From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominik Brodowski Subject: Re: pm qos and cpufreq interaction [Was: pm qos infrastructure and interface] Date: Thu, 25 Oct 2007 20:54:28 +0200 Message-ID: <20071025185428.GA1692@isilmar.linta.de> References: <20071004215139.GA20078@linux.intel.com> <20071023180343.GA2624@isilmar.linta.de> <20071024212150.GA17504@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20071024212150.GA17504@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Mark Gross Cc: linux-pm@lists.linux-foundation.org List-Id: linux-pm@vger.kernel.org Hi Mark, On Wed, Oct 24, 2007 at 02:21:50PM -0700, Mark Gross wrote: > > On Thu, Oct 04, 2007 at 02:51:39PM -0700, Mark Gross wrote: > > What about cpu_throughput{_min,_max}, as being something considered to be > > proportional to the CPU frequency? This way, the cpufreq policy notifiers > > might be able to utilize the pm_qos infrastructure; but maybe even also the > > userspace interface (at least the min freq/max freq one)... Haven't thought > > this through, but maybe you (or someone else) has. > > I've only thought it though enough to choose to avoid cpufreq > interactions. > > Sadly core frequency is not proportional to throughput on X86 > processors. I don't know how one would reliably quantify cpu throughput > in this context, other than defining latencies. Well it's not exactly throughput, but the CPU frequency surely has an influence on it and also affects the quality of the service provided... > I could see something like this to prevent cpufreq throttling at bad > times, but how common of an issue is this any more? Hopefully none :) I was just wondering whether this generalization would make sense in the big scheme of things (i.e. grand plan of unified power management)... > Its good to hear from you. Will you be at the ELC conference in Linz > next week? Unfortunately not. Best, Dominik