Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755642AbYHDQ1S (ORCPT ); Mon, 4 Aug 2008 12:27:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753238AbYHDQ1G (ORCPT ); Mon, 4 Aug 2008 12:27:06 -0400 Received: from host36-195-149-62.serverdedicati.aruba.it ([62.149.195.36]:47386 "EHLO mx.cpushare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751852AbYHDQ1F (ORCPT ); Mon, 4 Aug 2008 12:27:05 -0400 Date: Mon, 4 Aug 2008 18:26:57 +0200 From: Andrea Arcangeli To: Peter Zijlstra 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 Subject: Re: [RFC][PATCH 7/7] lockdep: spin_lock_nest_lock() Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1217861763.3589.13.camel@twins> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1855 Lines: 53 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 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). 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. -- 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/