Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754108Ab3JISRQ (ORCPT ); Wed, 9 Oct 2013 14:17:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48686 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752215Ab3JISRP (ORCPT ); Wed, 9 Oct 2013 14:17:15 -0400 Date: Wed, 9 Oct 2013 20:16:13 +0200 From: Jakub Jelinek To: Peter Zijlstra Cc: Oleg Nesterov , Fengguang Wu , Linus Torvalds , Ingo Molnar , Linux Kernel Mailing List , Richard Henderson Subject: Re: [x86] BUG: unable to handle kernel paging request at 00740060 Message-ID: <20131009181613.GW30970@tucnak.zalov.cz> Reply-To: Jakub Jelinek References: <20131005234430.GA22485@localhost> <20131008143400.GA14721@redhat.com> <20131009080459.GA2298@localhost> <20131009124310.GA11769@redhat.com> <20131009140734.GH3081@twins.programming.kicks-ass.net> <20131009143359.GU26785@twins.programming.kicks-ass.net> <20131009144656.GV26785@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131009144656.GV26785@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1166 Lines: 27 On Wed, Oct 09, 2013 at 04:46:56PM +0200, Peter Zijlstra wrote: > On Wed, Oct 09, 2013 at 04:33:59PM +0200, Peter Zijlstra wrote: > > On Wed, Oct 09, 2013 at 04:07:34PM +0200, Peter Zijlstra wrote: > > > Once I force a x86_64 build using the 'same' config it goes away and > > > generates 'sensible' code again (although I don't see why L9 isn't > > > merged with L2): > > > > i386-SMP also generates correct code afaict; a tad stupid but not wrong. > > > > If I remove ftrace from the .config its still broken.. > > If I also remove the likely/unlikely tracer its still broken and lots > > smaller: > > OK, its -march=winchip2 that's buggered. Confirmed as gcc bug, filed http://gcc.gnu.org/PR58670 Seems all of 4.[6-9] miscompile it. Will have a look tomorrow unless somebody beats me to it. But historically, the case where asm goto labels jump to fallthru basic block had numerous problems in the past. Jakub -- 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/