From mboxrd@z Thu Jan 1 00:00:00 1970 From: Len Brown Subject: [RESEND] [PATCH 0/2] Quiet power limit notification Date: Thu, 16 May 2013 17:54:04 -0400 Message-ID: <1368741246-3998-1-git-send-email-lenb@kernel.org> References: <1368625017-6835-1-git-send-email-fenghua.yu@intel.com> Return-path: Received: from mail-ye0-f170.google.com ([209.85.213.170]:33070 "EHLO mail-ye0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751868Ab3EPVyU (ORCPT ); Thu, 16 May 2013 17:54:20 -0400 In-Reply-To: <1368625017-6835-1-git-send-email-fenghua.yu@intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: rjw@sisk.pl Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org [Re-sending for Fenghua, as his e-mail seems to have got lost. In case you receive multiple copies, the patches are unchanged.] thanks, -Len Brown Intel Open Source Technology Center --- Power Limit Notification (X86_FEATURE_PLN) was added in Sandy Bridge to give the OS the option of knowing when the package has reached a configured power threshold. Linux-2.6.36 enabled this feature: 0199114c31798af5b83841b21759b64171060d9b (x86, hwmon: Package Level Thermal/Power: power limit) It enabld the interrupt, and the interrupt hander added to the MCE log and printed to the console: printk(KERN_CRIT "CPU%d: %s power limit notification (total events = %lu) printk(KERN_INFO "CPU%d: %s power limit normal\n" However, these events are quite routine on some systems under some conditions, alarming customers and provoking un-necessary customer support calls. So the MCE log entry was deleted in Linux-3.3: 29e9bf1841e4f9df13b4992a716fece7087dd237 (x86, mce, therm_throt: Don't report power limit and package level thermal throttle events in mcelog) Here we delete the corresponding kernel console messages, and then we disable the interrupt by default -- allowing it to be enabled by cmdline for diagnosis purposes. https://bugzilla.kernel.org/show_bug.cgi?id=36182 This pair of patches applies cleanly back to Linux-3.3. Documentation/kernel-parameters.txt | 2 ++ arch/x86/kernel/cpu/mcheck/therm_throt.c | 43 ++++++++++++++++++++++++++----------------- 2 files changed, 28 insertions(+), 17 deletions(-) [1/2] x86 thermal: Disable power limit notification interrupt by default [2/2] x86 thermal: Delete power-limit-notification console messages