From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [PATCH] CPU_IDLE: Documentation for CPU_IDLE Date: Tue, 12 Feb 2008 20:36:49 -0800 Message-ID: <47B273E1.70807@oracle.com> References: <20080212015545.GA1691@linux-os.sc.intel.com> <20080212084605.28f0d3f3.randy.dunlap@oracle.com> <20080213011552.GA7319@linux-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rgminet01.oracle.com ([148.87.113.118]:34186 "EHLO rgminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753018AbYBMEhW (ORCPT ); Tue, 12 Feb 2008 23:37:22 -0500 In-Reply-To: <20080213011552.GA7319@linux-os.sc.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Venki Pallipadi Cc: Len Brown , linux-acpi@vger.kernel.org Venki Pallipadi wrote: > Updated reflecting Randy's comments. > > Thanks, > Venki > > > Documentation for cpuidle infrastructure. This patch was submitted once > a while back. But, somehow got dropped or never made it upstream. > > Resending with updates. > > Signed-off-by: Venkatesh Pallipadi > > Index: linux-2.6.25-rc/Documentation/cpuidle/core.txt > =================================================================== > --- /dev/null > +++ linux-2.6.25-rc/Documentation/cpuidle/core.txt > @@ -0,0 +1,24 @@ > + > + Supporting multiple CPU idle levels in kernel > + > + cpuidle > + > +General Information: > + > +Various CPUs today support multiple idle levels that are differentiated > +by varying exit latencies and power consumption during idle. > +cpuidle is a generic in-kernel infrastructure that separates > +idle policy (governor) from idle mechanism (driver) and provides a > +standardized infrastructure to support independent development of > +governors and drivers. > + > +cpuidle resides under drivers/cpuidle. > + > +Boot options: > +"cpuidle_sysfs_switch" > +enables current_governor interface in /sys/devices/system/cpu/cpuidle/. s#cpuidle/.#cpuidle/,# > +which can be used to switch governors at run time. This boot option > +is meant for developer testing only. In normal usage, kernel picks the > +best governor based on governor ratings. > +SEE ALSO: sysfs.txt in this directory. Thanks. -- ~Randy