From owner-freebsd-acpi@FreeBSD.ORG Mon Nov 4 18:00:49 2013 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 7DE7DC1D for ; Mon, 4 Nov 2013 18:00:49 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-qa0-x22c.google.com (mail-qa0-x22c.google.com [IPv6:2607:f8b0:400d:c00::22c]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 3F380272E for ; Mon, 4 Nov 2013 18:00:49 +0000 (UTC) Received: by mail-qa0-f44.google.com with SMTP id f11so425001qae.17 for ; Mon, 04 Nov 2013 10:00:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=R4jbOuGCuLO63nmIdRgQPoj5aWrFtogDwyJpQf4SsLM=; b=PHWj7akCUuhkD3I3MtfccLAl64PGxKz3w4DqDo8p3d5AlHFK5Ur/BEzNpk5T09r6pu QxI2alvqJYfORtaHJnqmtvVM7PYF1v0iosMmTNyKw2oyZH6bv0wjEK7RidC0ZCSNjpmN Z+lM0hxi24ByhcWjoGV2l/d0CvbQb+LmUd5Cmn00QBW0LzHB4Aj5db4gRAmNpCyUiTga pZWCeLxti3nnWAiPhCqGQ23dMUpXtAG7vLKzM5Wi6Tz0UbofBMkUk+E+v+8k/bk5wBgg 7Tq9LnSGB9Zd+LZTcxqJCEvQ7oUm/hhXSXmn5wdlzCQoowA+ASjXKfyC1VYbjjrYl1YQ v8JQ== MIME-Version: 1.0 X-Received: by 10.49.59.115 with SMTP id y19mr23851629qeq.8.1383588048455; Mon, 04 Nov 2013 10:00:48 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.224.207.66 with HTTP; Mon, 4 Nov 2013 10:00:48 -0800 (PST) In-Reply-To: References: Date: Mon, 4 Nov 2013 10:00:48 -0800 X-Google-Sender-Auth: HNOKVNMmQvx5zrl8GnCOHVdSm0I Message-ID: Subject: Re: Xeon E5 cpu work in low status From: Adrian Chadd To: Kevin Oberman Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-acpi@freebsd.org" , =?UTF-8?B?5p2O5qOu?= X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Nov 2013 18:00:49 -0000 A lot of us think this. The question is .. who's going to fix it? :-) -adrian On 4 November 2013 09:52, Kevin Oberman wrote: > On Mon, Nov 4, 2013 at 12:46 AM, =E6=9D=8E=E6=A3=AE = wrote: > >> hi,all: >> the cpu of my machine is : Intel(R) Xeon(R) CPU E5-2643 0 @ >> 3.30GHz. >> >> after a reboot. The cpu freq is : sysctl dev.cpu.0.freq >> dev.cpu.0.freq: 1200 >> >> i didn't set any power savings config in rc.conf. >> >> How can i fix this? >> > > It's not clear what is broken. Is the server busy? Is there some reason t= o > expect it to be running at full clock-rate? > > What is the content of dev.cpu.0.freq_levels? > > By default, FreeBSD runs powerd and that will, by default, throttle back > the clock when the system is not busy. I think that this is a bad thing., > but it is not a bug. It's by design. I really think, based on my own > testing, research and a major NSF computer center (SDSC), and work done b= y > mav@ which can be found on the FreeBSD wiki ( > https://wiki.freebsd.org/TuningPowerConsumption), those "power management= " > tools are broken by design a they are actually there for thermal control, > not power management and are, at best, break-even, and in most cases are > actually a loser in both power savings and system performance. (There are= a > very few edge cases where they can be beneficial, but as a side effect fo= r > very specific loads under fairly unusual circumstances.) > > To turn off these (mis)features, add the following to /boot/loader.conf: > # Disable CPU throttling > hint.p4tcc.0.disabled=3D1 > hint.acpi_throttle.0.disabled=3D1 > > > All real power management is through the use of EST and CPU sleep (CX) > states. These can provide a big power win at minimal performance impact. > Unfortunately CX states and throttling lay very badly together, probably > because processor designers don't think that TCC and throttling are for > power management, so are not an issue. > > For reasons that have always baffled me, rather than disable the > inappropriate use of thermal management as power management, we disable t= he > most effective power management tools by default. > performance_cx_lowest=3D"HIGH" # Online CPU idle state > economy_cx_lowest=3D"HIGH" # Offline CPU idle state > > Even the comments are confusing: what do "Online" and "Offline" mean? > Offline means running on battery and online means AC power. > > In any case, it's not clear that there is any issue with your system othe= r > than that, by default, FreeBSD tries to really, really hard to manage pow= er > as badly as humanly possible. > > > -- > R. Kevin Oberman, Network Engineer > E-mail: rkoberman@gmail.com > _______________________________________________ > freebsd-acpi@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-acpi > To unsubscribe, send any mail to "freebsd-acpi-unsubscribe@freebsd.org"