From owner-freebsd-stable@FreeBSD.ORG Wed Mar 21 16:55:37 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 35DCB1065675 for ; Wed, 21 Mar 2012 16:55:37 +0000 (UTC) (envelope-from olivier@gid0.org) Received: from mail-lb0-f182.google.com (mail-lb0-f182.google.com [209.85.217.182]) by mx1.freebsd.org (Postfix) with ESMTP id A67198FC1A for ; Wed, 21 Mar 2012 16:55:35 +0000 (UTC) Received: by lboi15 with SMTP id i15so1298607lbo.13 for ; Wed, 21 Mar 2012 09:55:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding:x-gm-message-state; bh=kb964/ZZcUvDKqxhKKxOV0ZI7l3p6pXMbYLWx64Vfrg=; b=HqDgoucN3JesQgX4b7Pg+DxpOG+1BPk78irs9x7kyWENzr7hoTkI+QA4ACvYV6nwEf 15IqHANu5sQHrwbXBQrnk3yJd77VUXJmKBzZ5iaS6i5zQQ0c2c4RGps+ZBa0HYnDDqI0 ZpktLIneGU0Tx6WzWw1u4pQGh1nAwFF9G9Qn8CTdTSR905snhsIs31/Ha4OhfthcfIyW PdnnmobndnXHS7iRMkmvPztWf653J8bLeDKPR/x9PBJLfkHzMtoCBrc2ByLkajFlit/B WItK8nHuR2RS75UziOrsWcNVpRU7A0LSL3D/dDbs8utZ58I00dSHgRheXH3mhHxp+iu5 CKtw== MIME-Version: 1.0 Received: by 10.112.27.67 with SMTP id r3mr1601857lbg.68.1332348934528; Wed, 21 Mar 2012 09:55:34 -0700 (PDT) Received: by 10.112.144.106 with HTTP; Wed, 21 Mar 2012 09:55:34 -0700 (PDT) In-Reply-To: References: <20120321000058.177F8256@server.theusgroup.com> Date: Wed, 21 Mar 2012 17:55:34 +0100 Message-ID: From: Olivier Smedts To: Kevin Oberman Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Gm-Message-State: ALoCoQn2f9YvESQaZhXTzuuodwleUVUnO2Im91L+MZQE2L/pZ8bj8DjFcfu5UiPsmXb3DNKIRqFb Cc: Matthias Gamsjager , freebsd-stable@freebsd.org, John Subject: Re: powerd and increase in energy need 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: Wed, 21 Mar 2012 16:55:37 -0000 2012/3/21 Kevin Oberman : > If you are trying to reduce power consumption, why are you limiting Cx > states to C2 (which save little) and not C3 (which will save a LOT of > power when the CPU is not heavily loaded). Jumping up on this but I don't know if that's related to his reasons to not use C3. Mine are simple : # sysctl dev.cpu | grep temperature dev.cpu.0.temperature: 39,0C dev.cpu.1.temperature: 40,0C dev.cpu.2.temperature: 36,0C dev.cpu.3.temperature: 36,0C dev.cpu.4.temperature: 41,0C dev.cpu.5.temperature: 41,0C dev.cpu.6.temperature: 36,0C dev.cpu.7.temperature: 36,0C # sysctl hw.acpi.cpu.cx_lowest=3DC3 hw.acpi.cpu.cx_lowest: C2 -> C3 # sysctl dev.cpu | grep temperature dev.cpu.0.temperature: 44,0C dev.cpu.1.temperature: 44,0C dev.cpu.2.temperature: 40,0C dev.cpu.3.temperature: 40,0C dev.cpu.4.temperature: 46,0C dev.cpu.5.temperature: 46,0C dev.cpu.6.temperature: 41,0C dev.cpu.7.temperature: 41,0C # sysctl hw.acpi.cpu.cx_lowest=3DC2 hw.acpi.cpu.cx_lowest: C3 -> C2 # sysctl dev.cpu | grep temperature dev.cpu.0.temperature: 40,0C dev.cpu.1.temperature: 40,0C dev.cpu.2.temperature: 36,0C dev.cpu.3.temperature: 36,0C dev.cpu.4.temperature: 42,0C dev.cpu.5.temperature: 42,0C dev.cpu.6.temperature: 36,0C dev.cpu.7.temperature: 36,0C Only 1-2 seconds between each command, no current load. As you can see, when I engage C3 states, the CPU temperature increases by 4-5=B0C. I expected it to drop. This is with : # sysctl dev.cpu | grep freq dev.cpu.0.freq: 2933 dev.cpu.0.freq_levels: 2933/95 2799/95 2266/75 1733/56 1199/39 # grep perf /etc/rc.conf performance_cx_lowest=3D"C2" performance_cpu_freq=3D"HIGH" # grep hint /boot/loader.conf hint.p4tcc.0.disabled=3D1 hint.acpi_throttle.0.disabled=3D1 # dmesg | head -n 13 | tail -n 9 FreeBSD 9.0-STABLE #0 r233000M: Thu Mar 15 12:30:27 CET 2012 root@zozo.afpicl.lan:/usr/obj/usr/src/sys/CORE amd64 CPU: Intel(R) Core(TM) i7 CPU 860 @ 2.80GHz (2793.04-MHz K8-class = CPU) Origin =3D "GenuineIntel" Id =3D 0x106e5 Family =3D 6 Model =3D 1e St= epping =3D 5 Features=3D0xbfebfbff Features2=3D0x98e3fd AMD Features=3D0x28100800 AMD Features2=3D0x1 TSC: P-state invariant, performance statistics I tried with and without powerd and there's no noticeable difference, so I don't use it. I also tried with and without performance_cpu_freq=3D"HIGH" in /etc/rc.conf (without, dev.cpu.0.freq is 2799 so I don't think TurboBoost is enabled in this case). > If it is due to the system hanging, it is almost certainly because you > have throttling enabled. Throttling, either by the use of TCC (also > called P4TCC) or the older, externally implemented throttling > mechanism, is a BAD BAD THING! I have complained for years about it > being the default. It is intended for thermal control, not power > management. The power savings will be negligible and, in combination > with deep sleep modes (Cx > 2) can and do result in the CPU going into > deep sleep and never waking up. > > You can (and should) disable them in /boot/loader.conf with: > # Disable CPU throttling > hint.p4tcc.0.disabled=3D1 > hint.acpi_throttle.0.disabled=3D1 > > This should greatly reduce the large number of "frequencies" > available, but they will be the ones provided by EST.which really do > reduce power consumption. (I put frequencies in quotation marks > because throttling does not really change the clock speed. It simply > skips 'N' of every 8 clock cycles. Still, compared to C3 and higher, > EST is a minor power savings. > > Just following the recommendations on the power management web page is > the way to go. > -- > R. Kevin Oberman, Network Engineer > E-mail: kob6558@gmail.com > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" --=20 Olivier Smedts=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=A0 _ =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0= =A0 ASCII ribbon campaign ( ) e-mail: olivier@gid0.org=A0 =A0 =A0 =A0 - against HTML email & vCards=A0 X www: http://www.gid0.org=A0 =A0 - against proprietary attachments / \ =A0 "Il y a seulement 10 sortes de gens dans le monde : =A0 ceux qui comprennent le binaire, =A0 et ceux qui ne le comprennent pas."