| Re: [PATCH v9 3/9] socket: initial cgroup code. [message #44702 is a reply to message #44501] |
Fri, 23 December 2011 08:57   |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
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?
|
|
|
|
OpenVZ Forum
Members
Search
Help
Register
Login
Home
