From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753702AbbEHRPM (ORCPT ); Fri, 8 May 2015 13:15:12 -0400 Received: from mail-pd0-f178.google.com ([209.85.192.178]:34257 "EHLO mail-pd0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267AbbEHRPK (ORCPT ); Fri, 8 May 2015 13:15:10 -0400 From: Kevin Hilman To: Simon Horman Cc: Thomas Gleixner , linux-sh@vger.kernel.org, Peter Zijlstra , Magnus Damm , LKML , Ingo Molnar , LAK Subject: Re: Possible regression due to "hrtimer: Get rid of hrtimer softirq" References: <20150507111711.GA17448@verge.net.au> <20150507132543.GA14889@verge.net.au> Date: Fri, 08 May 2015 10:14:52 -0700 In-Reply-To: <20150507132543.GA14889@verge.net.au> (Simon Horman's message of "Thu, 7 May 2015 22:25:43 +0900") Message-ID: <7hvbg3gfeb.fsf@deeprootsystems.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Simon Horman writes: > Hi Thomas, > > On Thu, May 07, 2015 at 02:35:59PM +0200, Thomas Gleixner wrote: >> On Thu, 7 May 2015, Simon Horman wrote: >> > ------------[ cut here ]------------ >> > kernel BUG at kernel/irq_work.c:135! >> >> BUG_ON(!irqs_disabled()); >> >> So something enables interrupts in the periodic tick handling >> machinery. Seems you have high resolution timers disabled, but nohz >> enabled. And that code path has a local_irq_disable/enable pair which >> causes havoc. Patch below. > > Thanks for your quick response. I have been able to confirm that > when applied on top of next-20150507 the problem I observed no longer > manifests. I have successfully tested it on all the boards > where I previously observed a problem. > > If you are planning to formally submit the patch below feel free to add: > > Tested-by: Simon Horman FWIW, I confirmed this fixed a boot hang on my kzm9d in next-20150507 also. Tested-by: Kevin Hilman