Date: Sun, 8 Nov 1998 16:50:23 +0100 From: Eivind Eklund <eivind@yes.no> To: dg@root.com Cc: John Fieber <jfieber@indiana.edu>, current@FreeBSD.ORG Subject: Re: The infamous dying daemons bug Message-ID: <19981108165023.60036@follo.net> In-Reply-To: <199811081517.HAA03267@root.com>; from David Greenman on Sun, Nov 08, 1998 at 07:17:11AM -0800 References: <19981108160934.30826@follo.net> <199811081517.HAA03267@root.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19981108165023.60036>