From owner-freebsd-current@FreeBSD.ORG Mon Nov 20 09:04:37 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 0102E16A416 for ; Mon, 20 Nov 2006 09:04:37 +0000 (UTC) (envelope-from bakul@bitblocks.com) Received: from mail.bitblocks.com (bitblocks.com [209.204.185.216]) by mx1.FreeBSD.org (Postfix) with ESMTP id 08AC343D46 for ; Mon, 20 Nov 2006 09:04:22 +0000 (GMT) (envelope-from bakul@bitblocks.com) Received: from bitblocks.com (localhost.bitblocks.com [127.0.0.1]) by mail.bitblocks.com (Postfix) with ESMTP id 71B205B3E for ; Mon, 20 Nov 2006 01:04:36 -0800 (PST) To: freebsd-current@freebsd.org Date: Mon, 20 Nov 2006 01:04:36 -0800 From: Bakul Shah Message-Id: <20061120090436.71B205B3E@mail.bitblocks.com> Subject: unkillable qemu: sleeping in devdrn state X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Nov 2006 09:04:37 -0000 With a fairly recent -current kernel qemu sleeps in "devdrn" state and is unkillable. /proc doesn't have qemu's pid entry but it does show up in a ps listing! This bug is not 100% repeatable but close enough. AFAIK this problem appears only when kqemu is used with qemu. This refcounting related problem has been reported for a number of other devices. In one such thread (on cvs-all, Subject: Re: cvs commit: src/sys/kern kern_conf.c) Tai-hwa Liang has analyzed the problem and suggested a workaround for a couple of devices. Rather than mucking with all the device drivers, I hope a global fix is possible. Perhaps the original fix by Tor Egge is not the only way to fix the bug? I haven't analyzed the problem so likely I am talking through my hat. "You are in a maze of twisty little passages, all alike"