From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759275AbYFTP2W (ORCPT ); Fri, 20 Jun 2008 11:28:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756249AbYFTP2K (ORCPT ); Fri, 20 Jun 2008 11:28:10 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:56528 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756034AbYFTP2J (ORCPT ); Fri, 20 Jun 2008 11:28:09 -0400 Date: Fri, 20 Jun 2008 17:27:48 +0200 From: Ingo Molnar To: Johannes Berg Cc: Linus Torvalds , Linux Kernel list , Michael Buesch , David Ellingsworth , linux-wireless Subject: Re: [PATCH/RFC] remove irqs_disabled warning from local_bh_enable Message-ID: <20080620152748.GA21245@elte.hu> References: <1213739834.3803.137.camel@johannes.berg> <1213774177.3803.164.camel@johannes.berg> <20080620134637.GA8135@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080620134637.GA8135@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > > Subject: clean up and comment local_bh_enable code > > > > There's no need to use local_irq_save() over local_irq_disable() in > > the local_bh_enable code since it is a bug to call it with irqs > > disabled and do_softirq will enable irqs if there is any pending > > work. Consolidate the code from local_bh_enable and ..._ip to avoid > > having a disconnect between them in the warnings they trigger that > > is currently there. Also always trigger the warning on in_irq(), not > > just in the trace-irqflags case. > > applied to tip/core/softirq for testing, thanks Johannes. ok, -tip testing found that your patch triggers a new warning on an old testbox that uses 3c59x vortex and netlogging: -----> calling vortex_init+0x0/0xb0 PCI: Found IRQ 10 for device 0000:00:0b.0 PCI: Sharing IRQ 10 with 0000:00:0a.0 PCI: Sharing IRQ 10 with 0000:00:0b.1 3c59x: Donald Becker and others. 0000:00:0b.0: 3Com PCI 3c556 Laptop Tornado at e0800400. PCI: Enabling bus mastering for device 0000:00:0b.0 initcall vortex_init+0x0/0xb0 returned 0 after 47 msecs ... calling init_netconsole+0x0/0x1b0 netconsole: local port 4444 netconsole: local IP 10.0.1.9 netconsole: interface eth0 netconsole: remote port 4444 netconsole: remote IP 10.0.1.16 netconsole: remote ethernet address 00:19:xx:xx:xx:xx netconsole: device eth0 not up yet, forcing it eth0: setting half-duplex. eth0: setting full-duplex. ------------[ cut here ]------------ WARNING: at kernel/softirq.c:137 local_bh_enable_ip+0xd1/0xe0() Pid: 1, comm: swapper Not tainted 2.6.26-rc6-tip #2091 [] warn_on_slowpath+0x4f/0x70 [] ? release_console_sem+0x1b4/0x1d0 [] ? vprintk+0x2a0/0x450 [] ? __mod_timer+0xa5/0xc0 [] ? mdio_sync+0x3d/0x50 [] ? marker_probe_cb+0x46/0xa0 [] ? printk+0x27/0x50 [] ? vortex_set_duplex+0x43/0xc0 [] ? vortex_set_duplex+0xa1/0xc0 [] ? vortex_timer+0xe2/0x3e0 [] local_bh_enable_ip+0xd1/0xe0 [] _spin_unlock_bh+0x2f/0x40 [] vortex_timer+0xe2/0x3e0 [] ? trace_hardirqs_on+0xb/0x10 [] ? trace_hardirqs_on_caller+0x88/0x160 [] run_timer_softirq+0x162/0x1c0 [] ? vortex_timer+0x0/0x3e0 [] local_bh_enable_ip+0xd1/0xe0 [] _spin_unlock_bh+0x2f/0x40 [] vortex_timer+0xe2/0x3e0 [] ? trace_hardirqs_on+0xb/0x10 [] ? trace_hardirqs_on_caller+0x88/0x160 [] run_timer_softirq+0x162/0x1c0 [] ? vortex_timer+0x0/0x3e0 [] ? vortex_timer+0x0/0x3e0 [] __do_softirq+0x9a/0x160 [] ? __do_softirq+0x0/0x160 [] call_on_stack+0x15/0x30 [] ? irq_exit+0x55/0x60 [] ? do_IRQ+0x85/0xd0 [] ? trace_hardirqs_on_caller+0xc1/0x160 [] ? common_interrupt+0x28/0x30 [] ? mutex_unlock+0x8/0x10 [] ? _cond_resched+0x10/0x30 [] ? netpoll_setup+0x117/0x390 [] ? init_netconsole+0x14e/0x1b0 [] ? ktime_get+0x19/0x40 [] ? kernel_init+0x1b2/0x2c0 [] ? init_netconsole+0x0/0x1b0 [] ? trace_hardirqs_on_thunk+0xc/0x10 [] ? restore_nocheck_notrace+0x0/0xe [] ? kernel_init+0x0/0x2c0 [] ? kernel_init+0x0/0x2c0 [] ? kernel_thread_helper+0x7/0x10 ======================= ---[ end trace 37f9c502aff112e0 ]--- console [netcon0] enabled netconsole: network logging started initcall init_netconsole+0x0/0x1b0 returned 0 after 2914 msecs real bug or false positive? config is at: http://redhat.com/~mingo/misc/config-Fri_Jun_20_16_51_07_CEST_2008.bad Ingo