net: tcp_memcontrol: remove dead per-memcg count of allocated sockets

The number of allocated sockets is used for calculations in the soft
limit phase, where packets are accepted but the socket is under memory
pressure.
 Since there is no soft limit phase in tcp_memcontrol, and memory
pressure is only entered when packets are already dropped, this is
actually dead code.  Remove it.

As this is the last user of parent_cg_proto(), remove that too.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 85c437b..15acc04 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -87,7 +87,6 @@ enum mem_cgroup_events_target {
 
 struct cg_proto {
        struct page_counter     memory_allocated;       /* Current allocated memory. */
-       struct percpu_counter   sockets_allocated;      /* Current number of sockets. */
        int                     memory_pressure;
        bool                    active;
        long                    sysctl_mem[3];

diff --git a/include/net/sock.h b/include/net/sock.h
index d3b035c..1f15937 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1098,19 +1098,9 @@ static inline void sk_refcnt_debug_release(const struct sock *sk)
 
 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_NET)
 extern struct static_key memcg_socket_limit_enabled;
-static inline struct cg_proto *parent_cg_proto(struct proto *proto,
-                                              struct cg_proto *cg_proto)
-{
-       return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
-}
 #define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
 #else
 #define mem_cgroup_sockets_enabled 0
-static inline struct cg_proto *parent_cg_proto(struct proto *proto,
-                                              struct cg_proto *cg_proto)
-{
-       return NULL;
-}
 #endif
 
 static inline bool sk_stream_memory_free(const struct sock *sk)
@@ -1236,41 +1226,18 @@ sk_memory_allocated_sub(struct sock *sk, int amt)
 
 static inline void sk_sockets_allocated_dec(struct sock *sk)
 {
-       struct proto *prot = sk->sk_prot;
-
-       if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
-               struct cg_proto *cg_proto = sk->sk_cgrp;
-
-               for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
-                       percpu_counter_dec(&cg_proto->sockets_allocated);
-       }
-
-       percpu_counter_dec(prot->sockets_allocated);
+       percpu_counter_dec(sk->sk_prot->sockets_allocated);
 }
 
 static inline void sk_sockets_allocated_inc(struct sock *sk)
 {
-       struct proto *prot = sk->sk_prot;
-
-       if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
-               struct cg_proto *cg_proto = sk->sk_cgrp;
-
-               for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
-                       percpu_counter_inc(&cg_proto->sockets_allocated);
-       }
-
-       percpu_counter_inc(prot->sockets_allocated);
+       percpu_counter_inc(sk->sk_prot->sockets_allocated);
 }
 
 static inline int
 sk_sockets_allocated_read_positive(struct sock *sk)
 {
-       struct proto *prot = sk->sk_prot;
-
-       if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
-               return percpu_counter_read_positive(&sk->sk_cgrp->sockets_allocated);
-
-       return percpu_counter_read_positive(prot->sockets_allocated);
+       return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
 }
 
 static inline int

diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
index d07579a..6759e0d 100644 (file)
--- a/net/ipv4/tcp_memcontrol.c
+++ b/net/ipv4/tcp_memcontrol.c
@@ -32,7 +32,6 @@ int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
                counter_parent = &parent_cg->memory_allocated;
 
        page_counter_init(&cg_proto->memory_allocated, counter_parent);
-       percpu_counter_init(&cg_proto->sockets_allocated, 0, GFP_KERNEL);
 
        return 0;
 }
@@ -46,8 +45,6 @@ void tcp_destroy_cgroup(struct mem_cgroup *memcg)
        if (!cg_proto)
                return;
 
-       percpu_counter_destroy(&cg_proto->sockets_allocated);
-
        if (cg_proto->active)
                static_key_slow_dec(&memcg_socket_limit_enabled);