From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765488AbXGSKkc (ORCPT ); Thu, 19 Jul 2007 06:40:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753101AbXGSKkX (ORCPT ); Thu, 19 Jul 2007 06:40:23 -0400 Received: from agminet01.oracle.com ([141.146.126.228]:23821 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751999AbXGSKkW (ORCPT ); Thu, 19 Jul 2007 06:40:22 -0400 From: Olaf Kirch Organization: Oracle To: Ingo Molnar Subject: Re: [patch] revert: [NET]: Fix races in net_rx_action vs netpoll Date: Thu, 19 Jul 2007 12:37:54 +0200 User-Agent: KMail/1.9.1 Cc: Jarek Poplawski , Linus Torvalds , linux-kernel@vger.kernel.org, davem@davemloft.net References: <20070716091236.GA10718@elte.hu> <200707191144.24434.olaf.kirch@oracle.com> <20070719100135.GA2986@elte.hu> In-Reply-To: <20070719100135.GA2986@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707191237.56455.olaf.kirch@oracle.com> X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 19 July 2007 12:01, Ingo Molnar wrote: > Calling initcall 0xc0603f55: netpoll_init+0x0/0x39() > initcall 0xc0603f55: netpoll_init+0x0/0x39() returned 0. > initcall 0xc0603f55 ran for 0 msecs: netpoll_init+0x0/0x39() > Calling initcall 0xc0604257: netlink_proto_init+0x0/0x12a() > NET: Registered protocol family 16 > > and no output ever since - and the box has been up for a few minutes. Okay, I need to ask a stupid question - did you verify that it's not spinning on a spinlock? Specifically, I'm wondering whether the net_rx_action softirq may be scheduled while we're in poll_napi holding the poll_lock. net_rx_action would try to take the poll_lock as well, and we'd be hung for good. The patch with local_bh_disable/enable was supposed to test that idea (this is the "trickle" patch) Olaf -- Olaf Kirch | --- o --- Nous sommes du soleil we love when we play okir@lst.de | / | \ sol.dhoop.naytheet.ah kin.ir.samse.qurax