Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758639AbYHDQjY (ORCPT ); Mon, 4 Aug 2008 12:39:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754339AbYHDQjP (ORCPT ); Mon, 4 Aug 2008 12:39:15 -0400 Received: from viefep18-int.chello.at ([213.46.255.22]:14944 "EHLO viefep18-int.chello.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753803AbYHDQjO (ORCPT ); Mon, 4 Aug 2008 12:39:14 -0400 X-SourceIP: 80.57.229.25 Subject: Re: [RFC][PATCH 7/7] lockdep: spin_lock_nest_lock() From: Peter Zijlstra To: Andrea Arcangeli Cc: Dave Jones , Roland Dreier , Linus Torvalds , David Miller , jeremy@goop.org, hugh@veritas.com, mingo@elte.hu, akpm@linux-foundation.org, linux-kernel@vger.kernel.org In-Reply-To: <20080804162657.GI11476@duo.random> References: <20080804130317.994042639@chello.nl> <20080804131012.246115111@chello.nl> <1217859571.3589.7.camel@twins> <1217860332.3589.11.camel@twins> <20080804145318.GA17867@redhat.com> <1217861763.3589.13.camel@twins> <20080804162657.GI11476@duo.random> Content-Type: text/plain Date: Mon, 04 Aug 2008 18:38:55 +0200 Message-Id: <1217867935.3589.35.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2211 Lines: 64 On Mon, 2008-08-04 at 18:26 +0200, Andrea Arcangeli wrote: > On Mon, Aug 04, 2008 at 04:56:03PM +0200, Peter Zijlstra wrote: > > My guess is that the kvm thing attaches before there are any vma, and > > leaves after all the vma are gone. So it would never actually trigger. > > Yes, lockdep seems to be fine with kvm in kernel mainline in my > current and past testing. Andrew asked me to check this long ago. > > vmx ~ # zgrep LOCKDEP /proc/config.gz > CONFIG_LOCKDEP_SUPPORT=y > CONFIG_LOCKDEP=y > CONFIG_DEBUG_LOCKDEP=y You also need CONFIG_PROVE_LOCKING, but I'll assume that's set too. > CPA self-test: > 4k 26112 large 1997 gb 0 x 2652[ffff880000000000-ffff8800bffff000] > miss 262144 > 4k 186880 large 1683 gb 0 x 43021[ffff880000000000-ffff8800bffff000] > miss 262144 > 4k 186880 large 1683 gb 0 x 43021[ffff880000000000-ffff8800bffff000] > miss 262144 > ok. > loaded kvm module () > apic write: bad size=1 fee00030 > Ignoring de-assert INIT to vcpu 0 > Ignoring de-assert INIT to vcpu 0 > kvm: emulating exchange as write > apic write: bad size=1 fee00030 > Ignoring de-assert INIT to vcpu 0 > Ignoring de-assert INIT to vcpu 0 > apic write: bad size=1 fee00030 > Ignoring de-assert INIT to vcpu 0 > Ignoring de-assert INIT to vcpu 0 > apic write: bad size=1 fee00030 > Ignoring de-assert INIT to vcpu 0 > apic write: bad size=1 fee00030 > Ignoring de-assert INIT to vcpu 0 > apic write: bad size=1 fee00030 > Ignoring de-assert INIT to vcpu 0 > Ignoring de-assert INIT to vcpu 0 > Ignoring de-assert INIT to vcpu 0 > > I can't see lockdep errors in dmesg starting one more multiple VM in a > loop (all run on a quadcore). Dave Jones just handed me: https://bugzilla.redhat.com/show_bug.cgi?id=457779 > GRU is likely the same. > > The only real place where lockdep is unusable in my experience is > preempt-RT, it grinds it to an halt during boot on 8-way before > reaching the shell. David Miller just did a patch that might fix that. -- 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/