From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755069Ab1KUN6s (ORCPT ); Mon, 21 Nov 2011 08:58:48 -0500 Received: from mail-yw0-f46.google.com ([209.85.213.46]:45081 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754759Ab1KUN6r (ORCPT ); Mon, 21 Nov 2011 08:58:47 -0500 MIME-Version: 1.0 Date: Mon, 21 Nov 2011 14:58:46 +0100 Message-ID: Subject: softirq oops from b44_poll From: Xander Hover To: peter.p.waskiewicz.jr@intel.com Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, I noticed the small discussion about the b44_poll OOPS and I also have a uni-processor PC with a broadcom network device (b44) that causes similar kernel OOPSes. Here is a (reproducible) trace that still shows up in kernel 3.1.1: ------------[ cut here ]------------ WARNING: at kernel/softirq.c:159 local_bh_enable+0x32/0x79() Hardware name: Dimension 2400 Modules linked in: snd_seq_midi snd_emu10k1_synth snd_emux_synth snd_seq_virmidi snd_seq_midi_emul snd_seq_oss snd_seq_midi_event snd_seq snd_pcm_oss snd_mixer_oss bnep rfcomm cryptd aes_i586 aes_generic ecb btusb bluetooth rfkill ppdev snd_emu10k1 snd_rawmidi snd_ac97_codec ac97_bus snd_pcm snd_seq_device snd_timer snd_page_alloc dcdbas snd_util_mem parport_pc snd_hwdep snd parport emu10k1_gp rtc_cmos gameport i2c_i801 Pid: 0, comm: swapper Not tainted 3.1.1-gentoo #1 Call Trace: [] warn_slowpath_common+0x65/0x7a [] ? local_bh_enable+0x32/0x79 [] warn_slowpath_null+0xf/0x13 [] local_bh_enable+0x32/0x79 [] destroy_conntrack+0x7c/0x9b [] nf_conntrack_destroy+0x1f/0x26 [] skb_release_head_state+0x74/0x83 [] __kfree_skb+0xb/0x6b [] consume_skb+0x24/0x26 [] b44_poll+0xaa/0x449 [] net_rx_action+0x3f/0xea [] __do_softirq+0x5f/0xd5 [] ? local_bh_enable+0x79/0x79 [] ? irq_exit+0x34/0x8d [] ? do_IRQ+0x74/0x87 [] ? common_interrupt+0x29/0x30 [] ? default_idle+0x29/0x3e [] ? cpu_idle+0x2f/0x5d [] ? rest_init+0x79/0x7b [] ? start_kernel+0x297/0x29c [] ? i386_start_kernel+0xb0/0xb7 ---[ end trace 583f33bb1aa207a9 ]--- However if I apply the following patch this error does not show up anymore: diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c index 4cf835d..3fb66d0 100644 --- a/drivers/net/ethernet/broadcom/b44.c +++ b/drivers/net/ethernet/broadcom/b44.c @@ -608,7 +608,7 @@ static void b44_tx(struct b44 *bp) skb->len, DMA_TO_DEVICE); rp->skb = NULL; - dev_kfree_skb(skb); + dev_kfree_skb_irq(skb); } bp->tx_cons = cons; -- 1.7.8.rc3 This is a "works for me..", however it may very well be that this only suppresses the symptoms instead of solving the root cause. I got this idea from a previous patch (see commit log below) which did the exact opposite from this patch. -------------- commit 4924f44b97a034dbf44c14b709b0b0907ee23f04 Author: Eric Dumazet Date: Mon Jul 4 17:57:10 2011 -0700 b44: use dev_kfree_skb() in b44_tx() b44_tx() is run from softirq handler, it can use dev_kfree_skb() instead of dev_kfree_skb_irq() -------------- Any thoughts? Kind regards, Xander Hover