From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx123.postini.com [74.125.245.123]) by kanga.kvack.org (Postfix) with SMTP id ACC436B004D for ; Fri, 23 Dec 2011 03:58:31 -0500 (EST) Message-ID: <4EF4428D.6010103@parallels.com> Date: Fri, 23 Dec 2011 12:57:49 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v9 3/9] socket: initial cgroup code. References: <1323676029-5890-1-git-send-email-glommer@parallels.com> <1323676029-5890-4-git-send-email-glommer@parallels.com> <20111222211028.GB3916@redhat.com> In-Reply-To: <20111222211028.GB3916@redhat.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Jason Baron Cc: davem@davemloft.net, linux-kernel@vger.kernel.org, paul@paulmenage.org, lizf@cn.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, ebiederm@xmission.com, gthelen@google.com, netdev@vger.kernel.org, linux-mm@kvack.org, kirill@shutemov.name, avagin@parallels.com, devel@openvz.org, eric.dumazet@gmail.com, cgroups@vger.kernel.org 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? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org