Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757888AbZFOXig (ORCPT ); Mon, 15 Jun 2009 19:38:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752050AbZFOXi1 (ORCPT ); Mon, 15 Jun 2009 19:38:27 -0400 Received: from x35.xmailserver.org ([64.71.152.41]:35546 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751501AbZFOXi0 (ORCPT ); Mon, 15 Jun 2009 19:38:26 -0400 X-AuthUser: davidel@xmailserver.org Date: Mon, 15 Jun 2009 16:32:20 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@makko.or.mcafeemobile.com To: Stefan Richter cc: Linux Kernel Mailing List Subject: Re: 2.6.30-rc1 regression? -- epoll: BUG: sleeping function called from invalid context In-Reply-To: Message-ID: References: User-Agent: Alpine 1.10 (DEB 962 2008-03-14) X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2665 Lines: 61 On Tue, 16 Jun 2009, Stefan Richter wrote: > Looks like a regression after 2.6.29, before 2.6.30-rc1, caused by > commit 5071f97ec6d74f006072de0ce89b67c8792fe5a1, "epoll: fix epoll's own > poll" (since this introduced ep_scan_ready_list), but I haven't fully > investigated yet whether this is really the cause. > > Test case: Run any libraw1394 or libdc1394 based program on > firewire-core on a kernel with the usual selection of debugging options > configured in. I didn't have these options enabled for a while, hence > noticed only now. > > BUG: sleeping function called from invalid context at kernel/mutex.c:278 > in_atomic(): 1, irqs_disabled(): 0, pid: 8301, name: dvgrab > no locks held by dvgrab/8301. > Pid: 8301, comm: dvgrab Tainted: G W 2.6.30 #2 > Call Trace: > [] ? __debug_show_held_locks+0x22/0x24 > [] __might_sleep+0x120/0x122 > [] mutex_lock_nested+0x25/0x2eb > [] ? __lock_acquire+0x705/0x793 > [] ep_scan_ready_list+0x3c/0x185 > [] ? ep_read_events_proc+0x0/0x6c > [] ep_poll_readyevents_proc+0x12/0x14 > [] ep_call_nested+0x9f/0xfa > [] ? ep_poll_readyevents_proc+0x0/0x14 > [] ep_eventpoll_poll+0x4d/0x5b > [] do_sys_poll+0x1b4/0x3b5 > [] ? __pollwait+0x0/0xce > [] ? pollwake+0x0/0x52 > [] ? mark_held_locks+0x4d/0x6a > [] ? restore_args+0x0/0x30 > [] ? trace_hardirqs_on_caller+0x10b/0x12f > [] ? mark_held_locks+0x4d/0x6a > [] ? restore_args+0x0/0x30 > [] ? __lock_acquire+0x705/0x793 > [] ? trace_hardirqs_on_caller+0x10b/0x12f > [] ? trace_hardirqs_on+0xd/0xf > [] ? timespec_add_safe+0x34/0x61 > [] ? ep_scan_ready_list+0x152/0x185 > [] ? ktime_get_ts+0x49/0x4e > [] ? poll_select_set_timeout+0x5c/0x7f > [] sys_poll+0x52/0xb2 > [] system_call_fastpath+0x16/0x1b > > Any idea how to approach this? That's not the problem. The problem is the patch changing the cookie from "current" to the current CPU (hence bumping preempt count with get_cpu()). Need a fix. Working on it ... - Davide -- 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/