From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 77771] Intel P-State: Constantly changing CPU frequencies on idle system. Date: Mon, 16 Jun 2014 19:15:58 +0000 Message-ID: References: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: cpufreq-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: cpufreq@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=77771 --- Comment #5 from Michael Long --- Thanks for the hint about the turbostat utility. Without starting a desktop environment I got similar stats, all frequencies are very close around the lowest state. Logged into KDE showed different results. Eventually I found the cause of those high clocks: A superkaramba desktop-widget. This widget basically does a grep on /proc/cpuinfo and checks the load internally each second. Disabling this widget gets the clock down. The same behavior can be reproduced just by running "for i in {1..99}; do grep MHz /proc/cpuinfo; sleep 1; done". Admittedley this might be a typical layer8-problem, however why is a simple grep every second pounding the CPU so hard that it remains in higher clocks, even in turbo mode? Especially when it didn't before the patch or just using plain old acpi-cpufreq. If this is still just expected behavior sorry for the unnecessary noise. -- You are receiving this mail because: You are the assignee for the bug.