From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 3 Oct 2002 12:33:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 3 Oct 2002 12:33:33 -0400 Received: from dbl.q-ag.de ([80.146.160.66]:30641 "EHLO dbl.q-ag.de") by vger.kernel.org with ESMTP id ; Thu, 3 Oct 2002 12:33:31 -0400 Message-ID: <3D9C72A4.1090504@colorfullife.com> Date: Thu, 03 Oct 2002 18:39:00 +0200 From: Manfred Spraul User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 4.0) X-Accept-Language: en, de MIME-Version: 1.0 To: Cedric Roux , linux-kernel@vger.kernel.org Subject: Re: ipc - msg : memory usage too big ? Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > If it is seen as a problem, a solution might be to add > the memory overhead usage into the queue size, or add a > variable that counts the real memory used, and limits it > to a reasonable amount. > The limit in the number of messages was added a few years ago, older linux kernels [2.0, early 2.2] contain no limit at all :-( The implementation was choosen to avoid breaking apps that relied on the old behaviour: by default send x-byte messages, but if the queue is full, send a 0-byte, msgtype > 0 message that notifies a supervisor process that the queue is full. SUS permits a global system imposed limit on the number of messages, but IMHO 9 MB is not excessive [actually, 16*9MB, once for each queue] - root can reduce the limit further, if users abuse it. -- Manfred