Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965647AbXAXEa1 (ORCPT ); Tue, 23 Jan 2007 23:30:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965651AbXAXEa1 (ORCPT ); Tue, 23 Jan 2007 23:30:27 -0500 Received: from smtp.osdl.org ([65.172.181.24]:50836 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965647AbXAXEa0 (ORCPT ); Tue, 23 Jan 2007 23:30:26 -0500 Date: Tue, 23 Jan 2007 20:29:09 -0800 From: Andrew Morton To: Mathieu Desnoyers Cc: Ingo Molnar , Greg Kroah-Hartman , Christoph Hellwig , linux-kernel@vger.kernel.org, ltt-dev@shafik.org, "Martin J. Bligh" , Douglas Niehaus , systemtap@sources.redhat.com, Thomas Gleixner , Richard J Moore Subject: Re: [PATCH 2/2] lockdep reentrancy Message-Id: <20070123202909.6b7dcd17.akpm@osdl.org> In-Reply-To: <20070116175631.GB16084@Krystal> References: <20061220235216.GA28643@Krystal> <20070116175631.GB16084@Krystal> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2821 Lines: 108 On Tue, 16 Jan 2007 12:56:31 -0500 Mathieu Desnoyers wrote: > Here is a patch to lockdep.c so it behaves correctly when a kprobe breakpoint is > put on a marker within hardirq tracing functions as long as the marker is within > the lockdep_recursion incremented boundaries. It should apply on > 2.6.20-rc4-git3. > > Mathieu > > Signed-off-by: Mathieu Desnoyers > > > @@ -1841,33 +1843,36 @@ void trace_hardirqs_on(void) You lost the patch headers. > struct task_struct *curr = current; > unsigned long ip; > > if (unlikely(!debug_locks || current->lockdep_recursion)) > return; > > + current->lockdep_recursion++; > + barrier(); Why can't we use lockdep_off() here? > if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled))) > - return; > + goto end; > > if (unlikely(curr->hardirqs_enabled)) { > debug_atomic_inc(&redundant_hardirqs_on); > - return; > + goto end; > } > /* we'll do an OFF -> ON transition: */ > curr->hardirqs_enabled = 1; > ip = (unsigned long) __builtin_return_address(0); > > if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) > - return; > + goto end; > if (DEBUG_LOCKS_WARN_ON(current->hardirq_context)) > - return; > + goto end; > /* > * We are going to turn hardirqs on, so set the > * usage bit for all held locks: > */ > if (!mark_held_locks(curr, 1, ip)) > - return; > + goto end; > /* > * If we have softirqs enabled, then set the usage > * bit for all held locks. (disabled hardirqs prevented > @@ -1875,11 +1880,14 @@ void trace_hardirqs_on(void) > */ > if (curr->softirqs_enabled) > if (!mark_held_locks(curr, 0, ip)) > - return; > + goto end; > > curr->hardirq_enable_ip = ip; > curr->hardirq_enable_event = ++curr->irq_events; > debug_atomic_inc(&hardirqs_on_events); > +end: > + barrier(); > + current->lockdep_recursion--; lockdep_on()? > } > > EXPORT_SYMBOL(trace_hardirqs_on); > @@ -1888,14 +1896,17 @@ void trace_hardirqs_off(void) > { > struct task_struct *curr = current; > > if (unlikely(!debug_locks || current->lockdep_recursion)) > return; > > + current->lockdep_recursion++; > + barrier(); lockdep_off()? > if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) > - return; > + goto end; > > if (curr->hardirqs_enabled) { > /* > @@ -1910,6 +1921,9 @@ void trace_hardirqs_off(void) > debug_atomic_inc(&hardirqs_off_events); > } else > debug_atomic_inc(&redundant_hardirqs_off); > +end: > + barrier(); > + current->lockdep_recursion--; lockdep_on()? - 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/