From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Belay Subject: Re: [RFC][PATCH 2/2] ACPI: handle timer ticks proactively Date: Tue, 05 Sep 2006 11:16:00 -0400 Message-ID: <1157469360.3420.14.camel@localhost.localdomain> References: <20060904131027.GD6279@ucw.cz> <20060905082855.GC5082@elf.ucw.cz> <20060905085319.GA2237@elf.ucw.cz> <20060905090328.GA4888@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from peabody.ximian.com ([130.57.169.10]:31429 "EHLO peabody.ximian.com") by vger.kernel.org with ESMTP id S965101AbWIEPNX (ORCPT ); Tue, 5 Sep 2006 11:13:23 -0400 In-Reply-To: <20060905090328.GA4888@elf.ucw.cz> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Pavel Machek Cc: len.brown@intel.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux@dominikbrodowski.net, arjan@linux.intel.com On Tue, 2006-09-05 at 11:03 +0200, Pavel Machek wrote: > Hi! > > > > > This patch takes advantage of the infrastructure introduced in the last > > > > patch, and allows the processor idle algorithm to proactively choose a > > > > c-state based on the time the next timer interrupt is expected to occur. > > > > It preserves the residency metric, so the algorithm should, in theory, > > > > remain effective against bursts of activity from other interrupt > > > > sources. > > > > > > > > This patch is mostly intended to be illustrative. There may be some > > > > "#ifdef CONFIG_ACPI" issues, and I would appreciate any advice on > > > > implementing this more cleanly. > > > > Okay, just to get you some feedback: > > > > It seems to change things a _lot_. Power consumption with usb modules > > loaded went from 14315mW to 13800mW -- that is huge > > deal. Unfortunately something strange is going on: with stock kernel, > > power consumption is mostly constant. With your patch, it varies a > > lot, at 2 second timescale. > > > > Power consumption with usb unloaded (only way to get reasonable power > > on x60) went from stable 10450mW to something rapidly changing, and > > probably even worse than original: > > I also noticed that with your patch, bus master activity tends to be constant?! Is this the case even when userspace touches the disk? On my hardware I see a constant flow of short BM activity bursts. Thanks, Adam