Subject: Re: unable to dump kernel core
To: Antti Kantee <firstname.lastname@example.org>
From: David Holland <email@example.com>
Date: 11/05/2007 21:21:51
On Sun, Nov 04, 2007 at 10:26:13PM +0200, Antti Kantee wrote:
> For some time now I've been unable to get a kernel coredump from a system.
> At first I thought the system merely hung without panicking, but recently
> I discovered that it was in fact either "syncing disks" or "dumping to .."
> which made the system hang (this was fairly difficult to see from X).
> I tried it in qemu also with the same result. It seems that the I/O
> for reading the swap device disklable never finishes and it is waited
> for indefinitely:
Is it deadlocked?
IME, after a FS-related panic, "syncing disks" usually deadlocks, or
at least it seems to.
I wonder if it would be worth writing a general-purpose deadlock
detector and turning it on when LOCKDEBUG is set...
- David A. Holland / firstname.lastname@example.org