From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mahmood Naderan Subject: Re: BIOS and CPU C_states are strange Date: Sun, 21 Jun 2009 14:32:55 +0430 Message-ID: <1acba2fa0906210302x19c31974md75c72b7a171c852@mail.gmail.com> References: <1acba2fa0906191006i3cd5a035pf18e096fdb92e27e@mail.gmail.com> <1acba2fa0906191007l4b8d5c17id068d868e6178fb8@mail.gmail.com> <1acba2fa0906192354i3cb0f2dbp2c8abed6704db3f@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]:47359 "EHLO mail-bw0-f213.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752184AbZFUKCx convert rfc822-to-8bit (ORCPT ); Sun, 21 Jun 2009 06:02:53 -0400 Received: by bwz9 with SMTP id 9so2544323bwz.37 for ; Sun, 21 Jun 2009 03:02:55 -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, 1- where can I find powertop source code? 2- what is the name of intel utility in windows as you said? -------------------------- *Mahmood Naderan* On Sun, Jun 21, 2009 at 2:19 PM, Edward Shao wrote= : > Hi~ > It's all depended on how utility to interpret raw information (both > information reported by CPU or BIOS). > You can check source code of powertop for detail information. > For BIOS part, powertop checks value of mwait hint register reported > by ACPI _CST method. > > As my experience, powertop will cause a misleading sometimes, > especially for new Intel CPU. > For example: > BIOS engineer said they followed Intel BIOS porting guide to report a= n > accuracy C-state (C6) information via ACPI _CST method. > However powertop said BIOS only reports C3. (but Intel utility under > Windows said CPU can enter C6). > > Best Regards, > Edward > > On Sat, Jun 20, 2009 at 2:54 PM, Mahmood Naderan wrote: >> 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 w= rote: >>> >>> Hi Mahmood, >>> >>> So far as I know, if your CPU is Intel, powertop maybe cause a misl= eading. >>> Powertop uses CPUID.5.EDX to check CPU supported C states. >>> According Intel's spec (Intel Processor Identification and the CPUI= D >>> 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 = powers. 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-a= cpi" in >>> > the body of a message to majordomo@vger.kernel.org >>> > More majordomo info at =A0http://vger.kernel.org/majordomo-info.h= tml >>> > >>> >>> >>> >>> -- >>> Best Regards, >>> Edward >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-acpi= " in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at =A0http://vger.kernel.org/majordomo-info.html >> > > > > -- > 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