From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 2 Dec 2001 14:02:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 2 Dec 2001 14:02:09 -0500 Received: from vindaloo.ras.ucalgary.ca ([136.159.55.21]:5567 "EHLO vindaloo.ras.ucalgary.ca") by vger.kernel.org with ESMTP id ; Sun, 2 Dec 2001 14:01:59 -0500 Date: Sun, 2 Dec 2001 12:01:58 -0700 Message-Id: <200112021901.fB2J1wM11465@vindaloo.ras.ucalgary.ca> From: Richard Gooch To: William Lee Irwin III Cc: linux-kernel@vger.kernel.org Subject: Re: [BUG] wait_for_devfsd_finished deadlock In-Reply-To: <20011201191113.A1034@holomorphy.com> In-Reply-To: <20011201191113.A1034@holomorphy.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org William Lee Irwin, III writes: > While testing 2.4.17-pre1 with some other patches, a situation > reminiscent of a deadlock arose. mutt(1) would block indefinitely > while opening a large mbox, and all further calls to sys_open() > would block indefinitely. > > After some further testing to isolate the problem, I reproduced this > behavior in the vanilla 2.4.17-pre1 kernel. The sysrq output showed > a number of processes with the following call trace in the devfs > core: Your sh process appears to be hung in wait_for_devfsd_finished(). It would be helpful to know what devfsd was doing at this time. If it were hung internally (in user-space), it would account for this behaviour. However, if devfsd crashes, then devfsd_close() will be called, which will wake any waiters. > And the following call traces elsewhere: Are these related? cron -> pipe_wait() procmail -> interruptible_sleep_on_locked() exim -> sys_wait4() Maybe these are just waiting on mutt(1)? > Further diagnostic information is available upon request. That's what I like to hear. Set CONFIG_DEVFS_DEBUG=y and boot with "devfs=dall" and send me the (verbose) kernel logs. That should show the sequence of events that lead to this. > Mr. Gooch, your attention to this matter is much appreciated. Just "Richard" is fine. I'm not a fan of formality. Regards, Richard.... Permanent: rgooch@atnf.csiro.au Current: rgooch@ras.ucalgary.ca