Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933667Ab1EXVmG (ORCPT ); Tue, 24 May 2011 17:42:06 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:52358 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756665Ab1EXVmB (ORCPT ); Tue, 24 May 2011 17:42:01 -0400 Date: Tue, 24 May 2011 23:41:39 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Linus Torvalds , Tony Luck , Borislav Petkov , "linux-kernel@vger.kernel.org" , "Huang, Ying" , Andi Kleen , Borislav Petkov , Andrew Morton , Mauro Carvalho Chehab Subject: Re: [RFC 0/9] mce recovery for Sandy Bridge server Message-ID: <20110524214139.GP27634@elte.hu> References: <4ddad79317108eb33d@agluck-desktop.sc.intel.com> <20110524034023.GB25230@elte.hu> <987664A83D2D224EAE907B061CE93D5301D5D0595B@orsmsx505.amr.corp.intel.com> <20110524173326.GA7635@gere.osrc.amd.com> <1306272274.2497.73.camel@laptop> <1306273062.2497.80.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1306273062.2497.80.camel@laptop> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1114 Lines: 30 * Peter Zijlstra wrote: > On Tue, 2011-05-24 at 14:30 -0700, Linus Torvalds wrote: > > On Tue, May 24, 2011 at 2:24 PM, Peter Zijlstra wrote: > > > > > > Right, so you can't do things like that from NMI context, but what perf > > > can do is raise a self-IPI and continue from IRQ context (question for > > > the HW folks, can there be cycles between the NMI iret and IRQ assert > > > from whatever context was before the NMI hit?) > > > > Of course there can be - the code where the NMI hit may have > > interrupts disabled. > > D'0h yes of course!.. > > Then I can't immediately see a way to stop a thread dead in its tracks. > Userspace yes, but not kernel-space. It's a best-effort thing: run proper kernel code (hardirq context) as soon as possible - but obviously not sooner than that! :-) Thanks, Ingo -- 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/