Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752805AbWKBKVO (ORCPT ); Thu, 2 Nov 2006 05:21:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752806AbWKBKVO (ORCPT ); Thu, 2 Nov 2006 05:21:14 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:47250 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S1752805AbWKBKVO (ORCPT ); Thu, 2 Nov 2006 05:21:14 -0500 Date: Thu, 2 Nov 2006 11:20:59 +0100 From: Pavel Machek To: Zachary Amsden Cc: Chris Wright , akpm@osdl.org, ak@muc.de, Rusty Russell , Jeremy Fitzhardinge , linux-kernel@vger.kernel.org, virtualization@lists.osdl.org Subject: Re: [PATCH 4/7] Allow selected bug checks to be skipped by paravirt kernels Message-ID: <20061102102059.GB1990@elf.ucw.cz> References: <20061029024504.760769000@sous-sol.org> <20061029024606.496399000@sous-sol.org> <20061101121753.GA2205@elf.ucw.cz> <45492CBC.8020501@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45492CBC.8020501@vmware.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1196 Lines: 31 Hi! > >>Allow selected bug checks to be skipped by paravirt kernels. The two most > >>important are the F00F workaround (which is either done by the hypervisor, > >>or not required), and the 'hlt' instruction check, which can break under > >>some hypervisors. > >> > > > >How can hlt check break? It is hlt;hlt;hlt, IIRC, that looks fairly > >innocent to me. > > > > Not if you use tickless timers that don't generate interrupts to unhalt > you, or if you delay ticks until the next scheduled timeout and you > haven't yet scheduled any timeout. Both are likely in a hypervisor. Well.. but you are working around problem, instead of fixing it. Tickless kernels are possible on normal machines, too. Please fix it properly... probably by requesting timer 10msec in advance or something. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - 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/