Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754945AbbLDWfO (ORCPT ); Fri, 4 Dec 2015 17:35:14 -0500 Received: from mail-ig0-f171.google.com ([209.85.213.171]:38702 "EHLO mail-ig0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751665AbbLDWfM (ORCPT ); Fri, 4 Dec 2015 17:35:12 -0500 MIME-Version: 1.0 In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F39F78D9F@ORSMSX114.amr.corp.intel.com> References: <1449188170-3909-1-git-send-email-ashok.raj@intel.com> <20151204143404.GF21177@pd.tnic> <20151204171419.GA4870@otc-brkl-03.jf.intel.com> <20151204165112.GI21177@pd.tnic> <3908561D78D1C84285E8C5FCA982C28F39F78AD9@ORSMSX114.amr.corp.intel.com> <20151204173633.GK21177@pd.tnic> <3908561D78D1C84285E8C5FCA982C28F39F78D9F@ORSMSX114.amr.corp.intel.com> From: Andy Lutomirski Date: Fri, 4 Dec 2015 14:34:52 -0800 Message-ID: Subject: Re: [Patch V0] x86, mce: Ensure offline CPU's don't participate in mce rendezvous process. To: "Luck, Tony" Cc: Borislav Petkov , "Raj, Ashok" , "linux-kernel@vger.kernel.org" , "linux-edac@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1164 Lines: 24 On Fri, Dec 4, 2015 at 9:53 AM, Luck, Tony wrote: >> I don't mean that - I mean the stuff we do before we call >> cpu_is_offline() like ist_enter, this_cpu_inc(mce_exception_count), >> etc. Then we do a whole another bunch of stuff at the "out:" label like >> printk and whatnot which shouldn't run on an offlined CPU. > > ist_enter() is black magic to me. Andy? Would you be worried about executing > ist_{enter,exit}() on a cpu that was once online, but is currently marked offline > by Linux? Offline CPUs are black magic to me. But as long as the CPU works the way that the normal specs say it should, then ist_enter is fair game. In any event, if context tracking blows up on an offline CPU, I'd argue that's a context tracking bug and needs to be fixed. But maybe offlined CPUs are supposed to have all interrupts off (including MCE?) and the argument goes the other way? Dunno. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/