From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754440AbaJUHEc (ORCPT ); Tue, 21 Oct 2014 03:04:32 -0400 Received: from e06smtp16.uk.ibm.com ([195.75.94.112]:48691 "EHLO e06smtp16.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753162AbaJUHEb (ORCPT ); Tue, 21 Oct 2014 03:04:31 -0400 Date: Tue, 21 Oct 2014 09:04:24 +0200 From: Heiko Carstens To: Thomas Graf Cc: Eric Dumazet , Sasha Levin , paulmck@linux.vnet.ibm.com, Nikolay Aleksandrov , "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Ursula Braun Subject: Re: [PATCH] netlink: Re-add locking to netlink_lookup() and seq walker Message-ID: <20141021070424.GA4161@osiris> References: <20141011083627.GB5074@osiris> <1413055964.9362.50.camel@edumazet-glaptop2.roam.corp.google.com> <20141011222514.GA14186@casper.infradead.org> <20141020082107.GB4268@osiris> <20141020195355.GA2299@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141020195355.GA2299@casper.infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14102107-0025-0000-0000-000001FB648A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 20, 2014 at 08:53:55PM +0100, Thomas Graf wrote: > Heiko, > > Can you test the following patch: > > 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. > > Signed-off-by: Thomas Graf > --- > net/netlink/af_netlink.c | 37 +++++++++++++++++++++++++------------ > 1 file changed, 25 insertions(+), 12 deletions(-) Thanks a lot! Your patch fixes the issue for me. Reported-and-tested-by: Heiko Carstens