From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id EFDED900117 for ; Mon, 3 Oct 2011 21:17:27 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 467423EE0C1 for ; Tue, 4 Oct 2011 10:17:25 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 2D16C45DE54 for ; Tue, 4 Oct 2011 10:17:25 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 134B245DE51 for ; Tue, 4 Oct 2011 10:17:25 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id F34671DB803E for ; Tue, 4 Oct 2011 10:17:24 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.240.81.146]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id BCCFF1DB803F for ; Tue, 4 Oct 2011 10:17:24 +0900 (JST) Date: Tue, 4 Oct 2011 10:16:33 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH v4 4/8] per-cgroup tcp buffers control Message-Id: <20111004101633.6b44201d.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1317637123-18306-5-git-send-email-glommer@parallels.com> References: <1317637123-18306-1-git-send-email-glommer@parallels.com> <1317637123-18306-5-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, paul@paulmenage.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 On Mon, 3 Oct 2011 14:18:39 +0400 Glauber Costa wrote: > With all the infrastructure in place, this patch implements > per-cgroup control for tcp memory pressure handling. > > Signed-off-by: Glauber Costa > CC: David S. Miller > CC: Hiroyouki Kamezawa > CC: Eric W. Biederman Reviewed-by: KAMEZAWA Hiroyuki One question. > +void tcp_enter_memory_pressure(struct sock *sk) > +{ > + struct mem_cgroup *memcg = sk->sk_cgrp; > + if (!memcg->tcp.tcp_memory_pressure) { > + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); > + memcg->tcp.tcp_memory_pressure = 1; > + } > +} It seems memcg->tcp.tcp_memory_pressure has no locks and not atomic. no problematic race ? 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