Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758827AbZKKTxV (ORCPT ); Wed, 11 Nov 2009 14:53:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758793AbZKKTxU (ORCPT ); Wed, 11 Nov 2009 14:53:20 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:34106 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758593AbZKKTxT (ORCPT ); Wed, 11 Nov 2009 14:53:19 -0500 Date: Wed, 11 Nov 2009 11:52:04 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: "Rafael J. Wysocki" cc: Thomas Gleixner , Mike Galbraith , Ingo Molnar , LKML , pm list , Greg KH , Jesse Barnes , Tejun Heo , Oleg Nesterov , Marcel Holtmann , linux-bluetooth@vger.kernel.org Subject: Re: GPF in run_workqueue()/list_del_init(cwq->worklist.next) on resume (was: Re: Help needed: Resume problems in 2.6.32-rc, perhaps related to preempt_count leakage in keventd) In-Reply-To: <200911111252.48214.rjw@sisk.pl> Message-ID: References: <200911091250.31626.rjw@sisk.pl> <200911100119.38019.rjw@sisk.pl> <200911111252.48214.rjw@sisk.pl> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) 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: 2362 Lines: 55 On Wed, 11 Nov 2009, Rafael J. Wysocki wrote: > > I thought that the problem was somehow related to user space, because it only > happens after we've thawed tasks. At least, all of the call traces I was able > to collect indicated so. > > Moreover, in a few cases I got > > kernel: PM: Finishing wakeup. > kernel: Restarting tasks ... > kernel: usb 5-2: USB disconnect, address 2 > kernel: done. > bluetoothd[3445]: HCI dev 0 unregistered > bluetoothd[3445]: Unregister path: /org/bluez/3445/hci0 > bluetoothd[3445]: Unregistered interface org.bluez.NetworkPeer on path /org/bluez/3445/hci0 > bluetoothd[3445]: Unregistered interface org.bluez.NetworkHub on path /org/bluez/3445/hci0 > bluetoothd[3445]: Unregistered interface org.bluez.NetworkRouter on path /org/bluez/3445/hci0 > kernel: Slab corruption: size-512 start=ffff88007f1182b0, len=512 > > and so on (of course, the bluetoothd PID was different each time), so I thought > that the problem might be related to Bluetooth. Hmm. Sounds reasonable. It's still that 'size-512', but if the sound subsystem and the bluetooth code both happen to use that size, that would explain why there was sound data in the slab. > So, I've disabled the Bluetooth subsystem in the kernel config and I'm not able > to reproduce the problem any more (at least not within 50 consecutive > suspend-resume and hibernate-resume cycles). Thus Bluetooth seems to be > at least necessary to reproduce the issue and perhaps it's also the cause of > it. Which BT driver are you using? Maybe it's specific to the low-level driver? For example, I could imagine that (say) a USB bluetooth dongle (I think they are common for for mice, and are sometimes built-in on the motherboard) could get the USB "disconnect" event, and get freed while some work from the resume is still pending. I'm looking at btusb_disconnect(), for example. It's one of the few BT drivers that seem to use workqueues, and I'm not seeing a cancel_work_sync() in the disconnect routine - but maybe the btusb_close() routine is called indirectly some way that I just don't see. Marcel? Linus -- 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/