Re: Time to deprecate crash dump support in stats tools (or KVM-grovelers in general)?

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

On Sat, 5 Apr 2008 12:43:57 -0700
Jason Thorpe <thorpej%shagadelic.org@localhost> wrote:

> NetBSD has taken great steps recently to modernize its kernel.  One
> of those steps has been to use per-CPU data for various subsystems
> (and the list of subsystems employing this technique to gain MP
> scalability is increasing).
> 
> One of the upshots of moving to per-CPU data is that the data must
> be collated in order to be reported.  This works well on live
> systems where sysctl is available.  It doesn't work so well on crash
> dumps; the tools then have to know the specifics of how per-CPU data
> is managed for that particular subsystem and collate the data
> themselves.
> 
> Given this, I think it's time to deprecate crash dump support in
> these tools (e.g. netstat(1)), and, more generally, deprecate
> KVM-groveling except in some very specific circumstances.
> 
What you say makes sense -- but is there a better way to get certain
data from crash dumps?  Or are you saying we should just live without
it?


                --Steve Bellovin, http://www.cs.columbia.edu/~smb