From owner-cvs-all Tue Jan 14 19:16:43 2003 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7EDE537B401; Tue, 14 Jan 2003 19:16:41 -0800 (PST) Received: from canning.wemm.org (canning.wemm.org [192.203.228.65]) by mx1.FreeBSD.org (Postfix) with ESMTP id C67C243F7C; Tue, 14 Jan 2003 19:16:39 -0800 (PST) (envelope-from peter@wemm.org) Received: from wemm.org (localhost [127.0.0.1]) by canning.wemm.org (Postfix) with ESMTP id A88182A89E; Tue, 14 Jan 2003 19:16:39 -0800 (PST) (envelope-from peter@wemm.org) X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Josef Karthauser Cc: Andrew Gallatin , John Baldwin , Wilko Bulte , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org, Nate Lawson Subject: Re: cvs commit: src/sys/dev/acpica acpi_cpu.c In-Reply-To: <20030115011342.GA5983@genius.tao.org.uk> Date: Tue, 14 Jan 2003 19:16:39 -0800 From: Peter Wemm Message-Id: <20030115031639.A88182A89E@canning.wemm.org> Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Josef Karthauser wrote: > > --PNTmBPCT7hxwcZjr > Content-Type: text/plain; charset=us-ascii > Content-Disposition: inline > Content-Transfer-Encoding: quoted-printable > > On Tue, Jan 14, 2003 at 03:00:57PM -0800, Peter Wemm wrote: > > >=20 > > FWIW, we see a (measured) difference of about 50W on 2.2GHz P4's simply by > > turning machdep.cpu_idle_hlt on and off. I expect the clock throttling > > would make similar differences. For 1U rack-mount systems (especially in > > California) this is a Big Deal. > >=20 > > Which way's the way to reduce the power consumption? I would guess > 'machdep.cpu_idle_hlt=3D1', but as that appears to be the default I > thought I'd ask. Yes, it is the default, but for uniprocessor only. Sorry for not being clear. On SMP, machdep.cpu_idle_hlt=0 since we do not do resched IPI's to wake up the halted cpus, so this is a slight performance loss in mny cases. What I was trying to point out was that the power consumption of P4's varies a *HUGE* amount depending on what it is doing. Clock tweaking should have similar effects. > Joe > --=20 > Josef Karthauser (joe@tao.org.uk) http://www.josef-k.net/ > FreeBSD (cvs meister, admin and hacker) http://www.uk.FreeBSD.org/ > Physics Particle Theory (student) http://www.pact.cpes.sussex.ac.uk/ > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D An eclectic mix of fact an= > d theory. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > --PNTmBPCT7hxwcZjr > Content-Type: application/pgp-signature > Content-Disposition: inline > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.2.1 (FreeBSD) > > iEYEARECAAYFAj4ktcUACgkQXVIcjOaxUBYeLwCdEVgb4IjnDM0XTmH7cpcojQir > SfIAn2olNbW4mFQv8aXIRrWuXsA4t2bB > =TcBn > -----END PGP SIGNATURE----- > > --PNTmBPCT7hxwcZjr-- > Cheers, -Peter -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message