From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [PATCH][RT] x86: Fix an RT MCE crash Date: Thu, 30 Jun 2016 19:26:11 +0200 Message-ID: <20160630172611.GC3932@pd.tnic> References: <1467293089-27656-1-git-send-email-minyard@acm.org> <20160630094301.22d32ec1@gandalf.local.home> <5775316F.2020102@acm.org> <20160630115101.6337c395@gandalf.local.home> <20160630160128.GA4365@pd.tnic> <3908561D78D1C84285E8C5FCA982C28F3A14CDB9@ORSMSX114.amr.corp.intel.com> <57754B71.2000108@acm.org> <20160630170134.GA3932@pd.tnic> <57755449.7070302@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: "Luck, Tony" , Steven Rostedt , "linux-rt-users@vger.kernel.org" , Corey Minyard To: Corey Minyard Return-path: Received: from mail.skyhub.de ([78.46.96.112]:43710 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751536AbcF3RhE (ORCPT ); Thu, 30 Jun 2016 13:37:04 -0400 Content-Disposition: inline In-Reply-To: <57755449.7070302@acm.org> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Thu, Jun 30, 2016 at 12:18:01PM -0500, Corey Minyard wrote: > This is on 3.10-rt with PREEMPT_RT enabled. It appears that from 3.18-rt > and later it has code like the change I have proposed, so it does not crash. > > I could add a something to see if the interrupt is coming in early to > 4.6-rt, > is that what you are looking for? Actually, I'd like to know first whether the unpatched upstream kernel - not -rt - is crashing. And then 4.6-rt. Because from looking at your splat, you're getting a thresholding interrupt the moment you enable the local APIC and from staring at the MCE code upstream, I think we should be prepared for that scenario. AFAICT, both -rt and upstream should handle that case just fine and I'm guessing upstream was fixed at some point and -rt grew another fix which is probably not needed and it should take the upstream one instead... -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.