Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758461AbXEWXfU (ORCPT ); Wed, 23 May 2007 19:35:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756343AbXEWXfJ (ORCPT ); Wed, 23 May 2007 19:35:09 -0400 Received: from sd-green-bigip-202.dreamhost.com ([208.97.132.202]:39637 "EHLO spaceymail-a2.g.dreamhost.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756310AbXEWXfH (ORCPT ); Wed, 23 May 2007 19:35:07 -0400 From: Anant Nitya Organization: Prachanda Hub To: linux-kernel@vger.kernel.org Subject: Re: [BUG] local_softirq_pending storm Date: Thu, 24 May 2007 04:54:29 +0530 User-Agent: KMail/1.9.6 Cc: Chuck Ebbert , Ingo Molnar , Michal Piotrowski , Thomas Gleixner , David Miller , Netdev References: <200705091942.22920.kernel@prachanda.hub> <46547345.8000808@redhat.com> <46548A30.9000801@redhat.com> In-Reply-To: <46548A30.9000801@redhat.com> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200705240454.30353.kernel@prachanda.hub> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4803 Lines: 98 On Thursday 24 May 2007 00:08:40 Chuck Ebbert wrote: > Chuck Ebbert wrote: > > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=240982 > > Another; these started to appear after the below patch was merged: > > Index: linux/kernel/sched.c > > > > > =================================================================== > > > --- linux.orig/kernel/sched.c > > > +++ linux/kernel/sched.c > > > @@ -4212,9 +4212,7 @@ int __sched cond_resched_softirq(void) > > > BUG_ON(!in_softirq()); > > > > > > if (need_resched() && system_state == SYSTEM_RUNNING) { > > > - raw_local_irq_disable(); > > > - _local_bh_enable(); > > > - raw_local_irq_enable(); > > > + local_bh_enable(); > > > __cond_resched(); > > > local_bh_disable(); > > > return 1; > > May 23 19:26:26 localhost kernel: BUG: warning at > kernel/softirq.c:138/local_bh_enable() (Not tainted) May 23 19:26:26 > localhost kernel: [] local_bh_enable+0x45/0x92 May 23 19:26:26 > localhost kernel: [] cond_resched_softirq+0x2c/0x42 May 23 > 19:26:26 localhost kernel: [] release_sock+0x54/0xa3 May 23 > 19:26:26 localhost kernel: [] prepare_to_wait+0x24/0x3f May 23 > 19:26:26 localhost kernel: [] inet_stream_connect+0x116/0x1ff > May 23 19:26:26 localhost kernel: [] > autoremove_wake_function+0x0/0x35 May 23 19:26:26 localhost kernel: > [] sys_connect+0x82/0xad May 23 19:26:26 localhost kernel: > [] release_sock+0x13/0xa3 May 23 19:26:26 localhost kernel: > [] _spin_unlock_bh+0x5/0xd May 23 19:26:26 localhost kernel: > [] sock_setsockopt+0x4a8/0x4b2 May 23 19:26:26 localhost kernel: > [] sock_attach_fd+0x70/0xd2 May 23 19:26:26 localhost kernel: > [] get_empty_filp+0xfc/0x170 May 23 19:26:26 localhost kernel: > [] sys_setsockopt+0x9b/0xa7 May 23 19:26:26 localhost kernel: > [] sys_socketcall+0xac/0x261 May 23 19:26:26 localhost kernel: > [] syscall_call+0x7/0xb strange, while applying the concerned patch first time I was hand editing __ kernel/sched.c __ and stupidly typed _local_bh_enable() instead of local_bh_enable() and when did a reboot, as soon as I got inside X I was welcomed with following message in system log. [ 152.692609] BUG: at kernel/softirq.c:122 _local_bh_enable() [ 152.692637] [] show_trace_log_lvl+0x1a/0x2f [ 152.692658] [] show_trace+0x12/0x14 [ 152.692668] [] dump_stack+0x16/0x18 [ 152.692678] [] _local_bh_enable+0x8b/0xc3 [ 152.692688] [] cond_resched_softirq+0x2b/0x40 [ 152.692700] [] established_get_first+0x19/0xad [ 152.692712] [] tcp_seq_next+0x76/0x8c [ 152.692722] [] seq_read+0x17b/0x264 [ 152.692733] [] vfs_read+0xad/0x161 [ 152.692745] [] sys_read+0x3d/0x61 [ 152.692755] [] syscall_call+0x7/0xb [ 152.692765] ======================= [ 152.692770] BUG: at kernel/lockdep.c:1937 trace_softirqs_on() [ 152.692777] [] show_trace_log_lvl+0x1a/0x2f [ 152.692789] [] show_trace+0x12/0x14 [ 152.692800] [] dump_stack+0x16/0x18 [ 152.692810] [] trace_softirqs_on+0x5f/0xa5 [ 152.692822] [] _local_bh_enable+0xb3/0xc3 [ 152.692831] [] cond_resched_softirq+0x2b/0x40 [ 152.692842] [] established_get_first+0x19/0xad [ 152.692852] [] tcp_seq_next+0x76/0x8c [ 152.692862] [] seq_read+0x17b/0x264 [ 152.692870] [] vfs_read+0xad/0x161 [ 152.692879] [] sys_read+0x3d/0x61 [ 152.692889] [] syscall_call+0x7/0xb [ 152.692899] ======================= [ 159.257890] NOHZ: local_softirq_pending 22 [ 159.266009] NOHZ: local_softirq_pending 22 [ 159.273965] NOHZ: local_softirq_pending 22 [ 159.281884] NOHZ: local_softirq_pending 22 [ 160.712828] NOHZ: local_softirq_pending 22 [ 162.609377] NOHZ: local_softirq_pending 22 [ 162.609804] NOHZ: local_softirq_pending 22 [ 162.610054] NOHZ: local_softirq_pending 22 [ 162.610279] NOHZ: local_softirq_pending 22 [ 162.610502] NOHZ: local_softirq_pending 22 After realzing my mistake, I changed it to local_bh_enable() as was in patch and since then not a single BUG or local_softirq_pending message occurs in system log, maybe my system waiting for that condition to happen :). -- Out of many thousands, one may endeavor for perfection, and of those who have achieved perfection, hardly one knows Me in truth. -- Gita Sutra Of Mysticism - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/