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>

1 files changed, 6 insertions, 6 deletions

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.  */