Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755690AbYJZReS (ORCPT ); Sun, 26 Oct 2008 13:34:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753273AbYJZReE (ORCPT ); Sun, 26 Oct 2008 13:34:04 -0400 Received: from netrider.rowland.org ([192.131.102.5]:3481 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752791AbYJZReC (ORCPT ); Sun, 26 Oct 2008 13:34:02 -0400 Date: Sun, 26 Oct 2008 13:34:00 -0400 (EDT) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: "Mikko C." cc: Kernel development list , USB list Subject: Bug in workqueues [was: Usb devices randomly aren't detected with 2.6.28-rc1-git1] In-Reply-To: <4904A77C.7090805@gmail.com> Message-ID: 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: 1603 Lines: 42 This is no longer a USB issue, so I'm asking for help from the general kernel community. Background can be found in Bugzilla #11853. On Sun, 26 Oct 2008, Mikko C. wrote: > Mikko C. ha scritto: > > Alan Stern ha scritto: > >> > >> I don't see anything in there that looks particularly suspicious. > >> The nature of your errors suggests that the default workqueue has > >> crashed or hung, but it shows up okay in the dump. Are you sure this > >> dump was made when the devices failed to appear? > >> > >> > > > > Yes, I'm 100% sure. > > > >> What happens when you try to rmmod the ALSA modules? Does rmmod > >> crash with an error or does it hang? If it hangs, can you get > >> another task dump showing the hanging process? > >> > > > > Whenever I try rmmoding something, it hangs (no crash) and I'm not > > able to do anything, beside moving the mouse. > > I posted here: http://marc.info/?l=linux-kernel&m=122502213503239&w=4 > > but that's probably not enough, so I will try getting a full dump. > > > Here it is: http://bugzilla.kernel.org/attachment.cgi?id=18452&action=view The task dump shows rmmod waiting for flush_workqueue(). But the events/0 task doesn't appear to be hung, and the task dump taken before running rmmod shows events/0 doing something different. So apparently flush_workqueue() isn't working. Alan Stern -- 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/