From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antti P Miettinen Subject: Re: [linux-pm] [PATCH 0/2] RFC: CPU frequency max as PM QoS param Date: Wed, 07 Mar 2012 08:38:40 +0200 Message-ID: <8762egyky7.fsf@amiettinen-lnx.nvidia.com> References: <87d39fk2n3.fsf@ti.com> <20120228005630.GA15348@envy17> <87ty2b5mdo.fsf@amiettinen-lnx.nvidia.com> <201203042346.54468.rjw@sisk.pl> <87399lvrxj.fsf@amiettinen-lnx.nvidia.com> <20120306143729.GB29474@redhat.com> Mime-Version: 1.0 Return-path: In-Reply-To: <20120306143729.GB29474@redhat.com> (Dave Jones's message of "Tue, 6 Mar 2012 09:37:29 -0500") Sender: cpufreq-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dave Jones Cc: "Rafael J. Wysocki" , markgross@thegnar.org, Kevin Hilman , Len Brown , cpufreq List , j-pihet , pavel@ucw.cz, Linux PM list Dave Jones writes: > On Tue, Mar 06, 2012 at 02:23:52PM +0200, Antti P Miettinen wrote: [..] > > Dave - any comments about these? > > > > http://thread.gmane.org/gmane.linux.kernel.cpufreq/7794 > > http://thread.gmane.org/gmane.linux.kernel.cpufreq/7797 > > http://thread.gmane.org/gmane.linux.kernel.cpufreq/7800 > > I really dislike how this is exposed to userspace. > How is a user to know whether scaling_max_freq or cpu_freq_max takes > priority ? Given the confusion we already have from users when the > bios_limit enforces limits, giving them two knobs to do the same thing > seems like a bad idea to me. > > I don't see what problem this is solving that you couldn't solve just by > setting scaling_max_freq. > > Dave PM QoS handles multiple clients - the sysfs files are like global variables: there is no arbitration/consolidation for multiple clients. The sysfs files are a sort of override for system administrator whereas the PM QoS is the interface applications should use. --Antti