cvs commit: src/sys/alpha/alpha support.s src/sys/i386/i386 swtch.s src/sys/kern kern_shutdown.c src/sys/sys systm.h

[Nate Lawson]

On Tue, 20 Jan 2004, Robert Watson wrote:
> On Tue, 20 Jan 2004, Don Lewis wrote:
>
> > It would be extremely helpful to preserve the panic message and
> > (optionally) the backtrace across the reboot.  Crash dumps may not
> > always be possible for any number of reasons (swap smaller than RAM,
> > /var/crash too small or overflowing with previous crash dumps, crash
> > dump takes too long ...).  This is especially true in cases where the
> > machine crashes and reboots unattended.
>
> Actually, I was having a very similar conversation with Bill Paul this
> afternoon.  We were discussing dropping a copy of the kernel message
> buffer onto the header of swap space on panic, if possible, and then
> dropping them in /var/log/crash.log for management by newsyslog.  Then the
> natural response to "My machine spontaneously reboots" becomes "Look for
> something recent in /var/log/crash.log", as opposed to "You'll need to
> enable crash dumps, set up a serial console", etc.  It's also something we
> could turn on by default, as opposed to crash dumps, which would otherwise
> consume of alot of disk space.

Excellent idea.  That along with the backtrace() output would be very much
appreciated.

-Nate