From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932923AbcKIPiM (ORCPT ); Wed, 9 Nov 2016 10:38:12 -0500 Received: from mail.skyhub.de ([78.46.96.112]:48584 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752922AbcKIPiK (ORCPT ); Wed, 9 Nov 2016 10:38:10 -0500 Date: Wed, 9 Nov 2016 16:38:07 +0100 From: Borislav Petkov To: Sebastian Andrzej Siewior Cc: "Luck, Tony" , linux-kernel@vger.kernel.org, rt@linutronix.de, linux-edac@vger.kernel.org, x86@kernel.org, Thomas Gleixner Subject: Re: [PATCH 22/25] x86/mcheck: Do the init in one place Message-ID: <20161109153807.7mv7b5f4oqfijq2h@pd.tnic> References: <20161103145021.28528-1-bigeasy@linutronix.de> <20161103145021.28528-23-bigeasy@linutronix.de> <20161107184532.xj6wzdjlzwhshcmf@pd.tnic> <20161107185524.GA2536@intel.com> <20161107201224.7xazmhgm7bogkrw5@pd.tnic> <20161108092302.wraci5m2cxqozlew@pd.tnic> <20161109142221.3r6xwhkxbckuv3bh@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20161109142221.3r6xwhkxbckuv3bh@linutronix.de> User-Agent: NeoMutt/20161014 (1.7.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 09, 2016 at 03:22:21PM +0100, Sebastian Andrzej Siewior wrote: > I want to get rid of non-symmetrical part and the arch hook which should > be part of the hp notifier itself. I wouldn't be too much afraid about > the when point in time when the notifier runs: It is the *first* > notifier that will be invoked on the target CPU. This is only a few > lines after the old hook. Nothing else long delaying should be invoked. So I'm not sure *everything* mcheck_cpu_init() does should be in hotplug and toggle on and off. For example, we should set CR4.MCE once during init and that's it. Not turn it on and off. It would be pretty pointless IMO. That's why the hotplug callback mce_disable_cpu() doesn't fiddle with CR4 - it only clears the bits in MCi_CTL. And I think we should remain that way. The initial, one-time enabling of MCE features per core should be done only once per boot and that's it. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.