foundations of per-cgroup memory pressure controlling.

This patch replaces all uses of struct sock fields' memory_pressure,
memory_allocated, sockets_allocated, and sysctl_mem to acessor
macros. Those macros can either receive a socket argument, or a mem_cgroup
argument, depending on the context they live in.

Since we're only doing a macro wrapping here, no performance impact at all is
expected in the case where we don't have cgroups disabled.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
CC: David S. Miller <davem@davemloft.net>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 48 insertions, 37 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index 9777da86aeac..a3d4205e7238 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1323,7 +1323,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
                 newsk->sk_wq = NULL;
 
                 if (newsk->sk_prot->sockets_allocated)
-                        percpu_counter_inc(newsk->sk_prot->sockets_allocated);
+                        sk_sockets_allocated_inc(newsk);
 
                 if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
                         net_enable_timestamp();
@@ -1713,28 +1713,28 @@ int __sk_mem_schedule(struct sock *sk, int size, int kind)
         long allocated;
 
         sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
-        allocated = atomic_long_add_return(amt, prot->memory_allocated);
+
+        allocated = sk_memory_allocated_add(sk, amt);
 
         /* Under limit. */
-        if (allocated <= prot->sysctl_mem[0]) {
-                if (prot->memory_pressure && *prot->memory_pressure)
-                        *prot->memory_pressure = 0;
+        if (allocated <= sk_prot_mem_limits(sk, 0)) {
+                sk_leave_memory_pressure(sk);
                 return 1;
         }
 
         /* Under pressure. */
-        if (allocated > prot->sysctl_mem[1])
-                if (prot->enter_memory_pressure)
-                        prot->enter_memory_pressure(sk);
+        if (allocated > sk_prot_mem_limits(sk, 1))
+                sk_enter_memory_pressure(sk);
 
         /* Over hard limit. */
-        if (allocated > prot->sysctl_mem[2])
+        if (allocated > sk_prot_mem_limits(sk, 2))
                 goto suppress_allocation;
 
         /* guarantee minimum buffer size under pressure */
         if (kind == SK_MEM_RECV) {
                 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
                         return 1;
+
         } else { /* SK_MEM_SEND */
                 if (sk->sk_type == SOCK_STREAM) {
                         if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
@@ -1744,13 +1744,13 @@ int __sk_mem_schedule(struct sock *sk, int size, int kind)
                                 return 1;
         }
 
-        if (prot->memory_pressure) {
+        if (sk_has_memory_pressure(sk)) {
                 int alloc;
 
-                if (!*prot->memory_pressure)
+                if (!sk_under_memory_pressure(sk))
                         return 1;
-                alloc = percpu_counter_read_positive(prot->sockets_allocated);
-                if (prot->sysctl_mem[2] > alloc *
+                alloc = sk_sockets_allocated_read_positive(sk);
+                if (sk_prot_mem_limits(sk, 2) > alloc *
                     sk_mem_pages(sk->sk_wmem_queued +
                                  atomic_read(&sk->sk_rmem_alloc) +
                                  sk->sk_forward_alloc))
@@ -1773,7 +1773,9 @@ suppress_allocation:
 
         /* Alas. Undo changes. */
         sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
-        atomic_long_sub(amt, prot->memory_allocated);
+
+        sk_memory_allocated_sub(sk, amt);
+
         return 0;
 }
 EXPORT_SYMBOL(__sk_mem_schedule);
@@ -1784,15 +1786,13 @@ EXPORT_SYMBOL(__sk_mem_schedule);
  */
 void __sk_mem_reclaim(struct sock *sk)
 {
-        struct proto *prot = sk->sk_prot;
-
-        atomic_long_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
-                   prot->memory_allocated);
+        sk_memory_allocated_sub(sk,
+                                sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
         sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
 
-        if (prot->memory_pressure && *prot->memory_pressure &&
-            (atomic_long_read(prot->memory_allocated) < prot->sysctl_mem[0]))
-                *prot->memory_pressure = 0;
+        if (sk_under_memory_pressure(sk) &&
+            (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
+                sk_leave_memory_pressure(sk);
 }
 EXPORT_SYMBOL(__sk_mem_reclaim);
 
@@ -2507,16 +2507,27 @@ static char proto_method_implemented(const void *method)
 {
         return method == NULL ? 'n' : 'y';
 }
+static long sock_prot_memory_allocated(struct proto *proto)
+{
+        return proto->memory_allocated != NULL ? proto_memory_allocated(proto): -1L;
+}
+
+static char *sock_prot_memory_pressure(struct proto *proto)
+{
+        return proto->memory_pressure != NULL ?
+        proto_memory_pressure(proto) ? "yes" : "no" : "NI";
+}
 
