From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755375Ab2ALU2W (ORCPT ); Thu, 12 Jan 2012 15:28:22 -0500 Received: from shards.monkeyblade.net ([198.137.202.13]:40740 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755215Ab2ALU2T (ORCPT ); Thu, 12 Jan 2012 15:28:19 -0500 Date: Thu, 12 Jan 2012 12:28:16 -0800 (PST) Message-Id: <20120112.122816.1727420253535508242.davem@davemloft.net> To: glommer@parallels.com Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH] net: decrement memcg jump label when limit, not usage, is changed From: David Miller In-Reply-To: <1326370566-4286-1-git-send-email-glommer@parallels.com> References: <1326370566-4286-1-git-send-email-glommer@parallels.com> X-Mailer: Mew version 6.4 on Emacs 23.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Thu, 12 Jan 2012 12:28:17 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Glauber Costa Date: Thu, 12 Jan 2012 16:16:06 +0400 > The logic of the current code is that whenever we destroy > a cgroup that had its limit set (set meaning different than > maximum), we should decrement the jump_label counter. > Otherwise we assume it was never incremented. > > But what the code actually does is test for RES_USAGE > instead of RES_LIMIT. Usage being different than maximum > is likely to be true most of the time. > > The effect of this is that the key must become negative, > and since the jump_label test says: > > !!atomic_read(&key->enabled); > > we'll have jump_labels still on when no one else is > using this functionality. > > Signed-off-by: Glauber Costa > CC: David S. Miller Applied, thanks.