From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933040AbcBYObA (ORCPT ); Thu, 25 Feb 2016 09:31:00 -0500 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:48986 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932401AbcBYOa6 (ORCPT ); Thu, 25 Feb 2016 09:30:58 -0500 Date: Thu, 25 Feb 2016 14:30:46 +0000 From: Russell King - ARM Linux To: Vineet Gupta Cc: Peter Zijlstra , Will Deacon , "linux-arch@vger.kernel.org" , Marc Zyngier , Frederic Weisbecker , lkml , Noam Camus , arcml Subject: Re: Interesting csd deadlock on ARC Message-ID: <20160225143046.GR19428@n2100.arm.linux.org.uk> References: <56C6BA82.1060909@synopsys.com> <56CBEC66.2030401@synopsys.com> <20160223095824.GH6356@twins.programming.kicks-ass.net> <56CD36CD.2080303@synopsys.com> <20160225140654.GL6357@twins.programming.kicks-ass.net> <56CF0E6B.5020903@synopsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56CF0E6B.5020903@synopsys.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 25, 2016 at 07:53:39PM +0530, Vineet Gupta wrote: > But then ARM CONFIG_SMP on UP hardware will still crap out because there > is no way to send IPI to self. Same as the bug in above discussion. I'm > surprised they way ARM guys worked around it. We haven't worked around it - the code which provoked the oops that was seen (in the cpufreq code) was changed not to call it, which has the effect of making the problem "go away", at least for now. We still have the problem that if it does get called on UP, it'll blow up - and I don't see any point in complicating the code for something that never happens right now. -- RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.