On 12/23/2011 01:10 AM, Jason Baron wrote:
On Mon, Dec 12, 2011 at 11:47:03AM +0400, Glauber Costa wrote:
+
+static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
+void sock_update_memcg(struct sock *sk)
+{
+ /* A socket spends its whole life in the same cgroup */
+ if (sk->sk_cgrp) {
+ WARN_ON(1);
+ return;
+ }
+ if (static_branch(&memcg_socket_limit_enabled)) {
+ struct mem_cgroup *memcg;
+
+ BUG_ON(!sk->sk_prot->proto_cgroup);
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_task(current);
+ if (!mem_cgroup_is_root(memcg)) {
+ mem_cgroup_get(memcg);
+ sk->sk_cgrp = sk->sk_prot->proto_cgroup(memcg);
+ }
+ rcu_read_unlock();
+ }
+}
+EXPORT_SYMBOL(sock_update_memcg);
+
+void sock_release_memcg(struct sock *sk)
+{
+ if (static_branch(&memcg_socket_limit_enabled)&& sk->sk_cgrp) {
+ struct mem_cgroup *memcg;
+ WARN_ON(!sk->sk_cgrp->memcg);
+ memcg = sk->sk_cgrp->memcg;
+ mem_cgroup_put(memcg);
+ }
+}
Hi Glauber,
I think for 'sock_release_memcg()', you want:
static inline sock_release_memcg(sk)
{
if (static_branch())
__sock_release_memcg();
}
And then re-define the current sock_release_memcg -> __sock_release_memcg().
In that way the straight line path is a single no-op. As currently
written, there is function call and then an immediate return.
Hello Jason,
Thanks for the tip. I may be wrong here, but I don't think that the
release performance matters to that level. But your suggestion seems
good nevertheless. Since this is already sitting on a tree, would you
like to send a patch for that?
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