From owner-freebsd-current Mon Nov 18 13: 9:58 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 266EA37B401 for ; Mon, 18 Nov 2002 13:09:57 -0800 (PST) Received: from mail.speakeasy.net (mail13.speakeasy.net [216.254.0.213]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9EFCD43E6E for ; Mon, 18 Nov 2002 13:09:56 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 12454 invoked from network); 18 Nov 2002 21:10:03 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) by mail13.speakeasy.net (qmail-ldap-1.03) with DES-CBC3-SHA encrypted SMTP for ; 18 Nov 2002 21:10:03 -0000 Received: from laptop.baldwin.cx (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.6/8.12.6) with ESMTP id gAIL9s2D028212; Mon, 18 Nov 2002 16:09:54 -0500 (EST) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.2 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: Date: Mon, 18 Nov 2002 16:09:58 -0500 (EST) From: John Baldwin To: John Baldwin Subject: Re: Lock order reversals in sys_pipe.c and kern_sig.c Cc: Kris Kennaway , current@FreeBSD.ORG, tanimura@FreeBSD.ORG, Alfred Perlstein Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On 18-Nov-2002 John Baldwin wrote: > > On 18-Nov-2002 Alfred Perlstein wrote: >> * Kris Kennaway [021118 12:01] wrote: >>> On Mon, Nov 18, 2002 at 11:39:01AM -0800, Alfred Perlstein wrote: >>> >>> > Well now they are, I will investigate as time permits. >>> >>> Thanks. >>> >>> > I'm still in a holding pattern about adding more debugging info to >>> > lockd now that we're in release candidate mode. I may ask for a >>> > branch to be done, but i'm not sure yet. >>> >>> Feel free to give me non-committed patches to test :-) >> >> GRR, witless always gives me the locations of the correct lock >> order, never the locations of the incorrect ones, so here, try this >> and give me a backtrace, it should nail you with extreme prejudice >> when you get what i think is the wrong order: > > This is why there is a static lock-order list that you can add to. > For example: > > Index: subr_witness.c > =================================================================== > RCS file: /usr/cvs/src/sys/kern/subr_witness.c,v > retrieving revision 1.130 > diff -u -r1.130 subr_witness.c > --- subr_witness.c 11 Nov 2002 16:36:20 -0000 1.130 > +++ subr_witness.c 18 Nov 2002 20:42:35 -0000 > @@ -205,6 +205,9 @@ > { "uidinfo hash", &lock_class_mtx_sleep }, > { "uidinfo struct", &lock_class_mtx_sleep }, > { NULL, NULL }, > + { "sigio lock", &lock_class_mtx_sleep }, > + { "pipe mutex", &lock_class_mtx_sleep }, > + { NULL, NULL }, > /* > * spin locks > */ At some point I may add a userland function that allows you to specify an order to witness at runtime. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message