From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754159AbZBRAUT (ORCPT ); Tue, 17 Feb 2009 19:20:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751454AbZBRAUF (ORCPT ); Tue, 17 Feb 2009 19:20:05 -0500 Received: from bear.ext.ti.com ([192.94.94.41]:40897 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751396AbZBRAUD convert rfc822-to-8bit (ORCPT ); Tue, 17 Feb 2009 19:20:03 -0500 From: "Woodruff, Richard" To: Arjan van de Ven CC: Brian Swetland , "Rafael J. Wysocki" , Alan Stern , Kyle Moffett , Oliver Neukum , Benjamin Herrenschmidt , pm list , LKML , =?iso-8859-1?Q?Arve_Hj=F8nnev=E5g?= , Pavel Machek , Nigel Cunningham , mark gross , Uli Luckas , Igor Stoppa , Len Brown , Matthew Garrett Date: Tue, 17 Feb 2009 18:18:59 -0600 Subject: RE: [RFD] Automatic suspend Thread-Topic: [RFD] Automatic suspend Thread-Index: AcmRXHsHw28cf6E3RTKQDl9tHZd2UQAACbcg Message-ID: <13B9B4C6EF24D648824FF11BE896716203772614AD@dlee02.ent.ti.com> References: <13B9B4C6EF24D648824FF11BE896716203771DD01B@dlee02.ent.ti.com> <20090216145948.6fea81c3@infradead.org> <200902170019.40599.rjw@sisk.pl> <20090216232329.GA15678@srcf.ucam.org> <20090217142001.GB12378@bulgaria.corp.google.com> <20090217064630.688bf639@infradead.org> <20090217145141.GA26158@srcf.ucam.org> <20090217065622.3e0a9956@infradead.org> <13B9B4C6EF24D648824FF11BE896716203771DD342@dlee02.ent.ti.com> <20090217160421.12bc851f@infradead.org> In-Reply-To: <20090217160421.12bc851f@infradead.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Tue, 17 Feb 2009 09:32:46 -0600 > "Woodruff, Richard" wrote: > > > > so use range timers / timer slack for those apps that you do not > > > trust. That is not a big deal, and solves the issue of timer > > > wakeups... > > > > I not so sure it is that straight forward in practice. End systems > > integrate a lot of 3rd party software who view performance 1st and > > have no thought of power. > > you know that with the range timers/slack, you can control the > "rounding" of the timer of the application, right? I've not explored user space for this. Can on a per-application basis some controlling application cause timers of a target process to be rounded or is it global? Or do you need to link the new application to use special glib variants (as described in OLS papers a few years ago)? > You can *directly* throttle the number of wakeups an application causes > that way to a value you set. Are you talking about your work as seen in lwn.net summary? http://lwn.net/Articles/296578/ Your change here does look like something which could be used to control timers. Don't you still need some dynamic way to set the fuzz/slack if its globally applied? It seems like you might want some timers precise and others fuzzy. Would the holding of a wakelock or some activity counter be a good trigger for switching rounding time? If wakelocks held "minor adjustment" else "major adjustment" Thanks for the good pointer assuming I understood it in quick scan. Thanks, Richard W.