 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
 {
+
         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
                    proto->name,
                    proto->obj_size,
                    sock_prot_inuse_get(seq_file_net(seq), proto),
-                   proto->memory_allocated != NULL ? atomic_long_read(proto->memory_allocated) : -1L,
-                   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
+                   sock_prot_memory_allocated(proto),
+                   sock_prot_memory_pressure(proto),
                    proto->max_header,
                    proto->slab == NULL ? "no" : "yes",
                    module_name(proto->owner),
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 961eed4f510a..3569d8ecaeac 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -56,17 +56,17 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
 
         local_bh_disable();
         orphans = percpu_counter_sum_positive(&tcp_orphan_count);
-        sockets = percpu_counter_sum_positive(&tcp_sockets_allocated);
+        sockets = proto_sockets_allocated_sum_positive(&tcp_prot);
         local_bh_enable();
 
         socket_seq_show(seq);
         seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %ld\n",
                    sock_prot_inuse_get(net, &tcp_prot), orphans,
                    tcp_death_row.tw_count, sockets,
-                   atomic_long_read(&tcp_memory_allocated));
+                   proto_memory_allocated(&tcp_prot));
         seq_printf(seq, "UDP: inuse %d mem %ld\n",
                    sock_prot_inuse_get(net, &udp_prot),
-                   atomic_long_read(&udp_memory_allocated));
+                   proto_memory_allocated(&udp_prot));
         seq_printf(seq, "UDPLITE: inuse %d\n",
                    sock_prot_inuse_get(net, &udplite_prot));
         seq_printf(seq, "RAW: inuse %d\n",
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b9cbc351c511..f131d92d25ee 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -322,7 +322,7 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
         /* Check #1 */
         if (tp->rcv_ssthresh < tp->window_clamp &&
             (int)tp->rcv_ssthresh < tcp_space(sk) &&
-            !tcp_memory_pressure) {
+            !sk_under_memory_pressure(sk)) {
                 int incr;
 
                 /* Check #2. Increase window, if skb with such overhead
@@ -411,8 +411,8 @@ static void tcp_clamp_window(struct sock *sk)
 
         if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
             !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
-            !tcp_memory_pressure &&
-            atomic_long_read(&tcp_memory_allocated) < sysctl_tcp_mem[0]) {
+            !sk_under_memory_pressure(sk) &&
+            sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) {
                 sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
                                     sysctl_tcp_rmem[2]);
         }
@@ -4866,7 +4866,7 @@ static int tcp_prune_queue(struct sock *sk)
 
         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
                 tcp_clamp_window(sk);
-        else if (tcp_memory_pressure)
+        else if (sk_under_memory_pressure(sk))
                 tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
 
         tcp_collapse_ofo_queue(sk);
@@ -4932,11 +4932,11 @@ static int tcp_should_expand_sndbuf(const struct sock *sk)
                 return 0;
 
         /* If we are under global TCP memory pressure, do not expand.  */
-        if (tcp_memory_pressure)
+        if (sk_under_memory_pressure(sk))
                 return 0;
 
         /* If we are under soft global TCP memory pressure, do not expand.  */
-        if (atomic_long_read(&tcp_memory_allocated) >= sysctl_tcp_mem[0])
+        if (sk_memory_allocated(sk) >= sk_prot_mem_limits(sk, 0))
                 return 0;
 
         /* If we filled the congestion window, do not expand.  */
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c4b8b09db9f5..f48bf312cfe8 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1917,7 +1917,7 @@ static int tcp_v4_init_sock(struct sock *sk)
         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
 
         local_bh_disable();
-        percpu_counter_inc(&tcp_sockets_allocated);
+        sk_sockets_allocated_inc(sk);
         local_bh_enable();
 
         return 0;
@@ -1973,7 +1973,7 @@ void tcp_v4_destroy_sock(struct sock *sk)
                 tp->cookie_values = NULL;
         }
 
-        percpu_counter_dec(&tcp_sockets_allocated);
+        sk_sockets_allocated_dec(sk);
 }
 EXPORT_SYMBOL(tcp_v4_destroy_sock);
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index cf3068038942..8c8de2780c7a 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1922,7 +1922,7 @@ u32 __tcp_select_window(struct sock *sk)
         if (free_space < (full_space >> 1)) {
                 icsk->icsk_ack.quick = 0;
 
-                if (tcp_memory_pressure)
+                if (sk_under_memory_pressure(sk))
                         tp->rcv_ssthresh = min(tp->rcv_ssthresh,
                                                4U * tp->advmss);
 
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index aa39a692f4c8..40a41f077981 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -261,7 +261,7 @@ static void tcp_delack_timer(unsigned long data)
         }
 
 out:
-        if (tcp_memory_pressure)
+        if (sk_under_memory_pressure(sk))
                 sk_mem_reclaim(sk);
 out_unlock:
         bh_unlock_sock(sk);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 9d74eee334d6..b69c7030aba9 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1994,7 +1994,7 @@ static int tcp_v6_init_sock(struct sock *sk)
         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
 
         local_bh_disable();
-        percpu_counter_inc(&tcp_sockets_allocated);
+        sk_sockets_allocated_inc(sk);
         local_bh_enable();
 
         return 0;