From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757421Ab3DXCs6 (ORCPT ); Tue, 23 Apr 2013 22:48:58 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:47559 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756223Ab3DXCs4 (ORCPT ); Tue, 23 Apr 2013 22:48:56 -0400 Date: Tue, 23 Apr 2013 19:48:49 -0700 From: "Paul E. McKenney" To: Sedat Dilek Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, Mathieu Desnoyers , Davidlohr Bueso , Rik van Riel , Linus Torvalds Subject: Re: [PATCH tip/core/rcu 0/4] RCU debug-objects improvements Message-ID: <20130424024849.GE3427@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13042402-5518-0000-0000-00000DDE5B37 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 24, 2013 at 03:45:20AM +0200, Sedat Dilek wrote: > [ QUOTE ] > > Hello! > > RCU's current debug-objects fixups are complex and heavyweight, plus the > fixups are not complete, because even with the fixups, RCU's callback > lists can still be corrupted. This series reworks RCU's use of the > debug-objects facility and the facility itself to allow improved handling > of things like duplicate invocations of call_rcu(). This series includes: > > 1. Simplify RCU's debug-objects fixups. > > 2. Make debug_object_activate() return status. > > 3. Make __call_rcu() leak callbacks when debug_object_activate() > notes suspicious activity. Leaking has its problems, but it > is far better than silent corruption of RCU's data structures. > > 4. Add a new object_debug option to rcutorture to allow > deterministic testing of #3 above. > > Thanx, Paul > > > b/include/linux/debugobjects.h | 6 +- > b/kernel/rcu.h | 10 ++-- > b/kernel/rcupdate.c | 100 ----------------------------------------- > b/kernel/rcutorture.c | 37 +++++++++++++++ > b/kernel/rcutree.c | 14 +++++ > b/lib/debugobjects.c | 20 +++++--- > 6 files changed, 74 insertions(+), 113 deletions(-) > > [ /QUOTE ] > > I applied your patchset against the "buggy" Linux-Next (next-20130423) > with none of the ipc-sem-next patches (even w/o the suggested Linus > patch) to see if I see more debug-outputs, > > I have attached my syslog while building my kernel. > Please, have a look! The warnings and the leaking of the offending callback are all present, thank you for testing this! > Thanks for the patches. > > Feel free to add to all of the 4 patches my Tested-by. Will do! Thanx, Paul > - Sedat - > > [1] http://marc.info/?l=linux-kernel&m=136676361101735&w=2