Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752935AbaKVBSC (ORCPT ); Fri, 21 Nov 2014 20:18:02 -0500 Received: from www.linutronix.de ([62.245.132.108]:60138 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751847AbaKVBSA (ORCPT ); Fri, 21 Nov 2014 20:18:00 -0500 Date: Sat, 22 Nov 2014 02:17:52 +0100 (CET) From: Thomas Gleixner To: Konrad Rzeszutek Wilk cc: Linus Torvalds , Andy Lutomirski , Steven Rostedt , Tejun Heo , "linux-kernel@vger.kernel.org" , Arnaldo Carvalho de Melo , Peter Zijlstra , Frederic Weisbecker , Don Zickus , Dave Jones , the arch/x86 maintainers , xen-devel@lists.xenproject.org Subject: Re: frequent lockups in 3.18rc4 In-Reply-To: <20141121223309.GC19283@laptop.dumpdata.com> Message-ID: References: <20141121162742.GB15461@htj.dyndns.org> <20141121170805.GD30603@home.goodmis.org> <20141121223309.GC19283@laptop.dumpdata.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 21 Nov 2014, Konrad Rzeszutek Wilk wrote: > On Fri, Nov 21, 2014 at 08:51:43PM +0100, Thomas Gleixner wrote: > > On Fri, 21 Nov 2014, Linus Torvalds wrote: > > > Here's the simplified end result. Again, this is TOTALLY UNTESTED. I > > > compiled it and verified that the code generation looks like what I'd > > > have expected, but that's literally it. > > > > > > static noinline int vmalloc_fault(unsigned long address) > > > { > > > pgd_t *pgd_dst; > > > pgdval_t pgd_entry; > > > unsigned index = pgd_index(address); > > > > > > if (index < KERNEL_PGD_BOUNDARY) > > > return -1; > > > > > > pgd_entry = init_mm.pgd[index].pgd; > > > if (!pgd_entry) > > > return -1; > > > > > > pgd_dst = __va(PAGE_MASK & read_cr3()); > > > pgd_dst += index; > > > > > > if (pgd_dst->pgd) > > > return -1; > > > > > > ACCESS_ONCE(pgd_dst->pgd) = pgd_entry; > > > > This will break paravirt. set_pgd/set_pmd are paravirt functions. > > > > But I'm fine with breaking it, then you just need to change > > CONFIG_PARAVIRT to 'def_bool n' > > That is not very nice. Maybe not nice, but sensible. Thanks, tglx -- 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/