From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Mackall Subject: Re: [PATCH] Prevent netpoll hanging when link is down Date: Fri, 8 Oct 2004 16:53:03 -0500 Sender: netdev-bounce@oss.sgi.com Message-ID: <20041008215303.GD31237@waste.org> References: <20041006234912.66bfbdcc.davem@davemloft.net> <20041007160532.60c3f26b@pirandello> <20041007112846.5c85b2d9.davem@davemloft.net> <20041007224422.1c1bea95@jack.colino.net> <20041007214505.GB31558@wotan.suse.de> <20041007215025.GT31237@waste.org> <20041007150756.2373719f.davem@davemloft.net> <20041007234322.GW31237@waste.org> <20041007235022.GB19864@wotan.suse.de> <20041008084640.58976145@pirandello> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andi Kleen , "David S. Miller" , akpm@osdl.org, netdev@oss.sgi.com Return-path: To: Colin Leroy Content-Disposition: inline In-Reply-To: <20041008084640.58976145@pirandello> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Fri, Oct 08, 2004 at 08:46:40AM +0200, Colin Leroy wrote: > On 08 Oct 2004 at 01h10, Andi Kleen wrote: > > Hi, > > > > Deadlocks from recursion, presumably? We could probably throw in a > > > max retry count, as ugly as that is.. > > > > There should not be any recursion, no. > > If printk() is synchronous, there could be, if there's a printk() in the > codepath taken by dev->hard_start_xmit()... But I don't if it is... Have you looked at the code path that does carrier detect for possibly recursing printks? > > For most network drivers this shouldn't occur though because > > the net driver private lock is usually always taken with interrupts > > off. > > Second newbie question: how are the interrupts disabled, is it via > local_irq_save()/local_irq_restore()? or is it something else ? Often by virtue of being in an interrupt context already. -- Mathematics is the supreme nostalgia of our time.