From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759477AbXLAEbb (ORCPT ); Fri, 30 Nov 2007 23:31:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752972AbXLAEbQ (ORCPT ); Fri, 30 Nov 2007 23:31:16 -0500 Received: from rtr.ca ([76.10.145.34]:1523 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752829AbXLAEbP (ORCPT ); Fri, 30 Nov 2007 23:31:15 -0500 Message-ID: <4750E391.4060309@rtr.ca> Date: Fri, 30 Nov 2007 23:31:13 -0500 From: Mark Lord User-Agent: Thunderbird 2.0.0.9 (X11/20071031) MIME-Version: 1.0 To: Arjan van de Ven Cc: "Pallipadi, Venkatesh" , Andrew Morton , abelay@novell.com, lenb@kernel.org, rjw@sisk.pl, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: + restore-missing-sysfs-max_cstate-attr.patch added to -mm tree References: <200711302153.lAULrZ7n026255@imap1.linux-foundation.org> <924EFEDD5F540B4284297C4DC59F3DEE2FAE6A@orsmsx423.amr.corp.intel.com> <20071130142058.816d1693.akpm@linux-foundation.org> <924EFEDD5F540B4284297C4DC59F3DEE2FAEAF@orsmsx423.amr.corp.intel.com> <4750CC78.9070105@rtr.ca> <20071130190227.1976e682@laptopd505.fenrus.org> <4750D180.6080001@rtr.ca> <20071130191816.3e744205@laptopd505.fenrus.org> <4750D585.1030200@rtr.ca> <4750D899.4020905@rtr.ca> <4750DCDC.8030306@rtr.ca> In-Reply-To: <4750DCDC.8030306@rtr.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mark Lord wrote: > Arjan van de Ven wrote: >> On Fri, 30 Nov 2007 22:44:25 -0500 >> Mark Lord wrote: >>>> all you need to do in your kernel module is call ... >> set_acceptable_latency("mark", 5); >> >> and to remove the constraint again you just do >> >> remove_acceptable_latency("mark"); .. >>> Then why not have a sysfs entry for scripts to write tsoro >>> to trigger the exact same end result? :) >> >> that's what is in current -mm pretty much >> well not sysfs, but it goes via a file descriptor >> (so that if the process that sets the contraint dies, the latency >> requirement can be given up automatically) > ... > > But doesn't that approach also make it nearly impossible to script ???? ... Okay, I have a working trivial kernel module that I can load/unload to tweak this. But a simple sysfs attribute would be *so much* better as a permanent kernel feature. Binary interfaces (fd) are fine for some uses, but not nice for scripts. Cheers