Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756295AbZKIP60 (ORCPT ); Mon, 9 Nov 2009 10:58:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756065AbZKIP6Z (ORCPT ); Mon, 9 Nov 2009 10:58:25 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:45260 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756078AbZKIP6Z (ORCPT ); Mon, 9 Nov 2009 10:58:25 -0500 Date: Mon, 9 Nov 2009 07:57:35 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Thomas Gleixner cc: Ingo Molnar , "Rafael J. Wysocki" , LKML , pm list , Greg KH , Jesse Barnes Subject: Re: Help needed: Resume problems in 2.6.32-rc, perhaps related to preempt_count leakage in keventd In-Reply-To: Message-ID: References: <200911091250.31626.rjw@sisk.pl> <20091109120217.GB18399@elte.hu> <200911091324.37955.rjw@sisk.pl> <20091109124937.GA21114@elte.hu> 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: 1206 Lines: 29 On Mon, 9 Nov 2009, Thomas Gleixner wrote: > > I think it _IS_ releated because the worker_thread is CPU affine and > the debug_smp_processor_id() check does: Hmm. We do know CPU affinity is destroyed by CPU hotplug. People have complained about that before (for user-space processes that get moved around due to hot-unplug/plug). And the suspend/resume process does CPU hotplug to take down all but one CPU. The workqueues should act on those events already, but maybe there's a bug somewhere. None of that is new to 32-rc, though - is it? And workqueue_cpu_callback() seems buggy. It loops over the 'workqueues' list with no protection. Yes, we do 'stop_machine' for CPU hotplug events, but only for the very internal one (CPU_DYING) will the CPU notifiers be called with the machine stopped). Hmm. I don't see any changes in kernel/cpu.c or kernel/workqueue.c that look at all relevant. But scheduler changes could certainly matter. 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/