From: "Paul E. McKenney" Subject: Re: [PATCH 1/5] 8021q: Vlan driver should use rcu_barrier() on unload instead of syncronize_net() Date: Mon, 8 Jun 2009 08:54:46 -0700 Message-ID: <20090608155446.GB6961@linux.vnet.ibm.com> References: <20090608130959.10052.54590.stgit@localhost> <20090608131128.10052.30759.stgit@localhost> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, urs.thuermann@volkswagen.de, oliver.hartkopp@volkswagen.de, wg@grandegger.com, vladislav.yasevich@hp.com, sri@us.ibm.com, linux-sctp@vger.kernel.org, Trond.Myklebust@netapp.com, linux-nfs@vger.kernel.org, netfilter-devel@vger.kernel.org To: Jesper Dangaard Brouer Return-path: In-Reply-To: <20090608131128.10052.30759.stgit@localhost> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Jun 08, 2009 at 03:11:28PM +0200, Jesper Dangaard Brouer wrote: > The VLAN 8021q driver needs to call rcu_barrier() when unloading the module, > instead of syncronize_net(). This is needed to make sure that outstanding > call_rcu() callbacks have completed, before the callback function code is > removed on module unload. Looks good! And thank you for checking up on this!!! Reviewed-by: Paul E. McKenney > Signed-off-by: Jesper Dangaard Brouer > --- > > net/8021q/vlan.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c > index 714e1c3..fe64908 100644 > --- a/net/8021q/vlan.c > +++ b/net/8021q/vlan.c > @@ -758,7 +758,7 @@ static void __exit vlan_cleanup_module(void) > BUG_ON(!hlist_empty(&vlan_group_hash[i])); > > unregister_pernet_gen_device(vlan_net_id, &vlan_net_ops); > - synchronize_net(); > + rcu_barrier(); /* Wait for completion of call_rcu()'s */ > > vlan_gvrp_uninit(); > } >