)
+{
+	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+
+	percpu_counter_destroy(&memcg->tcp.tcp_sockets_allocated);
+}
+EXPORT_SYMBOL(tcp_destroy_cgroup);
+#undef CONSTCG
 #endif /* CONFIG_INET */
 #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
 
@@ -4835,14 +4957,27 @@ static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
 
 	ret = cgroup_add_files(cont, ss, kmem_cgroup_files,
 			       ARRAY_SIZE(kmem_cgroup_files));
+
+	if (!ret)
+		ret = sockets_populate(cont, ss);
 	return ret;
 };
 
+static void kmem_cgroup_destroy(struct cgroup_subsys *ss,
+				struct cgroup *cont)
+{
+	sockets_destroy(cont, ss);
+}
 #else
 static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
 {
 	return 0;
 }
+
+static void kmem_cgroup_destroy(struct cgroup_subsys *ss,
+				struct cgroup *cont)
+{
+}
 #endif
 
 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
@@ -5060,6 +5195,10 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 	mem->last_scanned_node = MAX_NUMNODES;
 	INIT_LIST_HEAD(&mem->oom_notify);
 
+#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_INET)
+	tcp_create_cgroup(mem, ss);
+#endif
+
 	if (parent)
 		mem->swappiness = mem_cgroup_swappiness(parent);
 	atomic_set(&mem->refcnt, 1);
@@ -5085,6 +5224,8 @@ static void mem_cgroup_destroy(struct cgroup_subsys *ss,
 {
 	struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
 
+	kmem_cgroup_destroy(ss, cont);
+
 	mem_cgroup_put(mem);
 }
 
diff --git a/net/core/sock.c b/net/core/sock.c
index 22ef143..3fa3ccb 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -135,6 +135,42 @@
 #include <net/tcp.h>
 #endif
 
+static DEFINE_RWLOCK(proto_list_lock);
+static LIST_HEAD(proto_list);
+
+int sockets_populate(struct cgroup *cgrp, struct cgroup_subsys *ss)
+{
+	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(proto, cgrp, ss);
+			if (ret)
+				goto out;
+	}
+
+	read_unlock(&proto_list_lock);
+	return ret;
+out:
+	list_for_each_entry_continue_reverse(proto, &proto_list, node)
+		if (proto->destroy_cgroup)
+			proto->destroy_cgroup(proto, cgrp, ss);
+	read_unlock(&proto_list_lock);
+	return ret;
+}
+
+void sockets_destroy(struct cgroup *cgrp, struct cgroup_subsys *ss)
+{
+	struct proto *proto;
+	read_lock(&proto_list_lock);
+	list_for_each_entry_reverse(proto, &proto_list, node)
+		if (proto->destroy_cgroup)
+			proto->destroy_cgroup(proto, cgrp, ss);
+	read_unlock(&proto_list_lock);
+}
+
 /*
  * Each address family might have different locking rules, so we have
  * one slock key per address family:
@@ -2262,9 +2298,6 @@ void sk_common_release(struct sock *sk)
 }
 EXPORT_SYMBOL(sk_common_release);
 
-static DEFINE_RWLOCK(proto_list_lock);
-static LIST_HEAD(proto_list);
-
 #ifdef CONFIG_PROC_FS
 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
 struct prot_inuse {
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index dc8f01e..259f6d9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -290,13 +290,6 @@ EXPORT_SYMBOL(sysctl_tcp_mem);
 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
  */
@@ -306,47 +299,51 @@ struct tcp_splice_state {
 	unsigned int flags;
 };
 
-/*
- * 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.
- */
+/* Current number of TCP sockets. */
+struct percpu_counter tcp_sockets_allocated;
+atomic_long_t tcp_memory_allocated;	/* Current allocated memory. */
 int tcp_memory_pressure __read_mostly;
 
-int *memory_pressure_tcp(const struct mem_cgroup *memcg)
+int *memory_pressure_tcp_nocg(const struct mem_cgroup *memcg)
 {
 	return &tcp_memory_pressure;
 }
-EXPORT_SYMBOL(memory_pressure_tcp);
+EXPORT_SYMBOL(memory_pressure_tcp_nocg);
 
-struct percpu_counter *sockets_allocated_tcp(const struct mem_cgroup *memcg)
+struct percpu_counter
+*sockets_allocated_tcp_nocg(const struct mem_cgroup *memcg)
 {
 	return &tcp_sockets_allocated;
 }
-EXPORT_SYMBOL(sockets_allocated_tcp);
+EXPORT_SYMBOL(sockets_allocated_tcp_nocg);
 
