From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mahmood Naderan Subject: Re: BIOS and CPU C_states are strange Date: Sat, 20 Jun 2009 11:24:51 +0430 Message-ID: <1acba2fa0906192354i3cb0f2dbp2c8abed6704db3f@mail.gmail.com> References: <1acba2fa0906191006i3cd5a035pf18e096fdb92e27e@mail.gmail.com> <1acba2fa0906191007l4b8d5c17id068d868e6178fb8@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-bw0-f213.google.com ([209.85.218.213]:35818 "EHLO mail-bw0-f213.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751626AbZFTGyu convert rfc822-to-8bit (ORCPT ); Sat, 20 Jun 2009 02:54:50 -0400 Received: by bwz9 with SMTP id 9so2137734bwz.37 for ; Fri, 19 Jun 2009 23:54:51 -0700 (PDT) In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org Hi, > Only simple check value of edx. > Well, unless CPU uses CPUID.5.EDX[31:20], the reserved area. You mean that powertop is not correctly reading the states? Do you mean that the BIOS reports better that the CPU ? -------------------------- *Mahmood Naderan* On Sat, Jun 20, 2009 at 7:26 AM, Edward Shao wrot= e: > > Hi Mahmood, > > So far as I know, if your CPU is Intel, powertop maybe cause a mislea= ding. > Powertop uses CPUID.5.EDX to check CPU supported C states. > According Intel's spec (Intel Processor Identification and the CPUID > Instruction (Application Note 485), a CPU only has > > C0, C1, C2, C3, C4 (prior Core i7) > C0, C1, C2, C6, C7 (Core i7 and subsequent) > > Check with source code of powertop > while (edx) { > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (edx&7) > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0printf("C%i ", i); > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0edx =3D edx >> 4; > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0i++; > =A0 =A0 =A0 =A0} > Only simple check value of edx. > Well, unless CPU uses CPUID.5.EDX[31:20], the reserved area. > > Ps: I does not check AMD's spec. > > Best Regards, > Edward > > > On Sat, Jun 20, 2009 at 1:07 AM, Mahmood Naderan wrote: > > Hi, > > I have run powertop with root permission with both AC and batter po= wers. The > > reported C_States are the same and strange: > > > > mahmood@magma:~$ sudo powertop > > PowerTOP 1.11 =A0 (C) 2007, 2008 Intel Corporation > > > > Collecting data for 5 seconds > > > > Your CPU supports the following C-states : C1 C2 C3 C4 C5 C6 > > Your BIOS reports the following C-states : C1 C2 C6 > > > > Where are C4 and C5? > > > > -------------------------- > > *Mahmood Naderan* > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-acp= i" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at =A0http://vger.kernel.org/majordomo-info.htm= l > > > > > > -- > Best Regards, > Edward -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html