From owner-freebsd-current@FreeBSD.ORG Tue Feb 27 09:05:54 2007 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 53C3A16A407 for ; Tue, 27 Feb 2007 09:05:54 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.freebsd.org (Postfix) with ESMTP id 2DBFA13C4BC for ; Tue, 27 Feb 2007 09:05:54 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id C63B44A3F9; Tue, 27 Feb 2007 04:05:53 -0500 (EST) Date: Tue, 27 Feb 2007 09:05:53 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Jiawei Ye In-Reply-To: <20070227084214.Y56223@fledge.watson.org> Message-ID: <20070227090505.K56223@fledge.watson.org> References: <20070227084214.Y56223@fledge.watson.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-current Subject: Re: Processes stuck in *unp_m after recent uipc changes 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: Tue, 27 Feb 2007 09:05:54 -0000 On Tue, 27 Feb 2007, Robert Watson wrote: > On Tue, 27 Feb 2007, Jiawei Ye wrote: > >> With the latest uipc locking changes, I experienced a hard lockup on my >> -current machine. Many processes got stuck in *unp_m state and >> ctrl-alt-delete at the console cannot properly restart the machine and I >> had to hard-reset (no coredump available). Is there anyway to diagnose >> this? > > Please configure WITNESS, DDB, and BREAK_TO_DEBUGGER on a box with a serial > console. Then attach the output of "ps", "show alllocks", and "alltrace" to > an e-mail. With any luck, this is a leaked lock in some missed error case > and we can just add a missing unlock. Thanks! Obviously, INVARIANTS also good on general principle. :-) See the handbook chapter on debugging, and in particular live DDB debugging, if you're running into any problems. Robert N M Watson Computer Laboratory University of Cambridge