Re: ddb_enable="YES" by default?

On Friday, September 05, 2014 5:08:07 pm Peter Wemm wrote:
> On Friday 05 September 2014 13:51:24 Craig Rodrigues wrote:
> > On Fri, Sep 5, 2014 at 7:54 AM, John Baldwin <jhb_at_freebsd.org> wrote:
> > > Probably at least 50% of the time when I work with a user on a bug report,
> > > I ask them to go into kgdb and run specific commands to extract more
> > > detailed info (print some struct, etc.).
> > 
> > Sure, I understand, but you are not working with every user who
> > encounters a kernel panic in FreeBSD.  For the average or casual
> > FreeBSD user, such as desktop
> > users of FreeBSD or PC-BSD, wouldn't it be better
> > to have ddb_enable="YES" be the default in FreeBSD?  The ddb script
> > there does a fairly reasonable
> > job of gathering some useful info which can be analyzed later, and
> > then rebooting the box.
> > 
> > For more expert users, or people developing products, they can set
> > ddb_enable="NO"
> > and do more advanced debugging.  Or hook into /etc/rc.d/ddb and define
> > a different
> > ddb script which doesn't do textdumps on kernel panic.
> 
> I think what John was saying was at that point it's too late.  The loss of the 
> crash dump means the one shot at getting more information is gone.
> 
> For reproducable crashes, yes, an end user could just flip the bit.  But for a 
> one-off, it's too late.

Also, crashinfo is already enabled by default.  If a user enables crash dumps
in the installer, they will have a nice /var/crash/core.txt.N that they can
post to the mailing lists just as easily as the text dump you envision.  And in
fact, I've seen our users already doing this.  (Have you looked at a
/var/crash/core.txt.N file yet?)

-- 
John Baldwin