From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932484AbdBVNTm (ORCPT ); Wed, 22 Feb 2017 08:19:42 -0500 Received: from mout.gmx.net ([212.227.17.22]:64101 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932120AbdBVNTf (ORCPT ); Wed, 22 Feb 2017 08:19:35 -0500 Message-ID: <1487769542.4487.2.camel@gmx.de> Subject: Re: 9908859acaa9 cpuidle/menu: add per CPU PM QoS resume latency consideration From: Mike Galbraith To: Peter Zijlstra Cc: Alex Shi , LKML Date: Wed, 22 Feb 2017 14:19:02 +0100 In-Reply-To: <20170222131218.GS6515@twins.programming.kicks-ass.net> References: <1487768197.27533.5.camel@gmx.de> <20170222131218.GS6515@twins.programming.kicks-ass.net> Content-Type: text/plain; charset="us-ascii" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:tuR8yJ2p27ZXkWhwjz6JkefyvbA7C5D5MCdr7I006S4EI1jolak vNaeOLMIJnGLzF+pnlCztCjoMWLmtidm5tirJObF0u5J7ji7HMli56HznrPTE7GB1R7eUV4 m6HQgiRKFIahVfiryftAqSYFtFxxm6FYn78gbvOA++7H2Nynz8o1NFaxIxA8Cn16knkS4qI fYs+JJByPywBzySocFDnA== X-UI-Out-Filterresults: notjunk:1;V01:K0:RZPTf8IuWQg=:iRh+1uMXAMToxfYWEAg/V8 msmX1zLLRlNBVDHketHFl+qC1cDcV5hlQyInY2fzZ8aV9M5PvmoHuFOYL2jkrKfDgax8+pb+d WDO9fCIzcGFeQdQbqNPHX6ITP4pm1nbqtT0stURXBkBjor8RDYTNg5JXKO+Z7ozR+5vkbOWBt +4vHZd2ueVGg0CdsLLUNmJoWpWtD1rdm0+4GsQCl4raNSrA3bgKRItEbtkcjW5VPAIpXx1Q1Y NN0Kpmb8MmXLcNzfahVLwHztGinddW2jp68hfIg+18g5bFcdC8cZ43O+YkYOwf2DT4MRbuPri BrL2GUMHMMDJNBGswYK5EASPiXzzjTD/T6Uq/7hXcnA0WTqwPgvabDcHGOt2gFQtv5mJ/6yeU WX6Pt1dU9z45Cfkv3P8Mf8y4JkfxlMseyf8amDXCw/zzB/p6fuFFlAyeNX6/mdddtY7b5oOy+ e6EcbnwZcMk+2zn6kKisNrikJQ/iDZSPIC17S+zbYwOJcfeZWcERO4KFHWEuGIYGiyhkB0E2v kq7HPg4wvqd7YD5J+zg7zdPi6kg374bnbqB5QUsiUX1joeVOVdxFR9c8BekyPcmlEhoDy0nDh GCQOIa9KQHuQMm/4ZS0aHMadb3XdO7Yf3+cuRk0Glx4/TRSu837wrScG+eelKWLyqJpP+Ydab PaUQVHO4rK4STbTL1zbmPeDv0L0wrScqDYbalseAEjf1QD5ZMwkPYlS8n/e9t8xXhqmN2I+oN HFwIFyA/78yoFPSKjml7LYK8n3fIQhNu/uUGtAMVQOD9hZnMNx29dIOWhUW7C1jqEfyMmQB9W O1JJf+QKuksrAW/EyzAa+rG/gZncRGXnUx7pHzlDsJrHgxBzEiM0FzvliiUpOo6htrOhl4+kK DiVEc84XIvNA+NxX06jj/Tyr73VK+Jujti1gYF4qs1s9hK8Lw1sHre8C2iO+VKahvdA/lMn7v psqZ98ZdCwwLTZU/F+huJiqPBQSfFf5eZs/IYNYFc4VvD3UWZmyPz2GN1cFBvMSuyxzFabQKj 0X/JzFl7S435BpJDXWfeupg= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2017-02-22 at 14:12 +0100, Peter Zijlstra wrote: > On Wed, Feb 22, 2017 at 01:56:37PM +0100, Mike Galbraith wrote: > > Hi, > > > > Do we really need a spinlock for that in the idle loop? > > Urgh, that's broken on RT, you cannot schedule the idle loop. That's what made me notice the obnoxious little bugger. [ 77.608340] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:995 [ 77.608342] in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 [ 77.608343] INFO: lockdep is turned off. [ 77.608344] irq event stamp: 59222 [ 77.608353] hardirqs last enabled at (59221): [] rcu_idle_exit+0x2f/0x50 [ 77.608362] hardirqs last disabled at (59222): [] do_idle+0x9a/0x290 [ 77.608372] softirqs last enabled at (0): [] copy_process.part.34+0x5f1/0x22a0 [ 77.608374] softirqs last disabled at (0): [< (null)>] (null) [ 77.608374] Preemption disabled at: [ 77.608383] [] schedule_preempt_disabled+0x22/0x30 [ 77.608387] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W E 4.11.0-rt9-rt #163 [ 77.608389] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0056.R01.1409242327 09/24/2014 [ 77.608390] Call Trace: [ 77.608399] dump_stack+0x85/0xc8 [ 77.608405] ___might_sleep+0x15d/0x260 [ 77.608409] rt_spin_lock+0x24/0x80 [ 77.608419] dev_pm_qos_read_value+0x1e/0x40 [ 77.608424] menu_select+0x56/0x3e0 [ 77.608426] ? rcu_eqs_enter_common.isra.40+0x9d/0x160 [ 77.608435] cpuidle_select+0x13/0x20 [ 77.608438] do_idle+0x182/0x290 [ 77.608445] cpu_startup_entry+0x48/0x50 [ 77.608450] start_secondary+0x133/0x160 [ 77.608453] start_cpu+0x14/0x14