From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932902AbYETOpu (ORCPT ); Tue, 20 May 2008 10:45:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756666AbYETOpm (ORCPT ); Tue, 20 May 2008 10:45:42 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:39179 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755559AbYETOpl (ORCPT ); Tue, 20 May 2008 10:45:41 -0400 Message-ID: <4832E423.5040708@bull.net> Date: Tue, 20 May 2008 16:45:55 +0200 From: Nadia Derbey Organization: BULL/DT/OSwR&D/Linux User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040115 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Michael Kerrisk Cc: Linux Kernel Mailing List , linux-mm@vger.kernel.org Subject: Re: [PATCH 1/8] Scaling msgmni to the amount of lowmem References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michael Kerrisk wrote: > Hello Nadia, > > Regarding your: > > [PATCH 1/8] Scaling msgmni to the amount of lowmem > http://article.gmane.org/gmane.linux.kernel/637849/ > which I see has made its way in 2.6.26-rc > > Your patch has the following change: > > -#define MSGPOOL (MSGMNI*MSGMNB/1024) /* size in kilobytes of message pool */ > +#define MSGPOOL (MSGMNI * MSGMNB) /* size in bytes of message pool */ > > Since this constitutes a kernel-userland interface change, so please > do CC me, so that I can change the man pages if needed. Oops, sorry for not doing it: I misunderstood the "unused" > > The man page (http://www.kernel.org/doc/man-pages/online/pages/man2/msgctl.2.html) > does indeed say that msgpool is "unused". But that meant "unused by > the kernel" (sorry -- I probably should have worded that text better). > And, as you spotted, the page also wrongly said the value is in > bytes. > > However, making this change affects the ABI. A userspace application > that was previously using msgctl(IPC_INFO) to retrieve the msgpool > field will be affected by the factor-of-1024 change. I strongly > suspect that there no such applications, or certainly none that care > (since this value is unused by the kernel). But was there a reason > for making this change, aside from the fact that the code and the man > page didn't agree? > No, that was the only reason. Should I repost a patch to set it back as it used to be? Regards Nadia