From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joakim Hernberg Subject: Re: CpuFreq Laptop Scaling broken? Date: Mon, 25 Aug 2014 18:58:29 +0200 Message-ID: <20140825185829.2021da78@alchemy.lu> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Harry van Haaren , "Rafael J. Wysocki" , linux-rt-users@vger.kernel.org, Thomas Gleixner , Steven Rostedt To: Viresh Kumar Return-path: Received: from mailsafe.webbplatsen.se ([94.247.172.109]:54625 "EHLO mailsafe.webbplatsen.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932985AbaHYRRr (ORCPT ); Mon, 25 Aug 2014 13:17:47 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, 25 Aug 2014 19:26:03 +0530 Viresh Kumar wrote: > > On 25 August 2014 17:58, Harry van Haaren > > wrote: > > You tried both these as root? Even 'sudo' may not work.. > > > > I haven't seen the rt code since sometime, what tag should I look > > at ? Dont' know how this is supposed to work on a system using the pstate driver, but i have a similar issue: With the realtime patch, but built with CONFIG_PREEMPT__LL=y # uname -r 3.14.12-rt9 # uname -v #1 SMP PREEMPT Mon Aug 25 17:27:37 CEST 2014 # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver intel_pstate # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors performance powersave # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor powersave # echo "performance" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor performance But using i7z, I see no change in behaviour on this cpu, while using the interface in /sys/devices/system/cpu/intel_pstate does seem to work rather well. With the realtime patch enabled CONFIG_PREEMPT_RT_FULL=y # uname -r 3.14.12-rt9-1-rt # uname -v #1 SMP PREEMPT RT Sat Aug 23 04:41:50 CEST 2014 # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver intel_pstate # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors performance powersave # echo "performance" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor bash: echo: write error: Invalid argument # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor powersave I don't if this is normal for the pstate driver, but if one can't change governor, i suppose it shouldn't show one either? -- Joakim