From owner-freebsd-current Sun Nov 8 07:50:52 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA22043 for freebsd-current-outgoing; Sun, 8 Nov 1998 07:50:52 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from ns1.yes.no (ns1.yes.no [195.204.136.10]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA22038 for ; Sun, 8 Nov 1998 07:50:50 -0800 (PST) (envelope-from eivind@bitbox.follo.net) Received: from bitbox.follo.net (bitbox.follo.net [195.204.143.218]) by ns1.yes.no (8.9.1a/8.9.1) with ESMTP id QAA10344; Sun, 8 Nov 1998 16:50:24 +0100 (CET) Received: (from eivind@localhost) by bitbox.follo.net (8.8.8/8.8.6) id QAA04915; Sun, 8 Nov 1998 16:50:24 +0100 (MET) Message-ID: <19981108165023.60036@follo.net> Date: Sun, 8 Nov 1998 16:50:23 +0100 From: Eivind Eklund To: dg@root.com Cc: John Fieber , current@FreeBSD.ORG Subject: Re: The infamous dying daemons bug References: <19981108160934.30826@follo.net> <199811081517.HAA03267@root.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.89.1i In-Reply-To: <199811081517.HAA03267@root.com>; from David Greenman on Sun, Nov 08, 1998 at 07:17:11AM -0800 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, Nov 08, 1998 at 07:17:11AM -0800, David Greenman wrote: > >On Sun, Nov 08, 1998 at 09:22:50AM -0500, John Fieber wrote: > >> One question: Is the problem "sticky"? By that I mean, if it is > >> triggered by a memomry shortage, is something in the kernel > >> corrupted that tends to kill/corrupt daemons from that point in > >> time on, or is it just something that affects isolated processes. > > > >All daemons running at that point seems to get something corrupted. > >If you restart the daemon, it won't happen again until you again run > >out of memory (or whatever it is that trigger the corruption). > > brk(2) will fail and return ENOMEM if the system is low on swap space. phkmalloc() checks for this. Anyway; why does it do this? It does not look like it actually needs to do this, and if we do a memory overcommit, it seems to me that we could do it all the way (or at least have a sysctl to make it do it all the way). I'm also sorely missing a sysctl to turn off memory overcommit... (I don't know the VM system well enough to implement it myself, and I feel very uncomfortable with doing changes in it.) > If the application (phk malloc or the caller of malloc?) isn't > prepared for this, it may end up with a NULL pointer that it doesn't > expect - perhaps not even tripping over it until sometime later. I'm pretty sure this is not the problem. Inactive daemons seems start dying, and I don't always get the "out of swap space" message that comes with setting swap_pager_full. The symptoms are that when the daemon fork after a 'daemons dying occurrance', they will immediately get a sig11 on the child fork. Eivind. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message