From owner-freebsd-hackers@FreeBSD.ORG Fri Jul 18 12:15:01 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 68ACF37B401 for ; Fri, 18 Jul 2003 12:15:01 -0700 (PDT) Received: from mail.speakeasy.net (mail13.speakeasy.net [216.254.0.213]) by mx1.FreeBSD.org (Postfix) with ESMTP id 52B5043FB1 for ; Fri, 18 Jul 2003 12:15:00 -0700 (PDT) (envelope-from jhb@FreeBSD.org) Received: (qmail 28730 invoked from network); 18 Jul 2003 19:14:59 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender )encrypted SMTP for ; 18 Jul 2003 19:14:59 -0000 Received: from laptop.baldwin.cx (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.9/8.12.9) with ESMTP id h6IJEvGI029380; Fri, 18 Jul 2003 15:14:57 -0400 (EDT) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.4 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <3F17B3AE.1FD5CAC6@mindspring.com> Date: Fri, 18 Jul 2003 15:15:12 -0400 (EDT) From: John Baldwin To: Terry Lambert cc: freebsd-hackers@freebsd.org cc: Robert Watson Subject: Re: running 5.1-RELEASE with no procfs mounted (lockups?) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jul 2003 19:15:01 -0000 On 18-Jul-2003 Terry Lambert wrote: > Pawel Jakub Dawidek wrote: >> +> truss Relies on the event model of procfs; there have been some >> +> initial patches and discussion of migrating truss to ptrace() but >> +> I don't think we have anything very usable yet. I'd be happy to >> +> be corrected on this. :-) >> >> Hmm, why to change this behaviour? Is there any functionality that >> ktrace(1) doesn't provide? > > It can interactively run in another window, giving you realtime > updates on what's happening up to the point of a kernel crash. > With ktrace, you are relatively screwed. > > Another good example is that it dump out information that ktrace > can't, because of where it synchronizes. Some people recently > have been seeing "EAGAIN" when they haven't expected it, with > the process exiting immediately after that, with no real clue > as to where in the code it's happening (e.g. which system call); > truss will show this, if run in another terminal window, but > ktrace will not (yes, I know it should; it doesn't. If you can't > reconcile this with how you think ktrace should work, then fix it). Since ktrace logs all syscall entries and exits, it should seem that a kdump after the process had exited would show which syscall returned EAGAIN quite easily. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/