Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755300AbZF0HfR (ORCPT ); Sat, 27 Jun 2009 03:35:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751765AbZF0HfF (ORCPT ); Sat, 27 Jun 2009 03:35:05 -0400 Received: from lanfw001a.cxnet.dk ([87.72.215.196]:38286 "EHLO lanfw001a.cxnet.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751729AbZF0HfE (ORCPT ); Sat, 27 Jun 2009 03:35:04 -0400 Subject: Re: [PATCH 07/10] decnet: Use rcu_barrier() on module unload. From: Jesper Dangaard Brouer To: Christian Kujau Cc: Jesper Dangaard Brouer , David Miller , paulmck@linux.vnet.ibm.com, netdev , LKML , Patrick McHardy , yoshfuji@linux-ipv6.org, linux-nfs@vger.kernel.org, linux-ext4@vger.kernel.org, catalin.marinas@gmail.com In-Reply-To: References: <1245845367.24921.3.camel@localhost.localdomain> <5A680E0A-EFEB-44EA-9F06-F338E6CBD6D1@googlemail.com> <1245930729.24921.67.camel@localhost.localdomain> <20090625.161046.19938291.davem@davemloft.net> Content-Type: text/plain Organization: ComX Networks A/S Date: Sat, 27 Jun 2009 09:35:04 +0200 Message-Id: <1246088104.29340.5.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 27 Jun 2009 07:35:05.0403 (UTC) FILETIME=[CA0ED8B0:01C9F6F9] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1701 Lines: 48 On Fri, 2009-06-26 at 20:15 -0700, Christian Kujau wrote: > On Fri, 26 Jun 2009, Jesper Dangaard Brouer wrote: > > I'll resubmit the patches to you and netdev, to limit the spam effect... > > Out of curiosity: why was linux-ext4 Cc'ed on these rcu_barrier patches > (but not other fs-lists but linux-nfs)? I did not see any ../fs/ext4/ > changes. There was a ../fs/ext4/ change in patch [01/10]. Titled: "ext4: Use rcu_barrier() on module unload" git show --stat d6a4ea73b7e8779607dd48735d9a9c521c890857 commit d6a4ea73b7e8779607dd48735d9a9c521c890857 Author: Jesper Dangaard Brouer Date: Tue Jun 23 15:40:54 2009 +0200 ext4: Use rcu_barrier() on module unload. The ext4 module uses rcu_call() thus it should use rcu_barrier()on module unload. The kmem cache ext4_pspace_cachep is sometimes free'ed using call_rcu() callbacks. Thus, we must wait for completion of call_rcu() before doing kmem_cache_destroy(). I have difficult determining if no new call_rcu() callbacks can be envoked. Would the maintainer please verify this? Signed-off-by: Jesper Dangaard Brouer fs/ext4/mballoc.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) -- Med venlig hilsen / Best regards Jesper Brouer ComX Networks A/S Linux Network developer Cand. Scient Datalog / MSc. Author of http://adsl-optimizer.dk LinkedIn: http://www.linkedin.com/in/brouer -- 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/