From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760716AbXH2WS1 (ORCPT ); Wed, 29 Aug 2007 18:18:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754866AbXH2WSS (ORCPT ); Wed, 29 Aug 2007 18:18:18 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:40704 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751900AbXH2WSR (ORCPT ); Wed, 29 Aug 2007 18:18:17 -0400 Subject: Re: [-mm PATCH] Memory controller improve user interface From: Dave Hansen To: balbir@linux.vnet.ibm.com Cc: Andrew Morton , Linux Kernel Mailing List , Linux MM Mailing List , David Rientjes , Linux Containers , Paul Menage In-Reply-To: <46D5ED5C.9030405@linux.vnet.ibm.com> References: <20070829111030.9987.8104.sendpatchset@balbir-laptop> <1188413148.28903.113.camel@localhost> <46D5ED5C.9030405@linux.vnet.ibm.com> Content-Type: text/plain Date: Wed, 29 Aug 2007 15:18:14 -0700 Message-Id: <1188425894.28903.140.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2007-08-30 at 03:34 +0530, Balbir Singh wrote: > I've thought about this before. The problem is that a user could > set his limit to 10000 bytes, but would then see the usage and > limit round to the closest page boundary. This can be confusing > to a user. True, but we're lying if we allow a user to set their limit there, because we can't actually enforce a limit at 8,192 bytes vs 10,000. They're the same limit as far as the kernel is concerned. Why not just -EINVAL if the value isn't page-aligned? There are plenty of interfaces in the kernel that require userspace to know the page size, so this shouldn't be too difficult. -- Dave