From owner-freebsd-current Tue Aug 4 10:04:43 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id KAA11278 for freebsd-current-outgoing; Tue, 4 Aug 1998 10:04:43 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from alpo.whistle.com (alpo.whistle.com [207.76.204.38]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id KAA11247 for ; Tue, 4 Aug 1998 10:04:28 -0700 (PDT) (envelope-from julian@whistle.com) Received: (from daemon@localhost) by alpo.whistle.com (8.8.5/8.8.5) id KAA23612; Tue, 4 Aug 1998 10:00:53 -0700 (PDT) Received: from current1.whistle.com(207.76.205.22) via SMTP by alpo.whistle.com, id smtpdk23599; Tue Aug 4 17:00:46 1998 Date: Tue, 4 Aug 1998 10:00:36 -0700 (PDT) From: Julian Elischer To: Garrett Wollman cc: current@FreeBSD.ORG, dillon@backplane.com, hag@ai.mit.edu Subject: Re: Bizarre deadlock In-Reply-To: <199808041505.LAA01850@khavrinen.lcs.mit.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG was there any 'mount' operation going on? there are some suspicious paths related to locking mounts and the root vn julian On Tue, 4 Aug 1998, Garrett Wollman wrote: > My Diablo news box is falling over at regular, annoying intervals. I > had initially thought it was some sort of priority-inversion deadlock, > but now it looks even more serious.... > > After spending about 45 minutes tracing through the system with DDB, I > found: > > 1) Most processes are blocked on the inode for the root directory. > (Of course, this means that any time a process wakes up and tries to > do some I/O, it will get blocked.) > > 2) I could follow the chain of inode locks down through NINE > processes. The process holding the root directory should only have > been using it to do a lookup. > > 3) The lock on the inode at the end of the chain was wanted by three > processes, but was either totally free, or was being held shared > (oops, no way to tell by whom). I didn't write down enough > information, unfortunately, to identify precisely which inode this > was. > > -GAWollman > > -- > Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same > wollman@lcs.mit.edu | O Siem / The fires of freedom > Opinions not those of| Dance in the burning flame > MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message