From owner-freebsd-acpi@FreeBSD.ORG Mon Nov 4 17:52:54 2013 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 01926B39 for ; Mon, 4 Nov 2013 17:52:54 +0000 (UTC) (envelope-from kob6558@gmail.com) Received: from mail-pa0-x22d.google.com (mail-pa0-x22d.google.com [IPv6:2607:f8b0:400e:c03::22d]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id CF19426DF for ; Mon, 4 Nov 2013 17:52:53 +0000 (UTC) Received: by mail-pa0-f45.google.com with SMTP id kp14so7228214pab.18 for ; Mon, 04 Nov 2013 09:52:53 -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; bh=bFOfLm3JXAyf+skfKuvQVUKU6WIgU6aqaXU2moYAg8w=; b=CMrDCRI91QMwTrYdo/E8qPYwJ1uW4z5LO6ivRHohmUI5mTU2zcHqXst0+Hjjbh/2KO VF8odRbjTMvLw0/6jOI4b+YXFsQ2Vi7N780r57k7ts9cAOgJd0hDqdIz2UnXMa26vfe8 AzR+0pbdYjGtL2QRNV19p8MvYREgqic2yHfmNhzibfiUvMLSpiXzpCHP2PGi/zs4JZmq ThQk6egvzDDEBrpHHYlLuvjtngKSZwMyj5XfV7/qObpckvpfKg5rdb2iCt1s7yytUY68 zJ6Y2R4rpyM9MAMXTXF8Zhj48GiO8K36ZicN5y981YDTxvdcrcFtyk5Lo2jwJYXoX75k rL8Q== MIME-Version: 1.0 X-Received: by 10.66.144.102 with SMTP id sl6mr18589170pab.96.1383587573436; Mon, 04 Nov 2013 09:52:53 -0800 (PST) Sender: kob6558@gmail.com Received: by 10.67.23.101 with HTTP; Mon, 4 Nov 2013 09:52:53 -0800 (PST) In-Reply-To: References: Date: Mon, 4 Nov 2013 09:52:53 -0800 X-Google-Sender-Auth: L56c-GX7f6wQQgPqY3P3SJAgNdQ Message-ID: Subject: Re: Xeon E5 cpu work in low status From: Kevin Oberman To: =?UTF-8?B?5p2O5qOu?= Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: "freebsd-acpi@freebsd.org" 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 17:52:54 -0000 On Mon, Nov 4, 2013 at 12:46 AM, =E6=9D=8E=E6=A3=AE w= rote: > 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 to 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 by 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 for 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 the 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 other than that, by default, FreeBSD tries to really, really hard to manage power as badly as humanly possible. --=20 R. Kevin Oberman, Network Engineer E-mail: rkoberman@gmail.com