Subject: Re: i386 1.4Q hangs nonrandomly?
To: None <firstname.lastname@example.org>
From: maximum entropy <email@example.com>
Date: 01/27/2000 15:11:49
>From: Jason Thorpe <firstname.lastname@example.org>
>Date: Thu, 27 Jan 2000 08:58:24 -0800
>On Thu, 27 Jan 2000 04:44:32 -0500 (EST)
> maximum entropy <email@example.com> wrote:
> > When it hung I was running: [lots of stuff]
>do you have DDB enabled in your kernel? If so, dropping into DDB
>while running X is going to give the appearance of a "hang".
Yes, I do.
>I'm thinking what happened there is that you ran out of kernel virtual
>address space, and went boom.
>softdeps is known to be pretty evil with memory management (Frank and
>I have some ideas on how to fix it, but there's a decent bit of work
>involved). These other applications that you ran could certainly put
>a strain on your KVA space, as well...
OK, that sounds like a perfectly reasonable explanation. Especially
in combination with the "livelock" softdeps bug being discussed in
another thread, all this is starting to make a little bit more sense
I'll remove DDB from the kernel, and see if I get a crashdump next
time instead of a lockup.
By the way, does "options XSERVER_DDB" have any effect on how the
system behaves during a panic with X running? Or does it only enable
the F12 keystroke? I'd rather not enable that option, because 1) F12 is
mighty close to backspace, and I don't feel like educating my wife
about DDB, and 2) I already learned the hard way from the pmax port,
that a single-key entry to DDB doesn't mix well with a house full of
cats. But if it will help get more information about these hangs, I
could enable it at least for a few days.