Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757297AbYCKNYc (ORCPT ); Tue, 11 Mar 2008 09:24:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752849AbYCKNYY (ORCPT ); Tue, 11 Mar 2008 09:24:24 -0400 Received: from one.firstfloor.org ([213.235.205.2]:34753 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752206AbYCKNYY (ORCPT ); Tue, 11 Mar 2008 09:24:24 -0400 Date: Tue, 11 Mar 2008 14:26:16 +0100 From: Andi Kleen To: Zdenek Kabelac Cc: Andi Kleen , Ingo Molnar , tglx@linutronix.de, linux-kernel@vger.kernel.org, jkosina@suse.cz Subject: Re: [PATCH REPOST] Run IST traps from user mode preemptive on process stack Message-ID: <20080311132616.GH18917@one.firstfloor.org> References: <20080311012432.GA28576@basil.nowhere.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1410 Lines: 33 > I'm not sure whether this is good or bad sign - but with this patch > you have posted, > I do not have to wait in qemu for minutes to get the 'busy-loop' - I > get the exact same loop almost instantly when I start disk read of LV > partition and running my simple module insertion testcase. Hmm, my fix was intended to fix a gdb problem. Or rather the gdb problem was already fixed by disabling some functionality and with this patch the functionality would be reenabled again. If it fixed a qemu problem too that's great but was unintended on my part. In fact it is a little worrying because there should be no user visible change. Can you double check by unapply/test/reapply/test the patch really makes a difference? > > > This patch changes these traps instead to always switch > > to the process stack when the trap originated from user mode. > > For kernel traps it keeps running non preemptive on the IST stack > > because that is much safer (e.g. to still get nmi watchdog events > > out even when the process stack is corrupted) > > > > So what should I check to get fixed my problem in qemu ? I don't know. Someone has to debug it. -Andi -- 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/