From owner-freebsd-stable@FreeBSD.ORG Sat Dec 17 23:58:29 2005 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4084316A41F for ; Sat, 17 Dec 2005 23:58:29 +0000 (GMT) (envelope-from oberman@es.net) Received: from postal1.es.net (postal1.es.net [198.128.3.205]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0537A43D5A for ; Sat, 17 Dec 2005 23:58:27 +0000 (GMT) (envelope-from oberman@es.net) Received: from ptavv.es.net ([198.128.4.29]) by postal1.es.net (Postal Node 1) with ESMTP (SSL) id IBA74465; Sat, 17 Dec 2005 15:58:24 -0800 Received: from ptavv (localhost [127.0.0.1]) by ptavv.es.net (Tachyon Server) with ESMTP id BADD15D07; Sat, 17 Dec 2005 15:58:23 -0800 (PST) To: hartzell@alerce.com In-reply-to: Your message of "Fri, 16 Dec 2005 16:05:51 PST." <17315.22111.426723.110802@satchel.alerce.com> Date: Sat, 17 Dec 2005 15:58:23 -0800 From: "Kevin Oberman" Message-Id: <20051217235823.BADD15D07@ptavv.es.net> Cc: freebsd-stable@freebsd.org Subject: Re: HEADS UP: Release schedule for 2006 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Dec 2005 23:58:29 -0000 > From: George Hartzell > Date: Fri, 16 Dec 2005 16:05:51 -0800 > > Kevin Oberman writes: > > [...] > > No. There is no conflict between Cx states and EST. Cx states specifies > > how deeply the CPU will sleep when idle. EST controls processor speed > > and voltage. In most cases, your REALLY want to use both of these. They > > are very significant in saving power. (Of course, USB tends to limit the > > effectiveness of Cx states. I need to run without USB to get really good > > battery life and to make suspend (S3) really ut power drain. > > Can you expand a bit on that "Of course USB...". What's the problem > with USB? Can one just kunload it before suspend? > > g. Only a bit. I believe it is the polling activity of the USB driver that causes the problem, but, if USB drivers are loaded, most systems will never get to the "deeper" sleep levels. My T30 has 3 sleep level of which C2 is only a very modest power savings over C1. C3 is a significant savings, but it is never used if USB devices are present. If you unload the drivers, you should be to lower levels. Take a look at sysctl hw.acpi.cpu for detail and to see how much time is spent in each sleep state. I assume that you can unload the drivers, but my kernel has USB at this time. I do plan on building a kernel without USB and see if unloading is a workable solution. I think it should be. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634