Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262544AbUKWBpj (ORCPT ); Mon, 22 Nov 2004 20:45:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262488AbUKWBi3 (ORCPT ); Mon, 22 Nov 2004 20:38:29 -0500 Received: from emailhub.stusta.mhn.de ([141.84.69.5]:46095 "HELO mailout.stusta.mhn.de") by vger.kernel.org with SMTP id S261212AbUKWBhZ (ORCPT ); Mon, 22 Nov 2004 20:37:25 -0500 Date: Tue, 23 Nov 2004 02:37:20 +0100 From: Adrian Bunk To: Len Brown Cc: Chris Wright , Linus Torvalds , Bjorn Helgaas , Kernel Mailing List , Andrew Morton Subject: Re: why use ACPI (Re: 2.6.10-rc2 doesn't boot (if no floppy device)) Message-ID: <20041123013720.GA4371@stusta.de> References: <20041115152721.U14339@build.pdx.osdl.net> <1100819685.987.120.camel@d845pe> <20041118230948.W2357@build.pdx.osdl.net> <1100941324.987.238.camel@d845pe> <20041120124001.GA2829@stusta.de> <1101148138.20008.6.camel@d845pe> <20041123004619.GQ19419@stusta.de> <1101172056.20006.153.camel@d845pe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1101172056.20006.153.camel@d845pe> User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2495 Lines: 73 On Mon, Nov 22, 2004 at 08:07:36PM -0500, Len Brown wrote: > On Mon, 2004-11-22 at 19:46, Adrian Bunk wrote: > > > Not needed "pressing the power button when you halt the system" is the > > "killer application" for using ACPI for me... > > Yes, thats certainly one that people notice right away. Laptops have > had soft poweroff with APM for a while, but desktops and servers never > adopted APM, so soft-power-off is generally a new feature with ACPI for > them. That's wrong. My old desktop computer (with a VIA MVP3 chipset and an AMD K6 cpu) I bought in 1998 did power off fine under Linux using APM. > Enabling IOAPIC is one that a lot of people like, because it results in > less interrupt sharing and better performance than PIC mode. But if you > don't load your system much you may not notice any difference. I saw kernel: APIC error on CPU0: 00(02) ... kernel: APIC error on CPU0: 02(02) on my computer and decided disabling APIC was the easiest way to solve them... > Next people tend to notice fan speed, because they can hear it. > If you load processor and thermal, you'll probably see some > /proc/acpi/thermal/thermal_zone/*/temperature and you'll > probably find that it stays lower if you keep processor > loaded versus when you do not. /proc/acpi/thermal/thermal_zone is empty on my computer. > This is usually because of power-saving c-csates in idle, > which you can observe in /proc/acpi/processor/*/power > and the higher the C-state, the more power you save. active state: C1 default state: C1 bus master activity: 00000000 states: *C1: promotion[--] demotion[--] latency[000] usage[00000000] C2: C3: > Also, CPUFREQ usually often on ACPI, and that can save > power even when the system is not idle, and this results > in lower temperatures and hopefully slower fan speeds. My computer has a desktop Athlon... > cheers, > -Len cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/