From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark gross Subject: Re: [linux-pm] [PATCH 0/2] RFC: CPU frequency max as PM QoS param Date: Mon, 27 Feb 2012 16:56:30 -0800 Message-ID: <20120228005630.GA15348@envy17> References: <87d39fk2n3.fsf@ti.com> <20120217030453.GA3266@gs62> <87pqd94yeu.fsf@amiettinen-lnx.nvidia.com> <20120221145632.GA2840@envy17> <87linw5aod.fsf@ti.com> <20120225174449.GA17141@envy17> <877gz8wcud.fsf@ti.com> <4F4B9B60.6040501@nvidia.com> Reply-To: markgross@thegnar.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4F4B9B60.6040501@nvidia.com> Sender: cpufreq-owner@vger.kernel.org To: Antti Miettinen Cc: Kevin Hilman , "len.brown@intel.com" , "markgross@thegnar.org" , "cpufreq@vger.kernel.org" , "linux-pm@lists.linux-foundation.org" , "j-pihet@ti.com" List-Id: linux-pm@vger.kernel.org On Mon, Feb 27, 2012 at 04:04:00PM +0100, Antti Miettinen wrote: > To the lists too.. > > On 02/27/2012 04:49 PM, Kevin Hilman wrote: > > mark gross writes: > > > > >> Current QoS settings could be thought of as performance constraints > > >> too. It's just that they determine minimum performance. Adding > > >> constraints for maxium performance is not a big stretch in my mind. > > > > > > Its not a big stretch to me either. I just think its a bit of a hack > > > and there is a bigger more interesting issue getting overlooked. > > > > > > Lastly why not simply make cpufreq thermal aware and talk directly to > > > it if you even need too? > > > > In fact, making a thermal framework "cooling device" that talks directly > > to CPUfreq is already what's being done by the Linaro PMWG folks. > > > > The problem is that CPUfreq only controls the CPU frequency. > > > > There are other devices that could be scaled back to reduce heat as well > > (DSP, and especially GPU), so having a more generic per-device > > constraint interface that can cap the frequency for *any* scalable > > device is a better framework IMO. > > > > It just so happens that pm_qos is already a good per-device constraint > > framework and can easily modified to cap performance as well as request > > a minimum performance. > > > > Kevin ok I'll stop trying to block it. I want to re-do the whole works anyway. If this helps in the mean time then go for it. --mark