From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [PATCH 69/70] ACPI : Create "idle=nomwait" bootparam Date: Fri, 20 Jun 2008 08:02:09 -0700 Message-ID: <20080620080209.56ccd618.randy.dunlap@oracle.com> References: <1213947852-10924-1-git-send-email-lenb@kernel.org> <5ffc8862cc917ae5107049f3c5fd549fb6c19cac.1213947350.git.len.brown@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from rgminet01.oracle.com ([148.87.113.118]:28407 "EHLO rgminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756167AbYFTPLt (ORCPT ); Fri, 20 Jun 2008 11:11:49 -0400 In-Reply-To: <5ffc8862cc917ae5107049f3c5fd549fb6c19cac.1213947350.git.len.brown@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Len Brown Cc: linux-acpi@vger.kernel.org, Zhao Yakui , Li Shaohua , Len Brown On Fri, 20 Jun 2008 03:44:11 -0400 Len Brown wrote: > From: Zhao Yakui > > Add the boot option of "idle=nomwait" to disable Mwait for CPU C-states. > If the boot option of "idle=nomwait" is added , Linux should not > use mwait for cpu idle even when the mwait is supported. In such case the > C2C3_FFH access mode will be disabled. > > http://bugzilla.kernel.org/show_bug.cgi?id=10807 > > Signed-off-by: Zhao Yakui > Signed-off-by: Li Shaohua > Signed-off-by: Len Brown > --- > Documentation/kernel-parameters.txt | 4 +++- > arch/ia64/kernel/process.c | 2 ++ > arch/x86/kernel/process.c | 14 ++++++++++++++ > drivers/acpi/processor_core.c | 12 ++++++++++++ > include/asm-ia64/processor.h | 1 + > include/asm-x86/processor.h | 1 + > 6 files changed, 33 insertions(+), 1 deletions(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 1623c2f..39baaba 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -785,7 +785,7 @@ and is between 256 and 4096 characters. It is defined in the file > See Documentation/ide/ide.txt. > > idle= [X86] > - Format: idle=poll or idle=mwait, idle = halt > + Format: idle=poll or idle=mwait, idle = halt, idle=nomwait idle=halt [no spaces] > Poll forces a polling idle loop that can slightly improves the performance > of waking up a idle CPU, but will use a lot of power and make the system > run hot. Not recommended. > @@ -795,6 +795,8 @@ and is between 256 and 4096 characters. It is defined in the file > as idle=poll. > idle = halt . Halt is forced to be used for CPU idle. idle=halt . (no spaces allowed in command line parsing AFAIK) > In such case C2/C3 won't be used again. > + idle = nomwait. disable Mwait for CPU C-state. > + In such case C2C3_FFH access mode will be disabled. > > ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem > Claim all unknown PCI IDE storage controllers. --- ~Randy Linux Plumbers Conference, 17-19 September 2008, Portland, Oregon USA http://linuxplumbersconf.org/