-void tcp_enter_memory_pressure(struct sock *sk)
+/*
+ * 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.
+ */
+void tcp_enter_memory_pressure_nocg(struct sock *sk)
 {
 	if (!tcp_memory_pressure) {
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
 		tcp_memory_pressure = 1;
 	}
 }
-EXPORT_SYMBOL(tcp_enter_memory_pressure);
+EXPORT_SYMBOL(tcp_enter_memory_pressure_nocg);
 
-long *tcp_sysctl_mem(const struct mem_cgroup *memcg)
+long *tcp_sysctl_mem_nocg(const struct mem_cgroup *memcg)
 {
 	return sysctl_tcp_mem;
 }
-EXPORT_SYMBOL(tcp_sysctl_mem);
+EXPORT_SYMBOL(tcp_sysctl_mem_nocg);
 
-long memory_allocated_tcp_add(struct mem_cgroup *memcg, long val,
-			      int *parent_status)
+long memory_allocated_tcp_add_nocg(struct mem_cgroup *memcg, long val,
+				   int *parent_status)
 {
 	return atomic_long_add_return(val, &tcp_memory_allocated);
 }
-EXPORT_SYMBOL(memory_allocated_tcp_add);
+EXPORT_SYMBOL(memory_allocated_tcp_add_nocg);
 
 /* Convert seconds to retransmits based on initial and max timeout */
 static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
@@ -3248,7 +3245,9 @@ void __init tcp_init(void)
 
 	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
 
+#ifndef CONFIG_CGROUP_MEM_RES_CTLR_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",
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7072060..aac71e9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2607,12 +2607,23 @@ struct proto tcp_prot = {
 	.hash			= inet_hash,
 	.unhash			= inet_unhash,
 	.get_port		= inet_csk_get_port,
+	.orphan_count		= &tcp_orphan_count,
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+	.init_cgroup		= tcp_init_cgroup,
+	.destroy_cgroup		= tcp_destroy_cgroup,
 	.enter_memory_pressure	= tcp_enter_memory_pressure,
 	.memory_pressure	= memory_pressure_tcp,
 	.sockets_allocated	= sockets_allocated_tcp,
 	.orphan_count		= &tcp_orphan_count,
 	.mem_allocated_add	= memory_allocated_tcp_add,
 	.prot_mem		= tcp_sysctl_mem,
+#else
+	.enter_memory_pressure	= tcp_enter_memory_pressure_nocg,
+	.memory_pressure	= memory_pressure_tcp_nocg,
+	.sockets_allocated	= sockets_allocated_tcp_nocg,
+	.mem_allocated_add	= memory_allocated_tcp_add_nocg,
+	.prot_mem		= tcp_sysctl_mem_nocg,
+#endif
 	.sysctl_wmem		= sysctl_tcp_wmem,
 	.sysctl_rmem		= sysctl_tcp_rmem,
 	.max_header		= MAX_TCP_HEADER,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index bdc0003..0a52587 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2200,12 +2200,20 @@ struct proto tcpv6_prot = {
 	.hash			= tcp_v6_hash,
 	.unhash			= inet_unhash,
 	.get_port		= inet_csk_get_port,
+	.orphan_count		= &tcp_orphan_count,
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
 	.enter_memory_pressure	= tcp_enter_memory_pressure,
 	.sockets_allocated	= sockets_allocated_tcp,
 	.mem_allocated_add	= memory_allocated_tcp_add,
 	.memory_pressure	= memory_pressure_tcp,
-	.orphan_count		= &tcp_orphan_count,
 	.prot_mem		= tcp_sysctl_mem,
+#else
+	.enter_memory_pressure	= tcp_enter_memory_pressure_nocg,
+	.sockets_allocated	= sockets_allocated_tcp_nocg,
+	.mem_allocated_add	= memory_allocated_tcp_add_nocg,
+	.memory_pressure	= memory_pressure_tcp_nocg,
+	.prot_mem		= tcp_sysctl_mem_nocg,
+#endif
 	.sysctl_wmem		= sysctl_tcp_wmem,
 	.sysctl_rmem		= sysctl_tcp_rmem,
 	.max_header		= MAX_TCP_HEADER,
-- 
1.7.6.4




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