From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754183AbaJVBgM (ORCPT ); Tue, 21 Oct 2014 21:36:12 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:54034 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751091AbaJVBgI (ORCPT ); Tue, 21 Oct 2014 21:36:08 -0400 Date: Tue, 21 Oct 2014 21:36:04 -0400 (EDT) Message-Id: <20141021.213604.498626106621926349.davem@davemloft.net> To: tgraf@suug.ch Cc: davem@davemloft.ne, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, eric.dumazet@gmail.com Subject: Re: [PATCH] netlink: Re-add locking to netlink_lookup() and seq walker From: David Miller In-Reply-To: <14101d52c64e0d52176ca0d4b8888f8cf20ab9b0.1413921873.git.tgraf@suug.ch> References: <14101d52c64e0d52176ca0d4b8888f8cf20ab9b0.1413921873.git.tgraf@suug.ch> X-Mailer: Mew version 6.6 on Emacs 24.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Tue, 21 Oct 2014 18:36:07 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Graf Date: Tue, 21 Oct 2014 22:05:38 +0200 > The synchronize_rcu() in netlink_release() introduces unacceptable > latency. Reintroduce minimal lookup so we can drop the > synchronize_rcu() until socket destruction has been RCUfied. > > Cc: David S. Miller > Cc: Eric Dumazet > Reported-by: Steinar H. Gunderson > Reported-and-tested-by: Heiko Carstens > Signed-off-by: Thomas Graf Applied and queued up for -stable. Please use an appropriate "Fixes: " tag in the future, this is especially important for an issue as serious as this one. Thanks.