From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [RFC] dev->refcnt long term holder Date: Tue, 17 Nov 2009 09:58:46 -0800 Message-ID: <20091117095846.6ef8b4f6@nehalam> References: <4B019381.2010509@gmail.com> <20091116110207.08b60c81@nehalam> <4B01ADF5.8090904@gmail.com> <20091117.003019.196504832.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: eric.dumazet@gmail.com, herbert@gondor.apana.org.au, netdev@vger.kernel.org To: David Miller Return-path: Received: from mail.vyatta.com ([76.74.103.46]:38629 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752637AbZKQR6v (ORCPT ); Tue, 17 Nov 2009 12:58:51 -0500 In-Reply-To: <20091117.003019.196504832.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 17 Nov 2009 00:30:19 -0800 (PST) David Miller wrote: > I'm trying to remember why we added this asynchronous link state event > processing monster. It probably has something to do with needing a > sleepable context. What's amusing is that linkwatch has repeatably > caused RTNL deadlock issues over the years. :-) I thought it was to handle: 1) carrier on old devices would bounce, so it provides ratelimiting of state changes. Modern hardware and CPU's probably makes this a non-issue. 2) wasn't there some code path with device changes, hotplug, uevent and udev that meant that we couldn't do notifiers immediately. --