Re: [Xen-devel] dumping a domain's core

[Ian Pratt <Ian.Pratt@xxxxxxxxxxxx>]

> > Right now, the only way to do this is rather grim -- see the auto
> > reboot stuff in xc_dom_create. It polls get_domain_info once a
> > second.
> 
> Hmm. I guess that could work.

Using the new inter-domain comms rings mechanism it'll be easy to
add events for things like this.

> > In the 1.3 tree, if you've got the pages mapped into domain 0
> > they won't go straight back on the free list when the domain dies
> > (as they're referenced counted). You can then write out a core
> > dump.
> 
> I was hoping that I could map them in on demand. I guess there isn't
> any good reason why DOM0 shouldn't have access to everyone's memory
> all the time.

The trouble with mapping them on demand is that as soon as the
domain exits the reference count on the pages will go to zero and
they'll end up on the free list, hence may get overwritten
e.g. by network packets. 

Rather than destroying a domain when it faults, its arguable we
should just mark it as a zombie, and then rely on user-space
domain0 tools to issue a 'destroy' on the zombies, after writing
a coredump if required.

This would be an easy hack to add for you purposes.

You could create the coredump by modifying the xc_linux_save
function.

Cheers,
Ian


-------------------------------------------------------
SF.Net is sponsored by: Speed Start Your Linux Apps Now.
Build and deploy apps & Web services for Linux with
a free DVD software kit from IBM. Click Now!
http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel