From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 356C49000F0 for ; Mon, 3 Oct 2011 06:48:56 -0400 (EDT) Message-ID: <4E8992EF.30001@parallels.com> Date: Mon, 3 Oct 2011 14:48:15 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v4 2/8] socket: initial cgroup code. References: <1317637123-18306-1-git-send-email-glommer@parallels.com> <1317637123-18306-3-git-send-email-glommer@parallels.com> <20111003104733.GB29312@shutemov.name> In-Reply-To: <20111003104733.GB29312@shutemov.name> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: linux-kernel@vger.kernel.org, paul@paulmenage.org, lizf@cn.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, ebiederm@xmission.com, davem@davemloft.net, gthelen@google.com, netdev@vger.kernel.org, linux-mm@kvack.org, avagin@parallels.com On 10/03/2011 02:47 PM, Kirill A. Shutemov wrote: > On Mon, Oct 03, 2011 at 02:18:37PM +0400, Glauber Costa wrote: >> We aim to control the amount of kernel memory pinned at any >> time by tcp sockets. To lay the foundations for this work, >> this patch adds a pointer to the kmem_cgroup to the socket >> structure. >> >> Signed-off-by: Glauber Costa >> CC: David S. Miller >> CC: Hiroyouki Kamezawa >> CC: Eric W. Biederman >> --- >> include/linux/memcontrol.h | 15 +++++++++++++++ >> include/net/sock.h | 2 ++ >> mm/memcontrol.c | 33 +++++++++++++++++++++++++++++++++ >> net/core/sock.c | 3 +++ >> 4 files changed, 53 insertions(+), 0 deletions(-) >> >> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h >> index 3b535db..2cb9226 100644 >> --- a/include/linux/memcontrol.h >> +++ b/include/linux/memcontrol.h >> @@ -395,5 +395,20 @@ mem_cgroup_print_bad_page(struct page *page) >> } >> #endif >> >> +#ifdef CONFIG_INET >> +struct sock; >> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM >> +void sock_update_memcg(struct sock *sk); >> +void sock_release_memcg(struct sock *sk); >> + >> +#else >> +static inline void sock_update_memcg(struct sock *sk) >> +{ >> +} >> +static inline void sock_release_memcg(struct sock *sk) >> +{ >> +} >> +#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */ >> +#endif /* CONFIG_INET */ >> #endif /* _LINUX_MEMCONTROL_H */ >> >> diff --git a/include/net/sock.h b/include/net/sock.h >> index 8e4062f..afe1467 100644 >> --- a/include/net/sock.h >> +++ b/include/net/sock.h >> @@ -228,6 +228,7 @@ struct sock_common { >> * @sk_security: used by security modules >> * @sk_mark: generic packet mark >> * @sk_classid: this socket's cgroup classid >> + * @sk_cgrp: this socket's kernel memory (kmem) cgroup >> * @sk_write_pending: a write to stream socket waits to start >> * @sk_state_change: callback to indicate change in the state of the sock >> * @sk_data_ready: callback to indicate there is data to be processed >> @@ -339,6 +340,7 @@ struct sock { >> #endif >> __u32 sk_mark; >> u32 sk_classid; >> + struct mem_cgroup *sk_cgrp; >> void (*sk_state_change)(struct sock *sk); >> void (*sk_data_ready)(struct sock *sk, int bytes); >> void (*sk_write_space)(struct sock *sk); >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 8aaf4ce..08a520e 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -339,6 +339,39 @@ struct mem_cgroup { >> spinlock_t pcp_counter_lock; >> }; >> >> +/* Writing them here to avoid exposing memcg's inner layout */ >> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM >> +#ifdef CONFIG_INET >> +#include >> + >> +void sock_update_memcg(struct sock *sk) >> +{ >> + /* right now a socket spends its whole life in the same cgroup */ >> + BUG_ON(sk->sk_cgrp); > > Do we really want to panic in this case? > > What about WARN() + return? Kirill, I am keeping this code just to have something workable in between. If you take a look at the last patch, this hunk is going away anyway. So if you don't oppose it, I'll just keep it to avoid rebasing it. > Otherwise: Acked-by: Kirill A. Shutemov > >> + >> + rcu_read_lock(); >> + sk->sk_cgrp = mem_cgroup_from_task(current); >> + >> + /* >> + * We don't need to protect against anything task-related, because >> + * we are basically stuck with the sock pointer that won't change, >> + * even if the task that originated the socket changes cgroups. >> + * >> + * What we do have to guarantee, is that the chain leading us to >> + * the top level won't change under our noses. Incrementing the >> + * reference count via cgroup_exclude_rmdir guarantees that. >> + */ >> + cgroup_exclude_rmdir(mem_cgroup_css(sk->sk_cgrp)); >> + rcu_read_unlock(); >> +} > -- 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