From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH] net: deadlock during net device unregistration Date: Sun, 5 Oct 2008 09:12:38 +0200 Message-ID: <20081005071238.GA2752@ami.dom.local> References: <20081005065509.GA2538@ami.dom.local> <20081005065648.GA13113@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Benjamin Thery , davem@davemloft.net, netdev@vger.kernel.org, dlezcano@fr.ibm.com To: Herbert Xu Return-path: Received: from ug-out-1314.google.com ([66.249.92.173]:49783 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752529AbYJEHMh (ORCPT ); Sun, 5 Oct 2008 03:12:37 -0400 Received: by ug-out-1314.google.com with SMTP id k3so1473918ugf.37 for ; Sun, 05 Oct 2008 00:12:35 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20081005065648.GA13113@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, Oct 05, 2008 at 02:56:48PM +0800, Herbert Xu wrote: > On Sun, Oct 05, 2008 at 08:55:10AM +0200, Jarek Poplawski wrote: > > > > > - /* Not safe to do outside the semaphore. We must not return > > > - * until all unregister events invoked by the local processor > > > - * have been completed (either by this todo run, or one on > > > - * another cpu). > > > - */ > > > > I think, it's about not to let others run this for devices unregistered > > within later rtnl_locks before completing previous tasks. So, it would > > be nice to have some comment why it's not necessary anymore. > > Where did you get that idea? Just reading this code (plus the comment). Why would anybody bother with something so complex like this if something like your idea is rather straightforward? But, needed or not, my point is it would be nice to comment that this patch changes this behavior btw. Jarek P.