From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx116.postini.com [74.125.245.116]) by kanga.kvack.org (Postfix) with SMTP id 9261E6B0068 for ; Thu, 8 Dec 2011 21:07:11 -0500 (EST) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id CF3523EE0C0 for ; Fri, 9 Dec 2011 11:07:09 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id B3B4945DF5A for ; Fri, 9 Dec 2011 11:07:09 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 91A9445DF56 for ; Fri, 9 Dec 2011 11:07:09 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 84E291DB8041 for ; Fri, 9 Dec 2011 11:07:09 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 2FE401DB803A for ; Fri, 9 Dec 2011 11:07:09 +0900 (JST) Date: Fri, 9 Dec 2011 11:05:50 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH v8 3/9] socket: initial cgroup code. Message-Id: <20111209110550.fc740b81.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1323120903-2831-4-git-send-email-glommer@parallels.com> References: <1323120903-2831-1-git-send-email-glommer@parallels.com> <1323120903-2831-4-git-send-email-glommer@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: linux-kernel@vger.kernel.org, lizf@cn.fujitsu.com, ebiederm@xmission.com, davem@davemloft.net, 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, hannes@cmpxchg.org, mhocko@suse.cz, KAMEZAWA Hiroyuki On Mon, 5 Dec 2011 19:34:57 -0200 Glauber Costa wrote: > The goal of this work is to move the memory pressure tcp > controls to a cgroup, instead of just relying on global > conditions. > > To avoid excessive overhead in the network fast paths, > the code that accounts allocated memory to a cgroup is > hidden inside a static_branch(). This branch is patched out > until the first non-root cgroup is created. So when nobody > is using cgroups, even if it is mounted, no significant performance > penalty should be seen. > > This patch handles the generic part of the code, and has nothing > tcp-specific. > > Signed-off-by: Glauber Costa > CC: Kirill A. Shutemov > CC: KAMEZAWA Hiroyuki > CC: David S. Miller > CC: Eric W. Biederman > CC: Eric Dumazet I already replied Reviewed-by: but... > +/* Writing them here to avoid exposing memcg's inner layout */ > +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM > +#ifdef CONFIG_INET > +#include > + > +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(); > + } > +} Here, you do mem_cgroup_get() if !mem_cgroup_is_root(). > +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); > + } > +} > You don't check !mem_cgroup_is_root(). Hm, root memcg will not be freed by this ? Thanks, -Kame -- 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