Subject: Re: gif can cause kernel to hang
To: Greg Troxel <gdt@ir.bbn.com>
From: Jeff Rizzo <riz@boogers.sf.ca.us>
List: tech-net
Date: 02/10/2004 13:04:46
On Tue, Feb 10, 2004 at 10:03:04AM -0500, Greg Troxel wrote:
> 
> Or, force __HAVE_GENERIC_SOFT_INTERRUPTS to be off, so that
> gifnetisr() is called from gif_output instead of being deferred.


Ah HAH.  Once I managed to get this working directly with gifnetisr(),
it was enlightening...  because the problem DOESN'T HAPPEN. 
Instead, it logs this message to console:

Feb 10 20:56:52  /netbsd: gif_output: recursively called too many times(2)

...which I wondered about the first time I looked in if_gif.c;
it's clear someone already thought of this, and set up some
recursion detection to avoid it.  Apparently, this detection doesn't
work with the interrupt deferred.  I'll look into this a little further...

+j

-- 
Jeff Rizzo                                         http://boogers.sf.ca.us/~riz